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HUMAN  HISTOLOGY 


IN    ITS   RELATIONS   TO 


DESCRIPTIVE  ANATOMY,  PHYSIOLOGY,  AND  PATHOLOGY. 


iiil^  ^aux  Punbrfb  anir  ®^irtg-cf  o«r  llbstratbns  on  SUToob. 


BY 

E.  K  PEASLEE,  A.  M.,  M.  D., 

PROFESSOR  OF  PHYSIOLOGY  AND   PATHOLOGY  IN   THE  NEW  YORK   MEDICAL  COLLEGE  ;    OP 

ANATOMY  IN  DARTMOUTH  COLLEGE;    AND  OF  SURGERY  IN  THE 

MEDICAL  SCHOOL  OP  MAINE. 

MEMBER  OF  THE  AMERICAN  MEDICAL  ASSOCIATION;    OF  THE  NEW  YORK  ACADEMY 

OP  MEDICINE;    OF  THE  NEW  YORK  PATHOLOGICAL  SOCIETY;    OP 

THE  SOCIETY  OF   STATISTICAL  MEDICINE,  ETC. 


'Maxime  in  minimis 


PHILADELPHIA: 

BLANCHARD    AND    LEA. 

1857. 


Entered  according  to  the  Act  of  Congress,  in  the  year  1857,  by 

BLANCH  A  RD   AND   LEA 

in  the  Clerk's  Office  of  the  District  Court  of  the  United  States  in  and  for  the 
Eastern  District  of  Pennsylvania. 


pniLADELPniA : 

T.    K.   AND  p.  O.  COLLINS,  PUINTKUS. 


f 


TO 

R.  D.  MUSSEY,  M.D.,  LLD., 

WHOSE    PROFESSIONAL    SKILL,    SCIENTIFIC   ACCUEACY, 

AND    MORAL    INTEGRITY, 

INCITED    THE   AUTHOR'S   FIRST   DESIRE    TO   ENTER 

THE  MEDICAL  PROFESSION, 

IS    MOST    RESPECTFULLY    INSCRIBED. 


^ 


• 


\ 


Digitized  by  the  Internet  Arciiive 

in  2010  with  funding  from 

Open  Knowledge  Commons 


http://www.archive.org/details/humanhistologyinOOpeas 


PREFACE. 


The  plan  of  the  following  work  was  formed  nine  years  ago; 
since  which  time  the  author's  annual  courses  of  lectures  have  been 
arranged  in  accordance  with  it.  Meantime  several  works  have 
appeared  in  Germany,  France,  and  England,  upon  the  subjects 
embraced  in  it ;  but  no  one  including  its  entire  aim,  viz  : — 

I.  To  give  a  connected  view  of  the  simple  chemical  elements^  of  the 

immediate  j^nnciples,  the  simple  structural  elements,  and  the 
proper  tissues,  entering  into  the  composition  of  the  fluids  and 
the  solids  of  the  human  hody. 

II.  To  associate  with  the  structural  elements  and  the  tissues,  their 

function  ivhile  in  health,  and  the  changes  they  undergo  in 
disease. 

In  the  prosecution  of  his  object,  the  author  has  drawn  more 
especially  upon  the  work  of  Eobin  and  Yerdeil  in  the  first  part; 
that  of  Lehmann  in  the  division  including  the  fluids;  aad  on 
Kolliker's  excellent  work  in  the  part  on  the  tissues  proper.  He 
has  not  hesitated,  indeed,  sometimes  to  use  the  language  of  the 
latter,  when  sufficiently  concise.  He  has  not,  however,  embarrassed 
the  text  by  references  to  the  various  authorities  whence  materials 
have  been  derived ;  except  in  instances  where  views  varying  from 
those  of  previous  writers  are  advanced,  as  being,  in  the  authors 
judgment,  the  most  satisfactory  at  the  present  time. 

In  regard  to  the  dimensions  of  the  minute  structural  elements, 
Kolliker  has  been  more  especially  relied  upon.  And  as  this  work 
is  intended  especially  for  those  who  use  the  English  language,  they 
are  given  in  fractions  of  an  inch,  instead  of  a  millimetre,  or  a  Paris 
line,  as  has  usually  been  done  by  translators  of  German  and  French 
works,  both  in  England  and  in  this  country. 


VI  PREFACE. 

An  experience  of  sixteen  years  as  a  public  teacher  of  anatomy, 
physiology,  and  surgery,  has  confirmed  the  author's  conviction  that 
the  only  rational  method  of  imparting  a  knowledge  o1  function  is 
by  associating  with  the  latter  all  that  is  known  of  the  forms  and 
relations  of  the  structural  elements,  and  of  their  chemical  composi- 
tion, in  each  part  and  organ.  Pathological  anatomy,  moreover,  and 
therefore  pathology,  can  be  rationally  understood  only  as  we  take 
the  same  point  of  departure.  As  the  student  should,  however, 
study  the  last  mentioned  departments  after  acquiring  a  knowledge 
of  the  healthy  structure  and  functions,  the  pathological  conditions 
of  the  tissues  are,  in  the  present  volume,  specified  in  closer  type ; 
as  intended  to  be  more  especially  studied  on  a  second  reading  of 
the  work.  The  same  remark  also  applies  to  the  parts  which  con- 
cern the  structure  of  the  lower  animals. 

Some  typographical  errors,  overlooked  in  the  pressure  of  other 
professional  occupations,  will  be  corrected  at  once  by  the  intelligent 
reader;  excepting,  perhaps,  those  referred  to  at  the  end  of  the 
volume.  Some  portions  compiled  for  it,  relating  to  pathological 
and  comparative  histology,  have  also  been  omitted,  to  avoid  render- 
ing it  formidable,  from  its  size,  to  medical  students;  to  whom,  and 
to  the  profession,  it  is  submitted  as  the  first  American  work  on 
the  subjects  of  which  it  treats. 

New  York,  October,  1857. 


TAELE  or  CONTENTS. 


GENERAL  REMARKS 


PAGE 

33 


PART  I. 

STCECHIOLOGY, 


FIRST  DIVISION. 

Toe  simple  chemical  elements  entering  into  the  stkcctdee  of  the  human 

BODY  (15   in  number) PRACTICAL  REMARKS  .... 


35 


SECOND  DIVISION. 

The  immediate  principles  of  which   the  tissues  of  the  human  body  are 

composed  (84)  .......        38 

Classification  of  the  immediate  principles  .  .  .  .39 

Tabular  arrangement  of        "  "  .  .  .  .40 

List  of  otlier  substances  sometimes  regarded  as  immediate  principles    .         41 


1st  group  of  IMMEDIATE  PRINCIPLES. 
Class  Fh'st. 

IMMEDIATE  PRINCIPLES  OF  MIXEEAL  ORTrtiN, 

Division  £.  Gaseous,  or  liquid  principles,  au.l  those  not  saline  (5) 

1.  Oxygen      ...... 

2.  Hydrogen  .  .  .  .  , 

3.  Nitrogen    ..... 

4.  Carbonic  acid         ..... 

5.  Water,  its  amount,  source,  and  use  in  the  body 

Division  II.  The  saline  principles  (salts,  19) 

General  remarks    ...... 

1.  Chloride  of  sodium  .... 

2.  Chloride  of  potassium       .... 


43 
43 
43 
44 
44 
45 

47 
47 
49 
50 


TABLE    OF   CONTENTS. 


PAGE 

3.  Fluoride  of  calcium  ••....         51 

4.  Hydrochlorate  of  ammonia  .  .  .  .  .51 

5.  Carbonate  of  lime  ......         51 

6.  Carbonate  and  bicarbonate  of  soda  .  .  .  .52 

7.  Carbonate  of  potassa        ......         53 

8.  Sulphate  of  soda  .......         53 

9.  Sulphates  of  potassa  and  lime     .  .  .  .  .53 

10.  Basic  phosphate  of  lime  ......         54 

11.  Phosphate  of  magnesia     ......         55 

12.  Ammonio-magnesian  phosjjhate  .  .  .  .  .56 

13.  Neutral  and  acid  phosphates  of  soda       .  .  .  .57 

14.  Phosphate  of  potassium   ......         58 

15.  Carbonate  of  Magnesia     ......         58 

Class  Second. 

IMMEDIATE  PRINCIPLES  FOKMED  WITHIN  THE  BODY  BY  DIS-ASSIMILATIOS. 

General  remarks  ........         58 

Division  I.  Acid  and  saline  principles  of  organic  origin         .  .  .60 

1.  Lactic  acid  .......         60 

2.  Uric  acid  and  the  urates  ......         61 

3.  Hipijuric  acid        .......         64 

4.  Oxalate  of  lime     .......         64 

5.  Pneumic  acid        .......         67 

Ihrision  II.  Neutral  nitrogenized  immediate  principles  .  .  .67 

1.  Creatine     ........         67 

2.  Creatinine  .......         68 

3.  Urea  ........         68 

4.  Cystine      ........         69 

Dicinion  III.  Sugars  (neutral  non-nitrogenized  principles)    •  .  .69 

Remarks    .........         69 

1.  Hepatic  or  diabetic  sugar  (glucose)  .  .  .  .70 

2.  Sugar  of  milk  (lactose)    ......         72 

Ditigion  IV.  Fatty  principles  ......         73 

General  remarks    ........         73 

Origin  of  the  fatty  principles        ......         74 

1.  Cholesterine  .......         75 

2.  OJeine,  margarine,  and  stearine  .  .  .  .  .76 
Uses  of  the  fatty  principles  in  the  organism        .             .             .             .77 

Practical  remarks      .......         79 


2d  GROUP  OF  IMMEDIATE  PRINCIPLES. 
Class  Third. 

ORGANIC  SUBSTANCES,  OR  COAGDLABLE  PEINCIPLE8. 

General  remarks  ...... 

Clafsification  of  the  organic  immediate  principles     . 


80 
83 


TABLE   OF   CONTENTS, 


IX 


PAG  K 

Division  I.  Tliose  naturally  in  a  fluid  state    .  .  .  .  .83 

1.  Pancreatine  .......         83 

2.  Ptyaline    ........         83 

3.  Mucosine  ........         84 

4.  Alliumen  ;  its  properties  ;  its  pathological  relations — Origin  and 

use  of  albumen — Practical  remarks       .  .  .  .84 

5.  Albuminose  .......         87 

6.  Caseiue,  its  properties  and  iises    .  .  .  .  .88 

7.  Fibrine  ;  its  properties  ;  origin  ;  uses  in  the  organism    .  .         89 

Its  coagulation  as  modified  by  various  agents   .  .  .89 

Remarks         ........         92 

JHvision  II.  Solid  or  demi-solid  organic  immediate  principles  .  .         9G 

1.  Globuline  .......         96 

2.  Crystalline  .  .  .  .  .  .  .96 

3.  Musculine  ;  origin  and  uses — Remarks    .  .  .  .97 

4.  Osteine  ;  origin  and  uses — Remarks  .  .  .  .98 

5.  Cartilageine ;   uses — Remarks      .  .  .  .  .99 

6.  Elasticine  ........       100 

7.  Keratine    ........       100 

Division  III.  Coloring  or  colored  organic  substances  .  .  .  101 

1.  Urrosacine  .......  101 

2.  Bile  pigment  .......  101 

3.  Hsematine  ;  origin ;  uses  ......  102 

Hsematoidine  ;  crystals  of  the  blood      ....       102 

4.  Melanine   ........       103 


X  TABLE    OF    CONTENTS. 

PART  II. 

HISTOLOGY. 

PAGE 

Definitions — subdivisions,  etc.  ......       105 

FIRST  DIVISION. 

THE  SIMPLE  HISTOLOGICAL  ELEMENTS. 

CHAPTER    I. 

HOMOGENEOUS   SUBSTANCE. 

Description — Two  forms — Origin  —  Functions — Distribution — Its  patbological 

states         .........       107 

CHAPTER    II. 

SIMPLE  MEMBRANE. 

Two  forms — Properties — Distribution — Basement-membrane  ;  its  uses  .       109 

CHAPTER    III. 

SIMPLE  FIBRE. 

Description — Distribution — Uses  ......       112 

CHAPTER    IV. 

CYTOLOGY. 

Elements  of  the  cell.  1.  The  cell-wall ;  2.  Tlie  contained  fluid  ;  3.  The 
granules  ;  4.  The  nucleus.  How  affected  by  acetic  acid — Free  nuclei — 
Pathological  developments  of  nuclei.  1.  Tubercle,  its  chemical  analy- 
sis ;  2.  The  glomerulus,  or  exudation-corpuscle.  5.  The  nucleolus  ;  not 
necessarily  developed  from  fibrine,  the  latter  not  being  the  only  plastic 
element  of  the  blood         .......       114 

Cytogeny,  or  development  of  cells.  I.  Free  cell-development ;  described. 
II.  From  pre-existing  cells.  A.  Endogenous  cell-development,  b.  De- 
velopment of  cells  by  division — Physiology  of  cells:   1.  Their  growth; 

2.  The  nature  of  the  contents  of  cells ;  3.  Functions  of  cells — absorp- 
tion, secretion,  and  contraction     ......       120 

Pathological  changes  in  cells.     1.   Fatty  degeneration;  2.  Pigmentary  do.  ; 

3.  Dropsy  ;  4.  Crystalline  deposits  ;  5.  Atrophy  .  .  .129 
The  primordial  cells.     Schwann's  discovery  .....       130 

Isolated  Cells. — I.  Pigment  cells. — Their  strnoturc — Distribution  in  the  Ne- 
gro, and  the  Albino — Freckles — Peculiar  forms  of  pigment  cells,  in  the 


TABLE   OF   CONTENTS.  XI 

PACK 

choroid,  sclerotica,  &c. — Their  distribution  in  the  lower  animals — Color 
of  the  hair  and  eyes — Pigment  in  sebaceous  glands  of  the  skin — De- 
velopment of  pigment  cells  ;  efl'ects  of  solar  light  upon — Functions  of 
pigment  cells — Regeneration  of  do.  .....       131 

Pathological  formations  of  i)igment  cells — 'Melanosis,  ephelis,  moles,  &c.         .       136 

II.  Cancer  cells. — Forms  of  cancer — Cancer  nuclei  —  Their  nucleoli  —  Six 
forms  of  cancer  cells.  1.  Polygonal;  2.  Caudated ;  3.  Fusiform;  4. 
Concentric;  5.  Compound  or  mother  cell ;  6.  Agglomerated  cell  .       137 

Elements  liable  to  be  mistaken  for  cancer.  1.  Corpuscles  of  fibro-plastic 
tissue ;  2.  Fibro-plastic  cells  ;  3.  Enchondromatous  tumors  ;  4.  Pus- 
corpuscles  ;  5.  Tubercle-cori)uscles ;   6.  Epithelial  cells  .  .       142 

The  value  of  the  microscope  in  the  diagnosis  of  cancer         .  .  .       143 

SECOND  DIYISION. 

HYGROLOGY.— THE  FLUIDS  OF  THE  HUMAN  BODY. 

Cytoid  corpuscles  common  to  several  of  the  fluids — Description  of — Their 

chemical  reactions — Development — Functions  of  cytoid  corpuscles        .       145 

CHAPTER     I . 
HISTOLOGICAL  RELATIONS  OF  THE  BLOOD.     (^Lymph  and  Chyle.) 

I.  Lymph. — 1.  The  liquor  lymphs.     2.  Its  histological  elements — Its  origin 

—Uses        .........       147 

II.  Chyle. — 1.  The  liquor  chyli.     2.  Its  histological  elements.     Its  quan- 

tity— Origin — Uses  .......       149 

HI.  The  Blood. — Its  physical  properties — Its  coagulation — The  liquor  san- 
guinis, and  the  blood-corpuscle    ......       151 

1.  The  liquor  sanguinis. — Chemical  analysis — Its  fibrine — Water — 
Albumen  —  Fat  —  Glucose — Other  organic  constituents — Mineral 
constituents  ;  chloride  of  sodium  and  potassium,  carbonate  of 
ammonia,  etc. — Origin  of  the  liquor  sanguinis — Uses  of  its  dif- 
ferent elements — Filjiine  not  the  only  plastic  element  of  the  blood 
— Albumen  is  so  likewise — The  latter  is  probably  the  plastic  ele- 
ment of  the  blood — What  then  are  the  uses  of  fibrine      .  .       152 

2.  The  blood-corpuscles. 

A.  The  colorless  corpuscles. — Their  cell-membrane — Their  con- 

tents— Their  size  and  origin — Uses — Vitality  of  the  blood 

due  to  them,  the  fibrine,  and  the  red  corpuscles    .  .159 

B.  The  colored  corpuscles. — Their  size — Do.  in  the  lower  animals 

— Chemical  analysis  of  do. — Cell-membrane — Contents — 
"  Fibrinous  flakes" — Tendency  to  sink,  of  the  corpuscles — 
Their  color  as  changed  by  difi'erent  agents  and  circum- 
stances— Amount  of  corpuscles  in  the  blood — Their  num- 
ber— Analysis  of  the  blood  as  a  whole — Origin  of  the  red 
corpuscles  from  the  white — Function  of  red  corpuscles — 
Duration  of  their  existence  .  .  .  .162 


XU  TABLE    OF    CONTENTS. 


Quantity  of  blood  in  tlie  human  body  .  .  .       172 

Variety  in  composition  of  the  blood  in  different  physiological 
conditions  ;  sex,  pregnancy,  age,  during  digestion,  &c. — 
Do.  in  the  lower  animals — Difl'erent  composition  of  the 
blood  in  different  vessels :  1.  Arteries  and  veins;  2.  Por- 
tal vein  ;  3.  Hepatic  vein  ;  4.  Placental  vessels  ;  5.  Veins 
of  extremities ;  6.  Menstrual  blood  .  .  .       173 

Pathological  states  of  blood — in  inflammation  ;  fevers ;  cholera  ;  dysentery ; 
acute  exanthemata  ;  puerperal  fever ;  Bright's  disease  ;  plethora ;  ause- 
mia  ;  chlorosis ;  leucaemia  ;  pyiemia  ;  carcinoma  ;  diabetes  ;  etheriza- 
tion— Diseases  iu  which  each  of  the  elements  of  the  blood  is  increased 
or  diminished         ........       170 

CHAPTER    II. 

SEROUS  SECRETIONS,  AND  TRANSUDATIONS. 

Distinction  between  secretion,  transudation,  and  exudation  .  .  .       179 

1.  The  serous  secretions. — Distinguished  from  others  so  called — Their 

normal  quantity — Origin — Uses         .....       180 

2.  Transudations. — Enumeration  of — Pathological  do. — Transudation 

results  from  a  physical  necessity  in  certain  circumstances — Ex- 
plain them  —  Resemble  blood-serum  in  chemical  composition  — 
Quantity  of  albumen  in ;  do.  of  salts  ;  do.  fibrine — Fat  in  them  ; 
bile  pigment,  urea,  &c. — Quantity  of  Transudations — Uses  .       181 

3.  Exudations. — Definition  of  an  exudation — How  differing  from  transu- 

dation— Contain  i.o  histological  elements  at  first — Their  origin — 

Uses    .........       184 

Varieties  of  exudations  —  Changes  occurring  in  them ;  absorption,  or- 
ganization, and  suppuration — Circumstances  determining  between 
organization  and  suppuration  of  exudations  .  .  .       186 

Origin  and  character  of  jius. — 1.  Pus-serum  ;  2.  Pus-corpuscles;  nuclei 
and  contents  of  the  latter — How  long  a  time  necessary  for  the 
formation  of  pus — Character  of  true  pus. — "  Sterile"  cells — Uses  of 
pus — Suppuration  a  destructive  process — When  desirable  .  .       189 

CHAPTER    III. 

THE  MUCOUS  AND  THE  GLANDULAR  SIX'KETIONS. 

Section  First. — Mucus. 

Mucus  secreted  by  epithelial  cells  alone — The  membrane,  as  such,  having 

no  special  function — Mucus  varies  in  composition    .             .             .  194 

1.  Liquor  Muci. — 2.  Mucus  corpuscles,  so  called          .             .  196 

Quantity  secreted  by  mucous  membranes               .             •  197 

Its  origin      .......  197 

Uses  of  mucus         ......  198 

Three  varieties  of  mucus    .  .  .  .  .198 

Relations  of  synovia  to  mucus        ....  198 

The  gastric  fluid. — Description — Chemical  composition — Pcjisin —Acids  of 

the  gastric  juice — Its  origin — Quantity  iu  twenty-four  houid — Uses      .  198 


TABLE    OF    CONTENTS.  Xill 

I'a<;k 
Intestinal  fluid. — Description — Morphological  elements — Fluid  constituents — 

its  quantity — Origin — Uses  ......       200 

Section  Second. — The  Glandular  Secretions. 

I.  Milk. — Description — Colostrum — Milk-globules — Analysis  of  its  fluid 

portion — Circumstances  aifecting  the  amount  of  caseine — of  sugar — 
of  salts  and  of  fat — Quantity  in  twenty-four  hours — Origin — Uses 
of  milk — Milk  of  lower  animals        .....       202 

II.  jSejnew.— Description  ;  1.  Liquor  seminis  ;  2.  Spermatozoids — Semi- 

nal granules — Recognition  of  semen — Origin — Uses  .  .       206 

III.  Glandular  Secretions  discharged  into  the  Alimentary  Canal. 

1.  Saliva. — Description — Its  characters  as  obtained  from  the  dif- 

ferent glands  —  Origin  —  Uses  —  Does  not  normally  convert 
starch  into  sugar  ......       209 

2.  Bile. — Its  properties,  chemical  analysis,  organic    constituents, 

mineral  constituents — Biliary  concretions — Its  amount — Origin 

— Fourfold  function  of  the  bile  ....       210 

3.  Pancreatic  fluid. — Description — Its   chemical   analysis — Pan- 

creatine— Quantity  in  twenty-four  hours — Origin  and  uses       .       213 

4.  Urine. — Description — Normal  morphological    elements — abnor- 

mal elements — Chemical  analysis — Urea,  uric  acid,  creatine, 
and  creatinine  ;  its  mineral  constituents — Substances  passing 
unaltered  into  the  urine — Abnormal  organic  constituents  of 
urine — Sugar  normally  in  it  during  pregnancy — Quantity  of 
urine  in  twenty- four  hours — Its  origin  and  uses  .  .214 

Urinary  deposits,  list  of — Urinary  concretions,  table  of — 

Uric  acid  most  frequently  their  nucleus  .  .       222 

5.  Lachrymal  fluid. — Description — Origin — Uses      .  -  .       225 

CHAPTER    IV. 

THE  CUTANEOUS  SECRETIONS. 

I,  Sebaceous  secretions. — Not  all  precisely  identical — How  modified  by  in- 

flammation— Acarus  folliculorum — Analysis  of  sebaceous  fluid — Rela- 
tions of  the  sebaceous  glands  to  the  hair  follicles — Vemix  caseosa — 
Castoreum — Their  origin — Uses   ......       225 

II.  Perspiration. — The  sweat-glands — Analysis  of  sweat — Gases  contained 

in  it — Amount  in  twenty-four  hours — Origin — Uses — Effects  of  "  check 

of  the  perspiration"  explained     ......       228 

THIRD  DIVISION. 

THE  TISSUES. 
Classification  of  the  Tissues. 

C  H  A  P  T  E  R    I . 

epithelium,  nails,  and  hair. 
Section  First. — Epithelium. 

Definition — Form  and  contents  of  epithelial  cells — Their  si^e — Five  va- 
rieties of  epithelium  ......       235 


XIV  TABLE   OF    CONTENTS. 

PAGE 

1.  Scaly  epithelium. — a.  Simple  scaly — Distributiou — Peculiarities,     b. 

Compound  scaly — Distribiitiou— Peculiarities — Its  modifications  in 

the  lower  animals      .......       238 

2.  Conoidal  epithelium. — A.   Simjjle  conoidal — Distribution — Peculiari- 

ties.    B.  Compound  conoidal — Distribution  .  .  .       241 

3.  Ciliated  epithelium. — Cilia  described,  tlieir  action  and  uses — Distri- 

bution of  ciliated  epithelium — Peculiarities  .  .  .       243 

Development  of  epithelium — Its  reparation — Functions  of  the  several 

kinds  of  eiiitlielium — Action  of  various  agents  upon  .  .       244 

Patholofjical  conditions  of  epithelium — Epithelioma — Papillomata — Epi- 
thelial cancer — New  formations  of  epithelium — Peculiar  appear- 
ances of  epithelium  of  the  tongue  in  disease — Fungous  growths 
upon — Oidium  albicans  ......       247 

Section  Second. — The  Nails. 

Are  a  modification  of  the  epidermis — Bed  of  the  nail — Divisions  of  the 
nail   itself — Its   structure — Growth  of  nails — Time    necessary  for 
their  development — Regeneration — Uses       ....       249 
Patholo(jicnl  states  of  the  nails      ......        252 

Section  Third — The  Hairs. 

Subdivisions  of  a  hair  :  1.  Shaft ;  fibrous  substance  ;  its  color  ;  cuticle  ; 
the  medullary  substance.  2.  Hair-sac;  root-sheath;  the  papilla; 
chemical  composition  of  hair ;  physical  properties ;  distribution 
and  size  of  the  hairs ;  number  on  a  given  surface — Development 
of  the  hair — Periodical  shedding  of — Uses  and  physiological  rela- 
tions of  the  hair — Its  sudden  changes  in  color         .  .  .       253 

Pathological  developments  of  hair  .....       267 

CHAPTER    II. 

YELLOW  FIBROUS  (ELASTIC)   TISSUE. 

Its  three  varieties  of  form — Description  of — Arranged  in  three  principal  modes 
in  the  various  organs — Vessels  of  elastic  tissue — Chemical  composition 
— Not  acted  upon  by  acetic  acid — Its  properties  and  uses — Distribution 
of  yellow  fibrous  tissue — Distribution  in  the  lower  animals       .  .       268 

Development  of  elastic  tissue — Nuclear  fibres — Growth  of  elastic  tissue — Is 

not  regenerated     ........       269 

Patholo(jic(d  new  formations  of  elastic  tissue  .  .  .  .  .       274 

CHAPTER    III. 

WniTE  FIBROUS   (COLLAGENOUS)  TISSUE. 

Description — Contains  no  nerves  or  lymphatics — Its  chemical  composition — 
Its  properties  and  uses — Distribution — Structure  of  tendons  and  liga- 
ments, and  fibro-cartilages  —  Fibrous  membranes  —  Structure  of  the 
cornea — Contains  no  vessels         ......       275 

Distribution  of  white  fibrous  tissue  in  the  lower  animals — Development  of 

white  fibrous  tissue — Its  growth  and  reparation  .  .  .       282 

Pa//(o/o//)Va/ .s/rr/f.s  and  new  formations  of  collagenous  tissue  .  .       283 


TABLE   OF   CONTENTS.  XV 

CHAPTER    IV. 

AREOLAR  TISSUE. 

PAGE 

Distinguished  from  connectivo  tissue — Description — Its  two  fibrous  elements, 

and  its  areolae — Contents  of  the  latter  .....  284 
Chemical  composition  and  properties  of  areolar  tissue — Its  vessels — Uses — 

Distribiition — Peculiarities  ......       287 

The  subcutaneous  areolar  tissue — Description — Relations  to  it  of  fat-cells  .  289 
Development  of  areolar  tissue :  1.  In  repair  by  granulation ;  2.  In  union 

by  adhesion — Mr.  Paget's  experiments — Its  regeneration  .  ,       291 

Pathological  states  and  new  formations — Hyperti'ophy — CEdema — Dropsy — 

Pneumatosis — Subcutaneous  areolar  tissue  the  seat  of  fatty  tumors       .       293 

CHAPTER    V. 

ADIPOSE   TISSUE. 

Adipose  or  fat-cells — Their  peculiarities — Contents — Intercellular  connect- 
ive tissue — Its  peculiarities  in  the  lower  animals — Its  chemical  compo- 
sition .........       295 

Distribution  of  adipose  tissue — Peculiarities  in  this  respect ;  illustrated  by 

epitaphs     .........       299 

Circumstances  modifying  the  deposit  of  fat    .  .  .  .  .       302 

Distribution  of  adipose  tissue  in  the  lower  animals — Use  of  fat  as  a  tissue — 

Its  development,  growth,  and  regeneration  ....       303 

Pathological  states  and  new  formations  of  adipose  tissue — Atrophy — Hyper- 
trophy— Adipose  tumors,  or  lipomata — Encysted  tumors — Cholesteatoma       306 

Fatty  degeneration,  or  stearosis :  1,  of  bone;  2,  of  heart ;  3,  of  paralyzed 
muscles ;  4,  of  kidney ;  5,  of  liver ;  6,  of  arteries  (atheroma) — Fat 
abounds  in  encephaloid    .......       309 

CHAPTER    VI. 

CARTILAGE. 

Varieties :  1.  Simple  cellular  cartilage ;  2.  Compound  cartilage — Descrip- 
tion—  Cartilage  cells  —  Intercellular  homogeneous  substance  —  Peri- 
chondrium ........       313 

Chemical  composition  of  cartilage — Its  properties  and  uses — Its  develop- 
ment .........       315 

Pathological  states  and  new  formations  of  cartilage — Ulceration — Loose  car- 
tilage, so  called,  in  joints — Enchondroma — Atrophy — Necrosis — Fatty 
degeneration  ........       319 

CHAPTER    VII. 

OSSEO0S  TISSUE,  AND  THE  BONES. 

Section  First. — Osseous  Tissue. 

Its  ultimate  granules — The  lacunae  and  pores — The  vascular  canals  of 
osseous  tissue — 1.  Cancellated  bone  structure ;  the  cancelli ;  their 


XVI  TABLE    OF   CONTENTS. 

PAGE 

contents  ;  2.  Compact  bone  structure  ;  its  general  lamellae  ;  special 
lamellae — Haversian  rods — "Various  forms  of  lacunae  and  pores — 
Chemical  composition  of  osseous  tissue — Its  changes  in  pregnancy 
— Its  changes  in  various  diseases — Sclerosis — Osteoporosis — Rachi- 
tis— Softening — Caries — Properties  and  uses  of  the  osseous  tissue 
— Its  distribution — Its  distribution  in  the  lower  animals     .  .       321 

Section  Second. — Structure  of  Bones. 

Their  bloodvessels — Lymphatics  do  not  exist — Nerves  of  the  bones — 
The  marrow — Its  uses — Do.  in  birds — Periosteum — Articular  car- 
tilages— Synovial  membranes  ;  are  not  closed  sacs — Interarticular 
fibro-cartilages — Connection  of  tendons  and  ligaments  with  bones — 
Structure  of  the  diarthrodial  articulations — The  amphiarthroses  or 
symphyses — The  synarthroses — Properties  of  the  bones — Their  uses 
— Their  strength  as  columns  of  support        ....       336 

Development  of  Bones  :  1.  Cancellated  bone-structure — cancelli  formed 

by  absorption  .......       350 

2.  Develojiment  of  the  compact  bone-substance — Pores  formed  by  ab- 
sorption— Development  of  secondary  bones — Remai'ks — Weight  of 
bone  formed  in  a  day — Fractures — Growth  of  bone — Its  reparation       35(> 

Pathological  conditions  and  new  formations  of  bone — Hypertrophy — 
Atrophy — Osteostearosis — Necrosis — Osteoporosis — Cancerous  and 
tuberculous  deposits  in  bone — New  formations  of  bone  (true  ossifi- 
cation) ........       365 

CHAPTER   VIII. 

DENTAL  TISSUE,  AND  THE  TEETH. 

Section  First. — Dental  Tissue. 

Relations  of  dentine,  enamel,  and  cementum  :  1.  Dentine — its  inter- 
tubular  substance  ;  its  chemical  analysis  ;  the  dentinal  tubuli.  2. 
Enamel — description  of  its  fibres,  and  chemical  composition.  3. 
Cementum — chemical  analysis  of.     Remarks  .  .  .       367 

Section  Second. — Structure  of  the  Teeth. 

1.  Cortical  portion.  2.  Dental  pulp — its  vessels  and  nerves;  the  gum  : 
periosteum  of  the  alveolus.  Properties,  uses,  and  development  of 
the  teeth — Time  of  appearance  of  the  different  teeth  .  .       374 

Pathological  states  of  the  teeth  :  Exostosis  ;  necrosis  ;  caries  ;  teeth  co- 
lored in  jaundice — developed  in  abnormal  situations  .  .       382 

CHAPTER    IX. 

MUSCULAR  (contractile)  TISSUE,  AND  THE  MUSCLES. 

Section  First. — Muscular  Tissue. 

1.    Contractile  fibre-cells,  or  smooth  muscular  fibre :  Description — Chemi- 
cal composition — Their  distribution — Peculiarities  in  the  uterus — 
Their  distribution  in  the  lower  animals — Functions  of  the  con- 
tractile fibre-cells — Their  development — Regeneration  .  .       383 
Pathological  conditions  and  now  formations  of  contractile  fibre-colls  : 

Hypertrophy — Atrophy — Fatty  degeneration  .  .  .       391 


TABLE   OF   CONTENTS.  Xvii 

PAGE 

2.  Striated  muscular  tissue :  Description  of  striated  fibres — A.  Myolem- 
ina  ;  b.  Myoline.  The  fibrillse — Peculiarities  in  the  heart — Chemi- 
cal composition,  and  physical  properties  of  striated  muscular  tis- 
sue. 1.  The  "  muscular  juice  ;"  2.  The  musculine.  Analysis  of 
muscular  substance — Color  of  muscular  fibres — their  elasticity. 
Distribution  of  striated  muscular  fibres — their  elasticity  and  pecu- 
liar forms  in  the  lower  animals.  Development  of  striated  muscu- 
lar fibre — Growth — Functions  of  do. — Modifications  of  contractility 
of  do. — Spasm — Paralysis — The  rigor  mortis  .  .  .       392 

Patholofjical  conditions  and  new  formations  of  striated  muscular  fibre  : 
Hypertrophy — Atrophy —  Stearosis — Softening  —  Rupture — Concre- 
tions— Ossification — Parasites — New  formations  in  testis  and  ova- 
rian tumors    ........       405 

Section  Second. — ■Structure  of  the  Muscles. 

Divisions  of  fusiform  muscles — Aponeurosis — Tendon  —  Belly — the 
perimysium — Connection  of  the  tendons  with  muscular  fibres — 
Connection  of  do.  with  bones — Vessels  of  the  muscles — Nerves — 
their  final  subdivision — Peculiarities  of  muscular  nerves  in  lower 
animals  .  .  .  .  .  .  .  .       408 

Accessory  organs  of  the  muscles :  1.  Muscular  envelops,  or  fascife.  2. 
Ligaments  of  the  tendons.  3.  Tendinous  sheaths  and  synovial 
sacs.  4.  Fibro-cartilages  and  sesamoid  bones.  Physical  proper- 
ties of  the  muscles — Physiological  remarks — Tonicity — Sensibility 
— Muscular  sound — Heat  developed  by  muscular  contraction  .       417 

Development  of  the  muscles — Do.  tendons  •  •  .  .       421 

Pathological  states   of  muscles   and   accessories — Talipes — Ganglion 

Housemaid's  knee     .......       422 

CHAPTER    X. 

NERVOUS  TISSUE,  AND  THE  STRUCTURE  OF  THE  NERVOUS  STSTEIT. 

Section  First. — The  Nervous  Tissue. 

1.  The  fibrous  or  tubular  nerve-tissue :  Various  sizes  of  nerve-fibres  • 

their  structural  elements  ;  the  neurilemma ;  neurine ;  the  axis- 
fibre  ;  the  medulla  or  pulp.  Fine  nerve-fibres  not  peculiar  to  the 
sympathetic  system — Fibres  of  Remak — Distribution  of  nerve- 
fibres — Chemical  composition  of  do. — Functions  of  do.        ,  423 

Development  of  nerve-fibres  :  1.  Those  in  nerve  trunks  ;  2.  Peripheral 
terminations  of  nerve-fibres  ;  3.  Nerve-fibres  in  the  central  organs  ; 
growth  of  nerve-fibres  ......       431 

Pathological  states  and  new  formations  of  nerve-fibres  :  Atrophy Divi- 
sion of  fibres — Neuroma — New  formations  of,  in  pleuritic  adhe- 
sions, &c.        •••.....       433 

2.  Nerve-cells:     Various   forms  —  Contents — Distribution.      Chemical 

composition  and  physical  properties — Functions  of  nerve-cells 

development  of  do.    .......       434 

Pathological  stales  and  new  formations  of  nerve-cells      .  .  .       437 

2 


Xviii  TABLE    OF   CONTENTS. 

PAGE 

Section  Secoxd. — Structure  of  the  Nervous  System. 

1.  Structure  of  the  nerves  ......       438 

Perineurium — Bloodvessels  ......       438 

A.  The   spinal  nerves  ;   tlieir  roots  ;  ganglion-cells  and  ganglion- 

fibres — Pacinian  bodies  .....       439 

B.  Ganglionic  nerves  ;  their  ganglion-cells  and  ganglion-fibres — 

Distribution  of  the  latter  .  .  .  •  .444 

c.  The  encephalic  nerves  :  1.  The  fifth  pair  ;  2.  The  motor  nerves  ; 
3.  Those  of  special  sensation ;  first  pair,  and  optic  nerve ; 
optic  chiasma.  Five  layers  of  the  retina ;  acoustic  nerve. 
Distribution  of  vestibular  and  cochlear  branches         .  .       446 

2.  Structure  of  the  nervous  centres. 

A.  The  spinal  cord ;  longitudinal  and  horizontal  fibres  of  its  white 

matter  ;  fibres  of  its  gray  substance  ;  various  forms  of  cells  in 
latter       ........       455 

Do  the  fibres  of  the  cord  ascend  to  the  brain  ?  .  .  .458 

B.  Structure  of  the  encephalon. 

1.  Medulla  oblongata  and  pons  Varolii.  2.  Cerebellum ;  its 
gray  matter  ;  peculiar  cells  in  ferruginous  layer.  3.  The 
ganglion  of  the  cerebrum ;  corpora  quadrigemina ;  optic 
thalami  ;  corpora  striata.  4.  Cerebral  hemispheres  ;  their 
white  substance  ;  their  gray  matter  .  .  .       460 

The  membranes  and  vessels  of  the  nervous  centres. 

1.  Pia  mater;  plexus  choroides  ;  ependyma  ventriculorum.  2. 
Arachnoid.  3.  Dura  mater ;  vessels  of  preceding  membranes  ; 
lymphatics  of  do.  ;  nerves  of  do.  ;  vessels  of  encephalon  and 
cord.  Chemical  composition  of  the  nervous  centres  ;  quantity 
of  fat  in  the  brain  ;  do.  of  phosphorus  •  .  .       468 

Functions  of  the  nervous  system  .....       474 

Pathological  states  of  the  nervous  centres  ....       475 

CHAPTER    XI. 

THE  MEMBRANES. 

Typical  forms  of  papillse,  villi,  and  glands  ....       475 

I.  The  skin. 

A.  The  corium  ;  its  structure  ;  the  tactile  papillse  .  .  .       476 

B.  Basement-membrane,     c.  Epithelium — Epidermis,  and  stratum 

Malpighianum — their  absolute  and  relative  thickness.     Che- 
mical composition,  and  physical  properties  of  the  skin — its 
bloodvessels,  lymphatics,   and   nerves — Development   of  the 
skin — Regeneration  of  do.  .....       479 

Appendages  and  accessary  organs  of  the  skin  :   1.  Subcutaneous  bursas 
mucosse ;    2.  Sebaceous  glands— Various  forms — Minute  structure 
— Development ;    3.    Sweat-glands — their  number — Volume — Ag- 
gregate length — Minute  structure — Ceruminous  glands       .  .       486 
Functions  of  the  skin       .....••       492 

Pathological  states  of  the  skin  :  1.  Of  the  epithelium  ;  2.  Of  the  corium  ; 

3.  Of  the  sebaceous  glands   ....••       493 


TABLE   OF   CONTENTS.  XIX 

PAGE 

II.  Mpcocs  Membranes  :  Variety  and  structure — their  functions     ,  .      495 

Pathological  states  of  the  mucous  membranes — Atrophy — Inflammatory 

exudations  upon — Ulceration  .....       495 

III.  Serous  Membranes  ;  Structure — are  closed  sacs — functions        .  .      496 

IV.  False  Membranes  :  Usually  confounded  with  coagulated  exudations — 

Are  organized  exudations,  with  vessels — Prone  to  involution — New 
membranes     ........       497 

CHAPTER    XII. 

THE  VASCULAR  SYSTEM. 

I.  The  Heart  :  The  pericardium — Muscular  fibres  of  the  heart — Endocar- 
dium— Valves — Vessels         ......       498 

II,  The  Bloodvessels :  a.  The  arteries;  1.  External  coat;  2.  Middle  coat; 
3.  Inner  coat — Vasa  vasorum — Nerves  of  the  vessels,     b.  The  ca- 
pillaries— Walls  of  simple  membrane  merely — Capillary  plexus — 
"  Vasa  serosa"  do  not  exist,     c.  The  veins — Structure  of  smallest 
veins — Do.  of  medium  size — Do.  of  largest — Veins  presenting  pe- 
culiarity of  structure — Their  valves  ....       500 

III.  Lymphatic  Vessels  and  Glands  :  Capillary  lymphatics — the  largest  do. 

Thoracic  duct — Their  vessels  and  valves      ....       509 

Structure  of  lymphatic  glands — Degeneration  of  the  latter        .  .       510 

Functions  of  the  vascular  system  .....       511 

Development  of  the  heart,  arteries,  and  veins — Do.  of  capillaries  .       511 

Pathological  conditions   and  new  formations  of  vessels — ^Atheroma  in 
1  arteries — Aneurism — Varicose  veins — Fatty  degeneration  of  capil- 

laries ........       513 

New  formations  of  vessels  ......       513 

CHAPTER    XIII. 

structure  of  alimentary  canal  and  its  appendages subdivisions  of  alimentary 

canal. 
A.  Alimentary  Canal. 

1.   Oral  cavity. — Its  mucous  membrane  ;  corium  of  the  latter ;  papillae 
of  do  . ;  papillse  of  the  tongue,  filiform,  fungiform,  and  circumval- 
late ;  their  uses  .......       514 

Pathological  appearances  of  the  tongue     .  .  .  .  .518 

Glands  of  the  oral  cavity;  1.  Mucous;  2.  Simple  follicular;  3.  Com- 
pound follicular  .  .  .  .  .  .  .519 

Salivary  glands     ........       521 

II.  Pharynx. — Its  mucous  membrane  ;  its  glands ;  bloodvessels,  lymphatics, 

and  nerves  ........  522 

III.  (Esophagus. — Its  structure  ......  522 

IV.  Structure  of  the  stomach;  gastric  glands  ;  peptic  cells  ;  bloodvessels  of 
stomach ;  lymphatics,  and  nerves  .....  523 

V.  Structure  of  the  small  intestine. 

Jejunum — Ileum — The  villi ;  size  and  structure  ;  the  laoteals  ;  function 


XX  TABLE    OF    CONTENTS. 


PAGE 


of  the  villi ;  glands  of  the  small  intestines ;  1.  Lieberkuhn's 
glands  ;  2.  Brunner's  glands  ;  3.  Closed  follicles  (Peyer's  glands)  ; 
Peyer's  patches  .......       526 

VI.  Large  Intestine — its  glands :  1.  Lieberkuhn's ;  2.  Peculiar  closed  folli- 
cles ;  its  bloodvessels        .......       ^2>\ 

B.  Appendages  to  the  Alimestakv  Canal. 

1.  Liver. — No  distinct  lobules  in  man  ;  relations  of  vessels  in  its  islets       532 
Capsule  of  Glisson — portal  canals  ;  arrangement  of  hepatic  cells  in  the 

islets  ;  their  connection  with  the  hepatic  ducts;  sacculi  of  the  lat- 
ter ;  capillary  network  of  the  islets.  Chemical  composition  of  the 
liver;  its  functions  ;  pathological  conditions  ;  cii'rhosis  ;  jaundice        533 

2.  Pancreas — its  structure  ;  function  of  pancreatic  fluid  .  .       540 

CHAPTER    XIV. 

THE  URINARY  APPARATUS. 

1.  The  urethra  (of  the  female)  ;  its  structure  ;  2.  The  bladder;  its  muscu- 
lar layers  ;  its  mucous  membrane :  3.  The  ureters  and  pelvis  of  the 
kidney ;  their  fibrous  coat ;  muscular  do.  ;  mucous  membrane ;  4. 
Structure  of  the  kidneys  ;  cortical  and  tubular  portions  :  1.  Tubuli 
uriniferi ;  structure  and  arrangement ;  their  contorted  form  in  the  cor- 
tical portion.  2.  Other  peculiarities  of  the  latter  ;  Malpighian  bodies  ; 
their  number  ;  vessels  of  the  kidney  ;  nerves  ;  chemical  analysis  of 
the  kidney ;  its  function;  development  ....       541 

Pathological  states  of  the  kidney  ......       549 

CHAPTER    XV. 

the  SEXUAL  ORGANS. 

L   Sexual  Apparatus  of  the  Male. 

1.  The  urethra;  its  corpus  spongiosum  —  Muscular  layers;  mucous 
membrane ;  the  penis  ;  its  corpora  cavernosa ;  muscular  fibres  in 
their  trabeculse  ;  its  arteries,  lymphatics,  nerves — Prostate  gland  ; 
its  muscular  portion,  glandular  portion.  2  and  3.  Vesiculze  semi- 
nales,  with  the  ejaculatory  ducts  and  vasa  deferentia  ;  their  struc- 
ture. 4.  The  testes  ;  their  fibrous  tunic — Lobules  of  parenchyma 
— Seminiferous  tubes,  their  contents — The  spermatozoids,  their 
movements — Ejaculatio  seminis        .....       550 

n.   Sexual  Organs  of  the  Female. 

1.  The   vulva;    mucous   membrane;    numerous   papillae  —  Sebaceous 

glands — Bartholini's  glands  .....       559 

2.  The  vagina  ;  muscular  layer  ;  mucous  membrane  ;  its  paipillas  ;  hy- 

men   .........       559 

3.  The  uterus  and  oviducts ;  their  muscular  layers  ;  mucous  membrane 

of  uterus  ;  presents  no  papillae  ;  numerous  glands — Mucous  mem- 
brane of  canal  of  cervix  uteri ;  its  rugre  and  glands — Mucous  mem- 
brane of  Fallopian  tubes — Round  ligaments — Broad  ligaments — 
Uterine  sinuses  .......       560 


TABLE   OF   CONTENTS.  XXI 

PAGE 

Changes  of  the  uterus  at  the  menstrual  period  and  in  pregnancy — Do. 

immediately  after  latter        .  .  .  .  .  .504 

4.  The  ovaries  ;  structure  ;  ovisac  ;  its  membrane  ;  its  contents  ;  mem- 

brana  granulosa  ;  germinal  disk  ;  ova  ;  vitelline  membrane  ;  zona 
pellucida  ;  yolk  ;  germinal  vesicle  ;  germinal  spot — Corpus  luteum 
of  menstruation — Do.  of  pregnancy — Function  of»female  genitalia 
— Slight  sensibility  of  the  interior  of  the  uterus      .  .  .       565 

5.  The  lacteal  gland  ;  its  structure — Muscular  fibres  in  the  mammilla 

and  areola — Teiminal  lactiferous  ducts         ....       569 

CHAPTER    XVI. 

RESPIRATORY  ORGANS. 

Air  passages :  1.  Nasal  passages  and  upper  portion  of  pharynx ;  structure 
of  mucous  membrane;  its  glands.    2.  Larynx  and  trachea;  their  struc- 
ture ;    do.    of  mucous   membrane  ;    its   glands  ;   ciliated   epithelium ; 
bloodvessels  ;  lymphatics   and  nerves.    3.  Lungs ;  Bronchi  and  their 
subdivisions  ;  muscular  fibres  of  do.  ;  their  mucous  membrane — The 
pulmonary  arteries — The  bronchial  arteries — interlobular   connective 
tissue — pulmonary  lobules  ;  their  structure — Connection  of  the  terminal 
air-tubes  with  the  air-cells  ;   structure  of  the  latter ;   their  number —  ■ 
Capillary  plexus  of  the  lobules,  ......       572 

Function  of  the  respiratory  apparatus  .  .  •  .  .580 

Development  of  the  lungs       .......       580 

Pathological  states  of  the  lungs — Emphysema — Deposits  of  pigment — Red 
and  gray  hepatization — (Edema — Fatty  degeneration — Tuberculous  and 
cancerous  deposits — Gangrene      ......       581 

CHAPTER    XVII. 

BLOOD- VASCULAR  GLANDS. 

1.  Spleen,  its  serous  and  fibrous  coat ;  its  parenchyma — The  trabeculse  and 

pulp  ;  cells  of  the  latter — The  Malpighian  bodies  ;  their  structure — Ves- 
sels of  the  spleen  ;  lymjihatics  ;  nerves  ;  its  function  ;  development     .       583 

2.  Thyroid  gland;  its  structure  ;  chemical  analysis  ;  bloodvessels  ;  lymph- 

atics ;  nerves ;  function  unknown  .....       583 

Pathological  enlargements  of  thyroid  body        .....       589 

3.  Thymus  gland;  structure  of  its  lobules  ;  their  cells  and  nuclei;  distribu- 

tion of  arteries  ;  fluid  inclosed  in  its  cavities ;  its  involution,  commenc- 
ing at  from  twelve  to  twenty  years  ;  function  unknown  .  .       590 

4.  Supra-renal  glands :  1.  Cortical  portion ;  the  cortical  cylinders.     2.  Me- 

dullary substance  ;  its  pale  cells  ;  bloodvessels  of  these  organs  ;  their 
nerves  very  numerous  :  function  unknown  ;  have  no  physiological  con- 
nection with  the  kidney  .......       592 

CHAPTER    XVIII. 

ORGANS  OF  THE  SENSES. 

1.  Organ  of  touch  ........       594 

2.  Of  taste       .........       594 


XXll  TABLE    OF   CONTENTS. 

PAGE 

3.  Of  smell      ••.......      594 

4.  Of  hearing ;  the  internal  ear  .  .  .  .  .  .594 

5.  Eye:  I.  Its  membranes ;  sclerotic  coat ;  choroid  coat ;  veins  of  the  latter ; 

ciliary  zone  and  nerves  ;  the  retina  ;  the  cornea  ;  the  iris  ;  arrangement 
of  its  muscular  fibres  ;  its  color  .  .  .  .  ,  .594 
II.  The  humori  of  the  eye ;  the  aqueous  humor  ;  the  crystalline  lens ; 
composed  of  tubes  ;  their  appearance  ;  capsule  of  the  lens  ;  the 
latter  not  vascular ;  uses  of  the  lens  ;  its  growth ;  is  some- 
times regenerated  ;  cataract — The  vitreous  body ;  description  ; 
use— The  conjunctiva  ;  the  eyelids  ;  the  tarsi ;  appendages  of 
tlieeye 600 


LIST   OF  ILLUSTRATIONS. 


Part  I.— STCECHIOLOGY. 


FIG. 

PAGE 

'  i  CMoride  of  sodium        .... 
2.  ) 

.     49,  50 

3.  Carbonate  of  lime             .... 

51 

*  i  Phospliate  of  lime          .... 
5.  ' 

.     54, 55 

6.  Ammonio-magnesian  phospliate 

57 

7.  Stellate  crystals  of           do. 

57 

8.  Foliaceous  crystals  of      do.         . 

57 

9.  Rosette  crystals  of           do. 

57 

10.  Calculus  of                       do. 

57 

11.  Uric  acid               ..... 

61 

12.- 

13. 
14. 

■  Uric  acid  rhombs            .... 

.     61,  62 

15. 

16.  Uric  acid,  hourglass  form             .             .             « 

62 

17.  Uric  acid  from  urine        .... 

62 

18.  Uric  acid  on  hair .             .... 

62 

19.  Uric  acid  on  a  fibrinous  cast  of  a  uriniferous  tube 

62 

20  ^ 

*  J-  Uric  acid  calculus           .... 
21.) 

63 

22.  Urate  of  soda       ..... 

.       '      .           63 

23.  Urate  of  soda  calculus     . 

63 

24.  Urate  of  ammonia            .... 

64 

25.  Hippuric  ac'd  crystals      .... 

64 

26.  Oxalate  of  lime  crystals 

65 

27  ^ 

*  >  Oxalate  of  lime               .... 
28.) 

65 

29.  Oxalate  of  lime.     Octah.  dried   . 

65 

30  ^ 

■  J-  Oxalate  of  lime.     Dumb-bell     . 
31.) 

65 

32.  Calculus  of  lime  (mulberry) 

66 

33.  Calculus  of  lime,  section 

66 

34.  Alternating  calculus        .... 

66 

35. 

Creatine   ...... 

67 

XXIV 


LIST   OF   ILLUSTRATIONS. 


FIG. 

36.  Creatinine 

37.  Urea 

38.  Cystine     . 

39.  The  torula  cerevisise 

40.  Fat-globules 

41.  Cholesterine 

42.  Glomeruli,  &c. 

43.  Simple  fibres 

44.  Crystals  from  human  blood 

45.  Crystals  from  blood  of  guinea-pig 


PAGE 

68 
68 
69 
70 
73 
75 
78 
92 
103 
103 


Part  II.— CYTOLOGY. 

46.  Homogeneous  substance  of  cartilage 

47.  Basement  membrane 

48.  Simple  fibres  in  membrana  putaminis 

49.  Simple  fibres  in  inflammatory  exudation 

50.  Fibre-cells  becoming  fibres 

51.  Nuclear  fibres 

52.  Simple  fibres,  &c. 

53.  Typical  cells 

54.  Spermatozoids 

55.  Germinal  spot 

56.  Tubercle  from  peritoneum 

57.  Tubercle  from  lung 

58.  Tubercle  from  mesentery 

59.  Glomeruli  and  granular  cells 

60.  Endogenous  cell-development 

61.  Endogenous  cell-growth  in  a  meliceritious  tumor 

62.  Segmentation  of  vitellus 

63.  Latter  stage  of        do. 

64.  Cells  from  encephaloid  of  tongue 

65.  Development  of  secreting  cells  in  the  creca  of  glands 

66.  Blood-corpuscles  multiplying  by  division 

67.  Multiplication  of  cartilage  cells  . 

68.  Vertical  section  of  cuticle  of  negro 

69.  Pigmentum  nigrum  of  the  eye 

70.  Cells  between  choroid  and  sclerotic  of  sheep 

71.  Cells  on  choroid  of  black  and  of  white  rabbit 

72.  Pigment  cells  of  the  skin  of  lamprey 

73.  Pigment  cells  in  the  tail  of  a  tadpole 

74.  Vertical  section  of  the  skin  of  nose 

75.  Cancer  cells  in  a  fibrous  stroma,  &c. 

76.  Simple  and  compound  cancer  cells 

77.  Melanotic  cancer 

78.  Free  cancer  nuclei 

79.  Polygonal  cancer  cells 

80.  Caudated  cancer  cells 


108 
109 
112 
112 
113 
113 
113 
114 
116 
116 
117 
117 
117 
119 
123 
123 
124 
124 
125 
125 
126 
126 
132 
133 
133 
133 
134 
134 
135 
137 
138 
138 
138 
139 
140 


LIST   OF   ILLUSTRATIONS. 


XXV 


FIG. 

81.  Fusiform  cancer  cells     . 

82.  Fusiform  fibres  of  fibro-pLastic  tissue 

83.  Two  concentric  cancer  cells 

84.  Compound  cancer  cells  . 

85.  Agglomerated  cancer  nuclei 

86.  Spherical  libro-plastic  cells 

87.  Tubercle  corpuscles  distinguished  from 

88.  Young  epithelial  cells    . 

89.  Tessellated  epithelium  . 

90.  Buccal  epithelium 

91.  Ciliated  epithelium  from  air-passages 


PAGE 
140 

141 
141 
141 
141 
142 
142 
143 
143 
143 
143 


THE  FLUIDS. 

92.  Cytoid  corpuscles  .......         145 

93.  Pus-corpuscles  changed  by  acetic  acid  ....         146 

94.  Fibres  in  fibrous  tumors  ......         157 

95.  White  blood-corpuscles  ......         159 

96.  White  corpuscles,  various  phases  of    .  .  .  .  .         160 

97.  Colored  blood-cells  .......         162 

98.  Colored  blood-cells,  shrivelled  by  chemical  agents       .  .  .         165 

99.  Nummular  arrangement  of  do.  .  .  .  .  .  .165 

100.  Development  of  first  set  of  red  corpuscles        ....         168 

101.  Phases  of  blood-corpuscles        ......        168 

102.  Development  of  lymph  and  chyle  corpuscles  into  red  corpuscles  .         169 

103.  Fat  globules  in  blood     .......         174 

104.  Exudation  globules  and  nucleated  fibres  in  pus  .  .  .         190 

105.  Other  elements  mixed  with  pus  .  .  .  .  .         190 

106.  Pus-corpuscles   ........         190 

107.  Sterile  cells,  with  pus-corpuscles  .....         192 

108.  Sputa  of  acute  pneumonitis       .  .  .  .  .  .192 

109.  Mucus-corpuscles  with  epithelial  cells,  &c.        ....         196 

110.  Gastric  peptic  glands      .......         199 

111.  Gastric  favuli     .  .  .  .  .  .  .  .199 

112.  Intestinal  follicles,  &c.  .  .  .  .  .  .  .201 

113.  Milk  globules  and  colostrum  corpuscles  ....         203 

114.  Termination  of  milk  ducts         ......         205 

115.  Ultimate  follicles  of  lacteal  gland         .....         205 

116.  Human  Spermatozoids  .......         207 

117.  Phases  of  development  of  spermatozoids  ....         208 

118.  Biliary  ducts  and  parenchymal  cells  of  liver  ....         212 

119.  Isolated  cells  of  liver     .......         212 

120.  Mucus-corpuscles  and  epithelial  cells  in  urine  .  .  .214 

121.  Pus-corpuscles  in  urine  ......         214 

122.  Colored  blood-coipuscles  in  urine ,         .  .  .  .  .         215 

123.  Fibrinous  cast  of'uriniferous  tube         .....         215 

124.  Fibrinous  cast,  and  epithelial  cells  containing  fat  globules       .  .         215 

125.  Large  organic  globules  .  .  .  .  .  .  .215 

126.  Small  organic  globules  .......        215 


XXVI 


LIST   OF   ILLUSTRATIONS. 


FIG. 

127.  The  torula  in  urine 

128.  Fungoid  growths  in  the  urine  . 

129.  Sarcina  ventriculi 

130.  Structure  of  kidney 

131.  Two  Malpighian  tufts  and  their  relations 

132.  Uriniferous  tube  and  its  epithelial  lining 

133.  The  lachrymal  gland,  &c. 

134.  Acarus  folliculorum 

135.  Simple  sebaceous  follicles  of  skin 

136.  Meibomian  gland 

137.  Ceruminous  gland 

138.  Sweat  gland  and  duct    . 


THE  TISSUES. 

139.  Pavement  epithelium  from  uriniferous  tubes 

140.  Scaly  epithelium  of  serous  membrane 

141.  Epithelium  of  arteries  (horse) 

142.  Scaly  epithelium  of  lymphatics 

143.  Scaly  epithelium  of  left  ventricle  (horse) 

144.  Scaly  epithelium  of  left  auricle  (horse) 

145.  Membrana  granulosa 

146.  Vertical  section  of  epidermis     . 

147.  Epithelial  plates 

148.  Simple  conoidal  epithelium 

149.  Simple  conoidal  epithelium  of  Lieberkuhn's  follicles 

150.  Simple  conoidal  epithelium 

151.  Simple  conoidal  epithelium  (ciliated)   . 

152.  Compound  conoidal  epithelium  (ciliated) 

153.  Epithelial  condylomata 

154.  Epithelial  cancer 

155.  Oidium  albicans 

156.  Transverse  section  of  nail 

157.  Transverse  section  of  nail,  its  body  and  bed 

158.  Relations  of  nail  to  the  cuticle 

159.  Structure  of  Hair 

160.  Plates  of  fibrous  substance 

161.  Plates  of  cuticle  of  hair 

162.  Epithelium  of  root  of  hair 

163.  Cells  of  medulla  of  rodeutia 

164.  Hair  of  bat  and  squirrel 

165.  Cells  of  inner  root-sheath 

166.  Rudiments  of  hair-sac  . 

167.  Development  of  hair 

168.  Development  of  second  eyelashes 

169.  Old  hair  falling  out         . 

170.  First  and  second  forms  of  elastic  tissue 

171  ) 

J-  Tliird  form  of  elastic  tissue     . 
172.) 


LIST   OF   ILLUSTRATIONS. 


xxvn 


PIG. 

173. 
174. 

175. 
176. 
177. 
178. 
179. 
180. 
181. 
182. 
183. 
184. 
185. 
186. 
,187. 
188. 
189. 
190. 
191. 
192. 
193. 
194. 
195. 
196. 
197. 
198. 
199. 
200. 
201. 
202. 
203. 
204. 
205. 
206. 
207. 
208. 
209. 
210. 
211. 
212. 
213. 
214. 
215. 
216. 
217. 
218. 
219. 
220. 
221. 


areolar 


Vessels  of  elastic  tissue 

Formative  cells  of  elastic  tissue 

White  fibrous  tissue 

Vessels  of  tendons 

The  fibrous  tissue  in  the  testis 

Tubular  interspaces  of  the  cornea 

Continuity  of  cornea  into  sclerotica 

Vessels  of  the  sclerotica 

Yellow  and  white  fibrous  tissue,  in  the 

The  areolae  of  areolar  tissue 

Vessels  of  areolar  tissue 

Formative  cells  of  white  fibrous  tissue 

Normal  isolated  fat-cells 

Polyhedral  fat-cells 

Fat-cells  and  conuective  areolar  tissue 

Vessels  of  fat-cells 

Crystals  of  margaric  acid  in  fat-cells 

Crystals  of  spermaceti  in  fat-cells  of  whale 

Fat-cell,  showing  nucleus 


in  indurations 


I  Atrophy  of  fat-cells 


Structure  of  lipoma 
Structure  of  cholesteatoma 
Fatty  degeneration  of  bone 
Fatty  degeneration  of  liver 
Atheroma  in  arteries 

Do.  advanced  stage 

Cells  from  chorda  dorsalis  of  lamprey 
Cellular  cartilage  of  mouse's  ear 
Fibro-cartilage    . 
Reticulated  cartilage 
Groups  of  cells  in  cartilage-cavities 
Vessels  of  articular  cartilage  (foetus) 
Do.  do.  after  birth 

I"  Enchondroma.     External  structure 

Do.  Internal  structure 

Ultimate  granules  of  bone-tissue 
Lacunre  and  pores  of  bone 
Termination  of  pores  on  the  surface  of  bone 
Vessels  in  the  substance  of  the  osseous  tissue 
Spherical  cancellus 

Structure  of  the  cancelli  while  developing 
The  general  (fundamental)  lamellae  of  bone 
Radiation  of  pores  from  the  Haversian  canals 
Various  forms  of  lacunas  and  pores 
Interstitial  osseous  substance    . 
Fibres  of  osteine  in  bone  acted  on  by  acid 


tissue 


&c. 


PAGE 

273 
273 
275 

278 
279 
280 
281 
281 
285 
286 
287 
292 
296 
296 
297 
297 
298 
304 
305 

307 

308 
309 
309 
311 
312 
812 
313 
313 
314 
314 
317 
318 
318 

319 

320 

321 
322 
323 
325 
326 
327 
329 
330 
331 
331 
333 


XXVlll 


LIST   OF   ILLUSTEATIONS. 


FIG. 

222.  Section  of  articular  cartilage     .... 

223.  Section  of  joint  showing  synovial  membrane    . 

224.  Union  of  bone  and  tendon  .... 

225.  Linear  arrangement  of  cartilage-cells  in  developing  bone 

226.  Processes  of  new  bone  projecting  between  rows  of  cartilage  cells 

227.  Formation  of  interrupted  laminae 

228.  Vertical  section  of  sub-periosteal  layer  of  developing  bone 

229.  Development  of  secondary  bones 

230.  Relations  of  the  dentine,  enamel  and  cementum  of  a  tooth 

231.  Tubes  and  intertubular  substance  of  dentine    . 

232.  The  divisions  of  the  dental  tubuli,  and  the  granular  layer 

233.  The  dentinal  globules    ..... 

234.  Transverse  strise  of  enamel-fibres,   and   external   surface   (showing 

their  hexagonal  ends) 

235.  Transverse  strife  of  young  enamel-fibres,  acted  on  by  hydrochloric 

acid      ....... 

236.  The  cementum  of  old  teeth,  containing  Haversian  canals 

237.  The  four  stages  of  development  of  the  teeth    , 

238.  The  closed  sac  in  which  the  enamel  is  formed 

239.  The  dental  pulp,  enamel-sac,  and  development  of  enamel 

240.  Cells  with  prolonged  filaments  forming  the  dentine 

241.  Transformation  of  enamel-pulp  into  enamel-fibres 

242.  j^on-striated  muscular  fibres  as  usually  described 

243.  Contractile  fibre-cells  (smooth  muscular  fibres) 

244.  Contractile  fibre-cells  in  walls  of  the  bloodvessels 

245.  Colossal  contractile  fibre-cell  from  impregnated  uterus 

246.  Contractile  fibre-cell  with  fringed  margin 

247.  Minute  vessels  of  smooth  muscular  tissue 

248.  Contractile  fibre-cells  in  uterus  three  weeks  after  parturition 

249.  Hypertrophy  of  smooth  muscular  fibres  of  stomach    . 

250.  Striated  muscular  fibres  and  fibrillse     . 

251.  The  myolemma  of  striated  fibres 

252.  Anastomosing  muscular  fibres  of  human  heart 

253.  Development  of  striated  muscular  fibres 

254.  Development,  and  effects  of  acetic  acid 

255.  Contracted  state  of  striated  muscular  fibre 

256.  Contracted  state  showing  muscular  fluid  beneath  myolemma 

257.  Hypertrophy  of  striated  muscular  fibres  of  the  heart 
258."  Atrophy  of  striated  muscular  fibres  of  the  heart 

259.  Fatty  degeneration  of  muscular  fibres  of  the  heart 

260.  The  three  subdivisions  of  fusiform  muscles 

261.  Transverse  section  of  a  tendon 

262.  Transverse  section,  showing  elastic  fibres 

263.  Section  of  muscle,  showing  internal  and  external  perimysium 

264.  Union  of  muscular  fibres  with  tendon 

265.  Union  of  muscular  fibres  at  an  acute  angle 

266.  Minute  vessels  of  the  muscles  . 

267.  Minute  vessels  in  the  internal  perimysia 

268.  Nerves  of  the  muscles   . 


LIST   OF   ILLUSTRATIONS. 


XXIX 


FIG. 

269.  Divisions  of  tlie  nerve-fibres  in  muscles 

270.  Multii)le  subdivisions  of  nerve-fibres  in  muscle  of  frog 

271.  Development  of  the  tendons 

272.  Various  sizes  of  nerve-fibres 

273.  The  neurilemma  and  neurine  of  nerve-fibres 

274.  The  axis-fibre  of  a  nerve-fibre  or  tube 

275.  Changes  in  the  medulla  by  various  agents 

276.  Fibres  of  Remak 

277.  Development  of  nerve-fibres 

278.  Development  of  nerve-fibres  at  their  peripheral  extremities 

279.  Various  forms  of  nerve-cells 

280.  Branching  multipolar  nerve-cells 

281.  Perineurium  of  ischiatic  nei've 

282.  Anterior  and  posterior  roots  of  spinal  nerves,  &c 

283.  Structure  of  ganglion  on  posterior  root  of  spinal  nerves 

284.  Ganglion-cells  and  their  nucleated  capsules 

285.  Ganglion-cells  continuous  with  nerve-fibres 

286.  Pacinian  bodies 

287.  Minute  structure  of  Pacinian  bodies 

288.  Structure  of  sympathetic  ganglia 

289.  Ganglion-cells  of  sympathetic  ganglia 

290.  Branches  of  olfactory  nerve 

291.  Fibres  of  the  olfactory  nerve 

292.  Distribution  of  olfactory  nerves  to  the  septum 

293.  The  optic  chiasma 

294.  Nerve-fibres  of  the  optic  nerve 

295.  Section  of  the  retina,  showing  its  five  layers 

296.  Branched  nerve-cells  in  gray  layer  of  retina 

297.  Capillaries  of  gray  layer 

298.  The  rods  and  cones  of  the  bacillar  layer 

299.  Bacillar  layer  seen  from  without 

300.  Plexifoi'm  arrangement  of  cochlear  nerve 

301.  Bipolar  ganglion  cells  interrupting  the  cochlear  nerve-fibres 

302.  Transverse  section  of  spinal  cord 

303.  Course  of  nerve-fibres  in  spinal  cord 

304.  Nerve-cells  of  central  gray  matter  of  the  cord 

305.  Transverse  section  of  medulla  oblongata 

306.  Anterior  view  of  medulla  oblongata 

307.  Posterior  view  of  medulla  oblongata     . 

308.  Cells  of  gray  matter  of  cerebellum 

309.  Ganglia  of  the  cerebrum 

310.  Nerve-cells  of  gray  matter  of  the  convolutions  of  cerebrum 

311.  Fine  nerve-fibres  of  superficial  white  layer  of  cerebrum 

312.  The  ependyma  ventriculorum   .... 

313.  Minute  vessels  of  the  white  and  the  gray  cerebral  substance 

314.  Divisions  of  terminal  arteries  on  entering  convolutions 

315.  Typical  forms  of  cutaneous  papillifi  and  intestinal  villi 

316.  Typical  forms  of  simple  and  compound  glands 

317.  Vertical  section  of  the  skin       .... 


PAGE 
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417 
422 
424 
425 
425 
427 
429 
431 
432 
434 
436 
438 
439 
440 
441 
441 
442 
443 
445 
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447 
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448 
449 
450 
450 
451 
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453 
454 
454 
455 
458 
459 
460 
461 
461 
463 
465 
466 
467 
469 
471 
471 
475 
476 
477 


XXX 


LIST   OF   ILLUSTRATIONS. 


PIG. 

318.  Simple  papillse  of  the  palm 

319.  Compound  papillse  of  surface  of  liand  . 

320.  Section  of  the  epidermis 

321.  Under  surface  of  the  epidermis 

322.  Capillaries  of  the  papillae 

323.  Nerves  of  papillae  and  asile  corpuscles 

324.  Forms  of  sebaceous  glands 

325.  Sebaceous  glands  of  the  nose    . 

326.  Minute  structure  of  sebaceous  glands 

327.  Structure  of  the  glandular  coil  of  the  sweat  glands 

328.  Structure  of  excretory  duct  of  coil  of  the  sweat  glands 

329.  Sebaceous  and  ceruminous  glands 

330.  Anastomosing  muscular  fibres  of  heart 

331.  Elastic  layer  of  semilunar  valves 

332.  Section  of  artery  showing  three  coats   . 

333.  Middle  and  inner  coat  of  arteries 

334.  Internal  elastic  (fenestrated)  layer  of  inner  coat  of  arteries 

335.  External  portion  of  fibrous  layer  , 

336.  Epithelial  cells  of  aorta 

337.  Structure  of  capillaries 

338.  Section  of  vein,  showing  three  coats 

339.  Capillary  lymphatics     .... 

340.  Section  of  walls  of  thoracic  duct 

341.  Structure  of  lymphatics  and  lymphatic  glands 

342.  Development  of  capillaries        ... 

343.  Fatty  degeneration  of  minute  arteries  and  capillaries 

344.  Filiform  papillce  of  tongue         ... 

345.  Nerves  of  filiform  papillae  ... 

346.  Fungiform  papillae  .... 

347.  Papilla  circumvallata    .... 

348.  Racemose  mucous  glands  of  mouth 

349.  Simple  follicular  glands  of  mouth 

350.  Compound  follicular  glands  (tonsil) 

351.  Section  of  walls  of  stomach,  showing  glands   . 

352.  Compound  peptic  and  mucous  glands  . 
553.  Minute  vessels  of  mucous  membrane  of  largo  intestine 

354.  Section  of  wall  of  small  intestine,  showing  villi 

355.  Minute  vessels  of  villi,  and  Lieberkiihn's  follicles 

356.  Villi  with  the  contained  lacteals 

357.  Structure  of  follicles  of  Lieberkiihn 

358.  Minute  vessels  of  mucous  follicles  . 

359.  Section  of  wall  of  small  intestine  and  closed  follicles 

360.  A  solitary  closed  follicle  with  villi 

361.  Peyer's  patches  with  oi)eniugs  of  follicles 

362.  Solitary  closed  follicles  of  large  intestine 

363.  Section  of  hepatic  lobules  showing  vessels 

364.  Transverse  section  of  a  portal  canal 

365.  Human  hepatic  cells      .... 

366.  Network  of  hepatic  ducts 


LIST    OF   ILLUSTRATIONS. 


XXXI 


PIG. 

367.  Network  of  hepatic  ducts,  magnified     . 
3G8.   Hepatic  islets  with  their  radiating  cells 

369.  The  hepatic  cells  within  tubes  of  simple  membrane 

370.  Communication  of  interlobular  ducts  with  preceding 

371.  Narrowest  portion  of  bile-duct,  and  its  epithelium 

372.  Terminal  portion  of  bile-duct,  and  its  epithelium 

373.  Simple  pouches  of  hepatic  ducts 

374.  Compound  pouches  of  hepatic  ducts     . 

375.  Section  of  kidney,  showing  uriniferous  tubes  . 

376.  Stroma  between  tubes  of  kidney 

377.  Relations  of  Malpighian  body  to  arteries  and  tubes  of 

378.  Minute  vessels  of  kidney,  and  of  Malpighian  bodies 

379.  Cast  of  a  tubulus  uriniferus 

380.  Littre's  glands  from  the  fossa  Morgagnii 

381.  Minute  arteries  of  corpus  cavernosum  penis 

382.  Structure  of  vesicuke  semiuales 

383.  Arrangement  of  seminiferous  tubes 

384.  Crecal  extremities  of  seminiferous  tubes 

385.  Structure  of  the  testis    . 

386.  Structure  of  a  spermatic  tube   , 

387.  Spermatophori  and  spermatozoids 

388.  Uterine  mucous  membrane  soon  after  conception 

389.  Papillte  of  vagina  and  cervix  uteri 

390.  Rugae  of  cervix  uteri 

391.  Rugae  of  cervix  uteri,  magnified 

392.  Section  of  a  Graafian  vesicle  (ovisac)  . 

393.  Structure  of  the  human  ovum  . 

394.  Ovary  containing  corpora  lutea 

395.  Corpora  lutea  of  pregnancy 

396.  Structure  of  lacteal  gland 

397.  Smallest  lobules  of  lacteal  gland 

398.  Terminal  cseca  of  lacteal  gland 

399.  Lacteal  gland  of  new-born  infant 

400.  Ciliated  ej)ithelium  of  nasal  passages  . 

401.  Smooth  muscular  fibre  in  bronchi 

402.  Lobular  passages,  and  infundibula  of  lungs 

403.  Air-cells  opening  into  the  infundibula 

404.  Air-cells  opening  into  the  infundibula,  seen  in 

405.  Structure  of  walls  of  air-cells    . 

406.  Capillary  plexus  of  the  air-cells 

407.  Capillary  plexus  of  small  bronchial  tubes 

408.  Tubercles  in  the  air-cells 

409.  Cretaceous  transformation  of  tubercle  . 

410.  Peculiar  fusiform  fibres  in  the  spleen  . 

411.  Cells,  &c.,  of  the  pulp  of  the  spleen 

412.  Malpighian  bodies  of  the  spleen 

413.  Structure  of  Malpighian  bodies  of  the  spleen 

414.  Connection  of  a  Malpighian  body  with  the  sur 

415.  Structure  of  thyroid  gland 


section 


kidney 


rounding  vessels 


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xxxn 


LTST   OF   ILLUSTEATIONS. 


PIG. 

416.  Thyroid  gland,  vesicles  filled  with,  colloid 

417.  Structure  of  thymus  gland 

418.  Minute  vessels  of  thymus  gland 

419.  Section  of  supra-renal  gland 

420.  Cortical  cylinders  of  supra-renal  gland 

421.  Section  of  external,  middle,  and  internal  ear  . 

422.  Membranous  semicircular  canals,  &c.   . 

423.  Termination  of  vestibular  nerves 

424.  The  labyrinth,  laid  open 

425.  Relations  of  labyrinth  to  external  and  middle  ear 

426.  Section  of  the  eyeball   .... 

427.  Sclerotic  and  choroid  coat  of  the  eye    . 

428.  The  ciliary  muscle  and  the  chambers  of  the  eye 

429.  Capillaries  of  the  choroid  coat 

430.  Ciliary  processes  of  the  choroid 

431.  Relations  of  crystalline  lens  and  vitreous  body 

432.  Cells  and  tubes  of  crystalline  lens 

433.  Structure  of  tubes  of  crystalline  lens  . 

434.  The  "  star"  of  the  crystalline  lens 


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HUMAN  HISTOLOGY. 


GENERAL   EEMAEKS. 

The  human  bodj,  when  fully  developed,  is  composed  of  solids 
and  fluids,  in  the  proportion  of  one  of  the  former  bj  weight  to  at 
least  eight  or  ten  of  the  latter.^  All  the  solids  are  permeated  to  a 
greater  or  less  extent  by  the  fluids,  of  which,  also,  water  is  always 
the  principal  constituent.  The  mere  descriptive  anatomist  regards 
the  solids  alone,  as  if  isolated  from  the  fluids  which  form  an  essen- 
tial part  of  them.  But  the  chemical  physiologist  and  the  histologist 
must  study  the  latter  as  well  as  the  former.  The  isolated  fluids, 
also,  as  the  blood,  chyle,  milk,  and  other  secretions,  come  within 
the  domain  of  histology  so  far  as  they  contain  cells,  granules,  nu- 
clei, or  other  histological  elements ;  and  these,  therefore,  as  well  as 
the  tissues,  will  be  embraced  in  this  work. 

Commencing,  however,  with  an  analysis  of  the  human  body  as 
seen  by  the  unaided  eye,  and  omitting  for  the  present  the  isolated 
fluids,  we  find  that  it  is  composed — 

1.  Of  parts  and  organs. 

2.  That  the  organs  are  formed  of  combinations  of  tissues. 

3.  The  tissues  are  composed  of  certain  chemical  compounds  called 
immediate  'princii^les. 

4.  And  the  last  are  formed  by  a  direct  combination  of  a  few  of 
the  siinple  chemical  elements. 

Eeversing  this  view,  we  perceive  that — 

1.  The  simple  elements  unite  to  form  the  immediate  principles. 

2.  The  last  unite  to  form  the  tissues. 

'  A  mummy  of  a  native  of  Teneriffe,  presented  to  Bhimenbacli  by  Sir  Josepli 
Banks,  weighed  but  seven  pounds  and  a  half;  probably  not  more  than  one-sixteenth 
of  the  weight  of  the  same  body  during  life. 

3 


Si  GENERAL   REMARKS. 

3.  And  tlie  tissues,  separately  and  in  combination,  constitute  the 
parts  and  organs  of  wliicli  the  body  consists. 

This  work  will,  accordingly,  consist  of  two  parts — 

Part  I.,  containing  an  account  of  the  simple  elements,  and  of  the 
immediate  principles  of  the  tissues  and  the  fluids,  or  Stcechiology. 

Part  II.,  giving  a  description  of  all  the  tissues,  and  the  fluids  con- 
taining histological  elements,  or  Histology. 


PAET   I. 

S  T  CE  C  II I  0  L  0  G  Y. 


Stgechiology^  comprises  the  classification  and  description  of  the 
simple  chemical  elements,  and  of  the  immediate  principles  which 
enter  into  the  composition  of  the  tissues  and  fluids  of  which  the 
human  body  is  composed. 


FIRST  DIVISION. 

THE  SIMPLE  CHEMICAL  ELEMENTS  ENTERING  INTO 
THE  STRUCTURE  OP  THE  HUMAN  BODY. 

Of  the  sixty-five  simple  bodies  now  (1857^)  known  to  chemists, 
it  is  not  certain  that  more  than  fifteen  are  normal  constituents  of 
th.e  human  body.     These  are — 


1. 

Oxygen. 

6. 

Phosphorus. 

11. 

Chlorine. 

2. 

Hydrogen. 

7. 

Calcium. 

12. 

Fluorine. 

8. 

Carbon. 

8. 

Magnesium. 

18. 

Silicum. 

4. 

Nitrogen. 

9. 

Sodium. 

14. 

Iron. 

5. 

Sulphur. 

10. 

Potassium. 

15. 

Manganesium 

M.  Millon  announced  that  copper  and  lead  also  normally  exist  in 
the  blood-corpuscles  of  man,  and  Orfila  added  arsenic  as  entering 
into  the  composition  of  the  tissues.    These  observations  have,  liow- 

'  From  iToi-^£~ov,  an  element,  and  >^oyo;,  description. 

^  Two  or  three  others  have  jnst  been  auuouinjed,  but  their  discovery  lias  not 
been  confirmed. 


S6  SIMPLE    CHEMICAL   ELEMENTS. 

ever,  not  been  confirmed ;  and  either  of  these  three  substances,  found 
in  the  human  organism,  must  be  regarded  as  accidentally  present. 
Iodine  and  bromine  enter  into  the  composition  of  the  lowest  marine 
animals ;  but  it  is  not  yet  proved,  nor  probable,  that  they  normally 
form  a  part  of  the  human  body,  though  such  an  assertion  has  been 
made. 

The  fifteen  elements  just  mentioned  unite  variously  to  form  the 
immediate  principles  of  the  tissues  hereafter  to  be  considered.  The 
following  is,  however,  a  general  account  of  the  parts  and  the  fluids 
in  which  each  is  found: — 

1-4.  The  first  four  elements  are  found  in  all  the  tissues,  and  most 
of  the  fluids,  except  fat;  the  first  three  in  all  tissues  and  fluids, 
without  exception.  Of  the  first  two  water  is  constituted;  whose 
abundance  in  the  human  organism  has  already  been  alluded  to. 

5,  6.  Sulphur  and  phosphorus  exist  in  the  albuminous  group  of 
immediate  principles  (albumen,  fibrine,  &c.),  and  in  the  tissues  formed 
from  them,  and  all  animal  cells.  They  also  enter  largely  into  the 
composition  of  the  brain — about  j^o  of  its  weight  being  phospho- 
rus. {Von  Bibra.)  Sulphnr  is  a  constituent  of  hair  and  nails,  which 
accounts  for  their  odor  during  combustion.  Both  the  sulphuric  and 
the  phosphoric  acids  exist  in  the  urine,  and  the  latter  in  bones  also, 
in  combination  with  lime  and  magnesia.  Treviranns  believed  that 
spontaneous  combustion  of  the  human  body  may  be  due  to  an  ex- 
cess of  phosphorus  in  it. 

7,  8.  Calcium  and  magnesium  are  found  only  in  the  state  of 
oxides,  i.e.  as  lime  and  magnesia;  and  combined  with  acids  to  form 
salts.  The  phosphate  of  lime  constitutes  about  one-half  the  weight 
of  human  bone,  and  the  carbonate  about  one-tenth ;  the  phosphate 
of  magnesia  amounts  to  the  one-hundredth  part.  Both  these  ele- 
ments also  exist  in  milk,  and  other  fluids. 

9.  Sodium,  in  combination  with  chlorine — i.  e.  forming  common 
salt — exists  in  every  solid  and  fluid  in  the  body.  In  all  other  cases 
it  is  in  the  form  of  an  oxide  (soda),  and,  in  combination  with  acids, 
forms  various  salts  in  the  different  tissues  and  fluids. 

10.  Potassium  also  unites  with  chlorine  to  form  the  chloride  of 
potassium,  the  latter  being  abundant  in  muscular  tissue.  Otherwise 
it  is  in  the  oxide  state — j)^^'^^^^'^ — ^^^^  ^^  combination  with  acids.  It, 
however,  exists  but  sparingly  in  animals,  in  comparison  with  soda, 
while  it  abounds  in  plants. 

11.  Chlorine  combines  with  hydrogen  to  form  the  hydrochloric 


REMARKS.  57 

acid  in  the  gastric  fluid.     In  all  other  cases  it  is  found  as  chloride 
of  sodium  (common  salt),  or  of  potassium. 

12.  Fluorine  is  combined  with  calcium,  in  small  amount,  in  bones. 

13.  Silicum  exists,  oxidized  (as  silica),  in  small  quantity  in  the 
hair,  in  wool  and  feathers,  and  in  the  urine.     It  abounds  in  plants. 

14.  Iron  constitutes  about  ^^Vu  P9.rt,  by  weight,  of  the  blood ;  it 
also  exists  in  hair,  muscle,  milk,  pigment-cells,  and  (a  mere  trace) 
in  the  gastric  fluid.  Iron  always  exists,  also,  in  the  feces,  since 
solid  and  fluid  articles  of  food  contain  more  of  it  than  is  required 
in  the  organism. 

15.  The  oxide  of  manganese  is  found  in  bone  (Kane),  and,  some 
say,  in  the  coloring  matter  of  the  hair.  It  is  separated  from  the 
organism  in  the  bile. 

RemarlxS. — 1.  Our  food  (and  drink)  must  contain  at  least  the  fif- 
teen elements  just  specified,  in  order  to  secure  and  maintain  the 
development  of  the  body.  No  single  article  of  food,  except  milk 
and  eggs,  perhaps,  contains  them  all,  and  hence  the  necessity  for 
variety  of  aliment. 

2.  The  absurdity  of  the  idea  of  some,  that  mineraJs  should  never 
be  used  as  remedies,  is  at  once  apparent.  Ten  of  the  fifteen  simple 
elements  are  minerals,  and  the  rest,  also,  all  enter  into  the  compo- 
sition of  various  mineral  substances.  We  must,  therefore,  take 
minerals  in  all  our  food,  and  this  whether  the  latter  be  animal  or 
vegetable ;  for  all  vegetable  as  well  as  animal  tissues  contain  mine- 
ral substances. 

3,  Nor  is  the  notion  that  no  minerals  except  such  as  form  a  part  of 
the  lody  should  be  used  as  medicines,  any  more  tenable,  for  the 
same  objection  would  hold  against  all  vegetable  remedies,  since  not 
one  of  them  (opium,  lobelia,  &c.)  naturally  enters  into  the  compo- 
sition of  the  body ;  and  thus  the  sole  remedies  remaining  would  be 
the  fifteen  elements  above  named ;  for  if  it  be  said  that  the  active 
principles  of  vegetables,  as  morphia,  quinia,  &c.,  contain  only  the 
elements  above  mentioned  [e.g.  the  four  first  mentioned),  yet  it  is 
true  that  some  of  these  compounds,  as  strychnia,  hydrocyanic  acid, 
&c.,  are  more  dangerous  and  destructive  to  animal  life  than  any 
mineral  substance  known. 


SECOND  DIYISIOI(. 

THE  IMMEDIATE  PRINCIPLES  OF  WHICH  THE  TISSUES 
OF  THE  HUMAN  BODY  ARE  COMPOSED. 

The  immediate  principles  of  the  tissues,  are  tlie  "last  bodies  con- 
stituting the  organism  to  which  the  tissues  can  be  reduced  by  mere 
anatomical  analysis ;  and  which  admit  of  no  further  subdivision 
without  chemical  decomposiliony^  Sugar,  gum,  starch,  cellulose, 
water,  &c.,  are  immediate  principles  to  a  plant ;  and  water,  albu- 
men, fat,  urea,  &c.,  to  an  animal.  The  carbon,  oxygen,  hydrogen, 
&c.,  composing  these  are  the  simple  elements,  or  the  elementary  (or 
mediate)  jDriuciples  of  the  plant,  or  the  animal,  respectively. 

The  expression,  "  immediate  principles,"  is  borrowed  from  Chev- 
reul,  who  thus  defends  its  use:  "Some  scientific  writers  think  this 
expression  objectionable,  since  it  is  not  reasonable  to  apply  the 
word  principle  to  compound  holies.  I  do  not  participate  in  this 
opinion.  For  when  we  consider  in  a  general  way  the  composition 
of  a  salt,  as  established  by  Lavoisier,  it  is  apparent  that  it  is 
constituted  by  the  union  of  an  acid  and  an  alkali,  rather  than  by 
the  elements  of  the  acid  with  those  of  the  alkali,  since  if  these  ele- 
ments are  united  in  other  proportions  than  such  as  constitute  an 
acid  and  an  alkaline  body,  they  no  longer  give  us  the  idea  of  a  salt. 
Hence  it  seems  proper  to  say  that  the  acid  and  the  alkali  are  the 
two  immediate  principles  of  the  salts.  It  is  the  same  with  sugar, 
starch,  gum,  lignine,  &c.,  in  respect  to  a  plant,  and  with  fibrine, 
albumen,  &;c.,  in  respect  to  an  animal.  Those  substances  should  be 
regarded  as  the  immediate  j) J' inciples  of  the  plant  or  of  the  animal  to 
which  they  belong,  while  oxygen,  nitrogen,  carbon,  and  hydrogen 

•  Robin  and  Verdeil's  Anatomical  and  Pliysiological  Cliemistiy ;  3  vols.  p.  18S7, 
%vith  an  Atlas.  For  an  extended  review  of  this  work,  and  many  of  the  facts  intro- 
duced into  this  division,  see  the  Americaji  Medical  Monthly,  for  March,  1855. 


CLASSIFICATION.  39 

are  their  remote  or  elementary  principles'^  It  will  appear  that  the 
three  gases  just  mentioned  are,  however,  also  immediate  jyi'incijjles 
in.  certain  circumstances. 

Thus  the  study  of  the  immediate  principles  of  organized  bodies 
is  intermediate  between  mere  organic  chemistry  on  the  one  hand, 
and  histology  on  the  other,  and  must  precede  the  latter. 

CLASSIFICATION   OF   THE   IMMEDIATE   PRINCIPLES   IN   THE 
HUMAN  BODY. 

The  number^  of  immediate  principles  in  the  human  body  is  not 
precisely  determined;  but  the  following  classification,  embracing 
81,  may  be  for  the  present  adopted. 

These  84  substances,  being  all  compound  except  oxygen,  hydro- 
gen, and  nitrogen,  are  divided  into  two  groups: — 

I.  The  first  group  includes  those  principles  which  are  crystal- 
lizahle  or  volatile^  without  decomposition.  These  are  di- 
vided into  two  classes : — 

1st.  Principles  of  mwera?  origin,  24  in  number. 
2d.  Principles  formed  within  the  body  by  dis-assimila- 
tion,^  and  therefore  of  organic  origin,  42  in  number. 
II.  The  second  group  includes  those  which  are  not  crystaUiza- 
hle^  or  not  volatile,  except  in  consequence  of  decomposition ; 
only  18  in  number.     This  group  is  not  divided,  and  con- 
stitutes the  third  class,  organic  substances. 
The  three  classes  are  divided  as  follows : — 

A.  Of  the  Jirst  class — principles  of  mineral  origin — there  are 

two  divisions, 

1st.   Gaseous  or  liquid,  and  not  saline  bodies,  5  in  number. 
2d.  Saline  bodies  (salts),  19  in  number. 

B.  The  second  class — principles  of  organic  origin — has  four 

divisions : — 

1st.  Acid  or  saline  principles,  23  in  number. 

2d.  Neutral  uitrogenized  compounds,  generally  called 

nitrogenized  alkaloids,  4  in  number. 
8d.  Neutral  720?i-nitrogenized  compounds  or  sugars,  2  in 

number. 


'  Recherches  Cliimiques  sur  les  coqis  gras  d'origine  animale.    Paris,  1823,  p.  4^5. 
^  Robin  and  Verdeil  reckon  92  immediate  principles  in  man  and  the  mammiferce. 
'^  This  word  implies  the  same  as  the  terms  "  waste"  or  "  metamori^hosis"  of  the 
tissues. 


40 


IMMEDIATE   PRINCIPLES   OF   THE   TISSUES. 


4th.  Fatty  and  saponaceous  compounds,  13  in  number. 
C.  The  //»Vf/ class — organic  substances — has  three  divisions: — 
1st.  Substances  naturally  in  a  liquid  state  (7). 
2d.  Those  naturally  solid  or  demisolid  (7). 
3d.  Pigmentary  substances,  also  solid  or  demisolid  (-4). 

The  following  table  indicates  the  particular  compounds  included 
in  each  of  the  classes  and  divisions  just  mentioned. 


Tabular  Classification  of  the  Immediate  Principles. 

Group  I. — Principles  crystallizable  or  volatile,  independ- 
ently OF  decomposition. 

First  Class.— PRINCIPLES  OF  MINERAL  ORIGIN  (24). 
First  Division.     Gaseous  and  not  Saline  (5). 


Oxygen, 

Hydrogen, 

Nitrogen, 

Second  Division. 
Chloride  of  Sodium, 

"  Potassium, 

Fluoride  of  Calcium, 
Hydroclilorate  of  Ammonia, 
Carbonate  of  Lime, 

"  Magnesia, 

"  Potassa, 

"  Soda, 

Bicarbonate     " 
Sulphate  of  Potassa, 


Carbonic  acid 
Water. 

Salts  (19). 
Sulphate  of  Soda, 
"  Lime, 

Basic  Phosphate  of  Lime  (Bones), 
Acid  Phosphate  " 

Phosphate  of  Magnesia, 
Neutral  Phosphate  of  Soda, 
Acid  "  " 

Phosphate  of  Potassa, 
Ammonio-Magnesian  Phosphate. 


Second  Class.— PRINCIPLES  OF  ORGANIC  ORIGIN  FORMED  WITHIN  THE 

BODY  BY  DIS-ASSIMILATION  (42). 

First  Division.     Acid  ok  Saline  Pkinciples  (23). 


Lactic  Acid, 

Lactate  of  Soda, 
"  Potassa, 

"  Lime, 

Oxalate  of  Lime, 

Uric  Acid, 

Neutral  Urate  of  Soda, 

Acid  "  " 

Urate  of  Potassa, 
"  Magnesia, 

"  Lime, 

"  Ammonia, 


Ilippuric  Acid, 

Hippurate  of  Lime, 
"  Soda, 

"  Potassa, 

Inosate  of  Potassa, 

Pneumic  Acid, 

Pncumate  of  Soda, 

Taurocholate     " 

Ilyocholinate    " 

Glycocholate     " 

Lithofellic  Acid. 


TABULAR   CLASSIFICATION.  41 

Second  Division.     Nkctral  Nitrooe.vized  Compounes  (5). 
(Nitrogenized  Alkaloids.) 
Creatine,  Urea  (and  Chloro-sodate  of  Urea — 

Creatinine,  Urea  with  marine  salt). 

Cystine. 

Third  Division,     Neutral  Non-nitrogexized  Compounds.     Sugars  (2). 
Sugar  from  tlie  Liver,  Sugar  of  Milk. 

Fourth  Division.    Fatty  and  Saponaceous  Compounds  (13). 

Cholesterine,  Caproate  of  Potass.,  Soda,  &c.. 

Oleic  Acid,  Oleine, 

Margaric  Acid,  Margarine, 

Stearic        "  Stearine, 

Oleate  of  Soda,  Elaterine, 

Margarate    "  Stearerine. 
Stearate       " 

GrOUJ)   II. — PeIXCIPLES   NOX-CRYSTALLIZABLE   OR   NOX-VOLATILE, 
IXDEPENDEXTLY  OF  DECOMPOSITION. 

Third  Class.— ORGANIC  SUBSTANCES,  OR  COAGULABLE  PRINCIPLES  (18). 
First  Division.     Those  naturally  Ltquid  (7). 
Fibrine,  Pancreatine, 

Albumen,  Mucosine, 

Albuminose,  Ptjaline. 

Caseine, 

Second  Division.  The  Solid  and  Demi-solid  (7). 
Globuline,  Cartilageine, 

Crystalline,  Osteine, 

Musculine,  Keratine. 

Elasticine, 

Third  Division.     Pigmentary  Substances  (4). 
Hfematine,  or  Hfematosine,  Melanine, 

Biliverdine,         '  Urrosacine. 

Ill  addition  to  the  preceding,  may  be  mentioned' — 

I.  Certain  immediate  principles  oi probable  or  certain  existence, 
though  not  well  determined. 

1.  Of  the  first  class — Silex,  in  hair,  &c.,  p.  37. 

2.  Of  the  second  class — Acetate  of  soda,  leucine,  xanthine,  h3'-po- 
xanthine,  lienine,  two  acids  peculiar  to  human  urine,  hasmatoidine, 
butyrine,  butyroline,  phosphorized  fatty  matters  of  the  brain,  cere- 
bric  acid,  and  cerebrate  of  soda. 

3.  Of  the  third  class,  the  following  are  probable  :  Neurine,  syno- 

'  Robin  and  Verdeil,  vol.  iii.  pp.  415  to  573. 


42  IMMEDIATE    PRIXCIPLES    OF   THE   TISSUES. 

vine,  lachrymiue,  spermatiue,  organic  substance  peculiar  to  dropsi- 
cal effusions,  paralbumine,  pyine. 

II.  Substances  known  to  exist,  but  doubtful  as  immediate 
principles. 

1.  Of  tlie  first  class;  amraonio-sodaic  phosphate;  phosphate  of 
ammonia  ;  ditto  of  iron  ;  chloride  of  calcium,  of  magnesium,  and  of 
iron  ;  arseniate  of  lime. 

2.  Of  the  second  class  ;  tartrate  of  iron  ;  benzoic  acid,  and  ben- 
zoates  of  soda,  potassa,  lime,  and  ammonia ;  glycocol ;  hippurate 
and  lactate  of  ammonia  ;  succinate  of  soda  ;  urostealite,  xanthocys- 
tine,  urate  of  iron,  sulphocyanuret  of  potassium,  and  of  sodium ; 
formic  acid ;  a  peculiar  crystallized  principle  in  semen ;  butyric 
acid ;  uroglaucine ;  inosite. 

3.  Of  the  third  class  ;  phymatine  ;  hydatidine;  animal  substance 
of  calculi ;  fibralbumine  ;  cyanurine;  melanurine  ;  coloring  matter 
of  blue  suppurations. 

III.  Certain  simple  bodies  whose  actual  state  of  combination  is 

unknown,  or  not  generally  indicated :  iron,  copper,  lead, 
manganese,  arsenic,  sulphur,  and  the  carbon  of  the  lungs. 
These  are  also  termed  medicinal  principles. 

IV.  Certain  natural  and  artificial  chemical  compounds  Avhich 

are  not  immediate  principles.     And 

V.  Substances  called  immediate  principles;  but  which  either 
do  not  exist  at  all,  or  do  so  as  mixtures  or  products  of 
chemical  chancces.^ 


First  Group. 
CLASS  FIRST. 

IMMEDIATE  PRINCIPLES  OF  MINERAL  ORIGIN". 

All  these  principles  have  a  definite  chemical  composition,  the 
formula  for  which  will  be  given  with  the  rapid  description  of  each 
of  them  which  follows. 

'  For  these  two  lists,  see  Am.  Metl.  Monthly  for  March,  1855. 


OXYGEN  —  HYDROGEN".  43 


FIRST     DIVISION, 


Tlie  gaseous  or  liquid  immediate  imnciples,  and  those  which  are  not 

saline. 

1.   Oxygen.  (0.) 

Oxygen  is  to  be  regarded  as  an  immediate  principle  only  when 
existing  in  a  free  state  in  the  body,  as  in  venous  and  arterial  blood, 
in  the  air-cells  and  bronchial  tubes,  and  sometimes  in  the  stomach. 

The  whole  amount  of  free  oxygen  in  the  bod}^  averages  about 
77^  grains,  and  in  the  blood  alone  61  grains.  There  are  about  9f 
cubic  inches  of  oxygen  in  the  arterial  blood,  and  14^i  inches  in  the 
venous.  But  the  proportional  amount  is  greater  in  the  former  than 
in  the  latter,  in  the  ratio  of  2.41  to  1,  and  sometimes  even  of  3  to 
1.17 ;  since  there  is  but  two-thirds  as  much  blood  in  the  arterial 
system  as  in  the  venous.  {Rohin  and  Verdeil.) 

Oxygen  exists  in  the  blood  in  a  liquid  state  (in  a  state  of  solution), 
and  probably  mostly  in  the  corpuscles  alone. 

The  amount  of  oxygen  received  into  the  lungs  of  an  inhabitant 
of  Potosi,  13,000  feet  above  the  level  of  the  sea,  however,  equals 
only  two-thirds  of  that  consumed  by  an  inhabitant  of  a  maritime 
city. 

The  theory  of  Liebig,  adopted  by  French  and  German  chemists 
generally,  that  in  the  case  of  the  higher  animals  the  oxygen  consumed 
in  respiration  is  destined  to  combine  finally  with  the  tissues  and  the 
calorific  (respiratory)  elements  of  the  food  (starch,  sugar,  fats,  &c.), 
thus  forming  carbonic  acid,  water,  &c.,/or  the  pwpose  of  producing 
and  maintaining  the  animal  heat,  is  evidently  too  narrow  a  view  of 
this  subject.  Heat  is  the  result  of  nutritive  changes  of  all  kinds, 
but  not  the  direct  object  of  them.  It  is  in  its  action  on  the  tissues 
of  the  body,  as  a  vital  stimulus,  that  the  prime  importance  of  oxy- 
gen consists;  though  the  incidental  development  of  heat,  as  above 
stated,  is  indispensable  to  the  organism. 

The  quantity  of  oxygen  consumed  in  a  year  by  an  adult  male  is 
about  800  pounds. 

2,  Hydrogen.  (H.) 
Free  hj^drogen  exists  normally  in  the  stomach,  colon,  and  ca?cum, 
forming,  of  all  the  contained  gases,  3.55  per  cent,  in  the  first  organ, 
from  5.4  to  11.6  per  cent,  in  the  colon,  and  7.5  in  the  ca3cum.    This 


4-i  IMMEDIATE   PEIXCIPLES   OF   THE   TISSUES. 

gas  is  formed  in  the  alimentary  canal ;  but  precisely  how,  is  not 
ascertained.  There  is  also  a  very  small  quantity  of  it  in  the  gases 
expired  in  normal  respiration.  None  has,  however,  yet  been  found 
in  the  blood,  though  the  last  fact  might  lead  us  to  expect  to  find 
it  there,' 

3,  Nllrorjen.  (N.) 
Free  nitrogen  is  found  in  the  air-cells  of  the  lungs,  in  the  blood, 
and  the  intestinal  gases,  both  healthy  and  morbid.  The  whole 
amount  in  the  lungs  and  the  blood  varies  from  -46,755  to  47.52 
grains.  In  the  blood  it  is  dissolved  and  in  a  fluid  state.  It  consti- 
tutes from  one-tenth  to  one-sixth  of  all  the  gases  in  this  fluid,  and 
is  more  abundant  in  the  arterial  than  in  the  venous  blood  (as  1.51 
to  1),  Animals  suffering  from  emaciation  inhale  more  nitrogen 
from  the  atmosphere  than  they  return  to  it  by  expiration, 

4.  Garlonk  Acid.  (CO.j) 
This  gas  exists  in  the  lungs,  the  alimentary  canal,  the  blood,  and 
the  urine,^  it  being  in  the  two  latter  in  a  state  of  solution.  The 
amount  in  the  blood  would,  in  its  gaseous  state,  occupy  from  one- 
fifth  to  one-third  of  the  space  actually  filled  by  the  whole  mass  of 
blood.  It  is  dissolved  in  both  the  serum  of  the  blood  and  the  cor- 
puscles, there  being  more  in  arterial  than  in  venous  blood  {E.  and 
v.),  as  is  the  case  with  oxygen  and  nitrogen.  Oxygen  is,  however, 
dissolved  principally  in  the  corpuscles,  as  has  been  seen.  The 
greater  amount  of  carbonic  acid  gas  in  the  arterial  blood  confirms 
the  idea  that  it  is  set  free  in  the  lungs  from  the  carbonates  in  the 
blood  by  the  action  upon  the  latter  of  pneumonic  acid.  [Rohin  and 
Verdeil.)     That  it  is  originally  formed,  however,  by  the  action  of 

'  Carhuretted  and  sulphuretted  hydrogen  are  also  included  among  the  immediate 
principles  by  Robin  and  Verdeil,  They  are  here  omitted,  since  they  are  found  only 
in  the  air-passages  and  the  large  intestine,  and  appear  to  be  evolved  in  consequence 
of  some  abnormal  chemical  process.  In  the  intestine  the  sulphuretted  hydrogen  is 
always  in  smaller  quantity  than  the  other  gases.  It  is  formed  in  the  alimentary 
canal ;  but  precisely  how,  is  not  ascertained.  It  is  also  disengaged  from  abscesses 
near  a  mucous  membrane  (e.  y.  near  the  anus),  or  by  putrefaction  of  pus  or  of  or- 
ganized tissue.  Abscesses  on  the  limbs,  under  the  deltoid,  or  iu  the  kidneys,  have 
also  been  known  to  disengage  it. 

2  "All  the  tissues  in  the  body  contain  a  small  quantity  of  dissolved  gases,  and 
carbonic  acid  can  be  detected  in  all  the  animal  fluids,  &c." — Todd  and  Bov:man, 
p.  730,  Am.  ed. 


WATER.  45 

oxygen  upon  tlie  tissues  and  tlie  calorific  elements  of  the  food,  may 
be  regarded  as  established;  and  to  prevent  an  undue  accumulation 
of  it  in  the  blood  from  these  sources  is  the  principal  object  of  the 
aerating  process, 

5.  Protoxide  of  Hydrogen — Water.  (HO.) 

Water  enters  into  the  composition  of  every  fluid  and  every 
tissue,  however  solid  (even  enamel),  in  the  body,  uniting  in  true 
binary  combination,  and  forming  one  of  its  essential  constituent 
parts.  It  is,  therefore,  one  of  the  most  important  of  the  immediate 
principles,  and  exists  in  far  greater  amount  than  all  the  rest  to- 
gether. 

The  cubical  mass  of  the  human  body  is  calculated  by  Eobin  and 
Verdeil  as  varying  from  62  to  70  litres^  in  the  male,  and  from  46  to 
53  in  the  female — equal  in  the  former  to  a  cube  16  to  16.4  inches  on 
a  side.  Of  the  preceding  quantity,  at  least  42  or  43  litres  are  water, 
which  equals  a  cubic  mass  14.1  to  15.2  inches  on  a  side.  Thus 
nearly  three-fourths  of  the  body  is  water.  Burdach  estimated  the 
water  at  two-thirds  of  its  weight.  Of  course  the  proportion  is  still 
greater  in  infancy  and  childhood, 

A  table  is  given  by  the  authors  just  mentioned,^  showing  the 
proportional  amount  of  water  in  each  fluid,  and  in  each  tissue  and 
organ,  in  the  body.  With  the  exception  of  enamel,  dried  cuticle, 
teeth,  bones,  tendons,  and  elastic  tissue,  there  is  no  tissue  which  is 
not  more  than  one-half  water.  Enamel  is  only  gi(j  water  (Senac); 
the  substance  of  the  testis,  y^oVo  water.  The  human  brain  is  iVo^j 
water.  {Denis.)  But  no  tissue  or  fluid  in  the  body  has  always  pre- 
cisely the  same  amount  of  water,  or  of  any  other  immediate  principle. 
It  varies  constautl}^,  though  within  narrow  limits,  from  one-tenth  to 
three-tenths,  and  the  mean  only  is  given  in  the  table  alluded  to. 

But  the  other  immediate  principles  vary  with  the  variations  in 
the  water.  Hence  the  error  of  those  Avho  would  find  the  cause  of 
diseases  in  one  tissue  or  fluid  alone,  or  Avho  would  cure  them  by  the 
administration  of  water  alone,  or  of  any  other  immediate  principle 
exclusively. 

In  all  the  tissues  and  organs  just  mentioned,  in  which  less  than 
one-half  is  water,  and  in  many  cases  where  the  water  constitutes 
•jYg  (muscle)  to  -^\%  (cortical  substance  of  calf's  brain)  of  the  whole, 

'  A  litre  is  very  nearly  a  quart  iu  measirre.  *  Op.  cit.,  pp.  115-llS, 


46  IMMEDIATE   PRINCIPLES   OF   THE   TISSUES. 

the  water  is  in  a  solid  state,  and  entirely  different  from  any  condition 
in  which  it  is  found  in  the  mineral  kingdom.  Hence  muscle  has 
more  consistence  than  blood,  and  the  cortical  substance  of  the  brain 
more  than  synovia;  though  these  two  fluids  have  less  water  than 
the  solids  compared  with  them.  This  water  is,  therefore,  in  chemical 
combination  in  the  tissues,  and  not  interposed  between  their  elements. 

In  the  fluids  the  water  is,  of  course,  in  a  f.uid  state,  and  here 
holds  solids  in  solution.  In  a  single  instance  only — the  halitus  from 
the  lungs — is  the  water  in  a  gaseous  state. 

Mere  solution  is  chemical  combination,  but  the  feeblest  known. 
Water  combining  with  a  solid  in  less  amount  than  suf&cient  to  dis- 
solve, is  fixed  in  it,  itself  becoming  solid ;  in  increased  quantity,  it 
dissolves  the  other  substance,  that,  on  the  other  hand,  becoming 
fluid.  The  organic  suhstances  (osteine,  musculine,  &c.)  have  the  pe- 
culiar property  of  fixing  an  amount  of  water  of  far  greater  volume 
and  weight  than  themselves,  while  they  still  remain,  and  also  render 
the  water  demi-solid.  Organs  formed  principally  of  these  substances, 
however  (and  hence  containing  much  water,  as  explained),  alone  live 
independently  and  on  their  own  account — alone  present  the  double 
vital  phenomenon  of  composition  and  decomposition. 

But  it  is  not,  however,  merely  pure  water — the  mere  protoxide 
of  hydrogen — that  is  fixed  and  solidified  by  albumen,  gelatine,  &c., 
but  a  saline  solution  instead.  Hence  they  swell  when  immersed  in 
pure  water,  since  an  additional  amount  of  the  latter  is  thus  gene- 
rally fixed. 

The  muscle  of  the  calf  contains  more  water  than  that  of  the  ox; 
but  an  equal  weight  of  human  bone  (separate  from  the  marrow), 
whether  from  the  infant  or  the  adult,  contains  the  same  amount 
of  it. 

Tables  are  given  of  the  diseases  in  which  the  blood  contains  an 
abnormal  amount  of  water,  whether  in  excess  or  diminution.  Since, 
however,  the  blood  is,  in  almost  all  cases,  taken  from  the  arm  alone, 
while  that  of  the  vena  portic,  of  the  hepatic  veins,  and  of  the  renal 
veins,  is  different,  and  cannot  be  examined  in  man,  wo  Tieed  further 
investigation  in  regard  to  the  blood  in  these  latter  vessels,  in  case  of 
diseased  animals,  that  we  may  thus  infer  its  condition  in  the  same 
vessels  in  cases  of  disease  in  the  human  body. 

Whence  comes  the  water  in  the  body? — for  it  both  enters  and 
leaves  the  body  already  formed,  /.  e.  as  protoxide  of  hydrogen. 
The  water  in  the  ovum  and  in  the  embrj^o  during  development  is 


SALTS.  47 

obtained  from  the  body  of  the  mother,  first  by  imbibition  from  the 
mucus  of  the  Fallopian  tube  by  the  vitelline  membrane,  then  by  the 
villi  of  the  chorion,  and  when  these  become  vascular,  after  the  de- 
velopment of  the  allantois,  they  derive  it  from  the  mother's  blood 
till  birth.  Subsequently  it  enters  the  blood  from  the  alimentary 
canal,  having  entered  the  latter  with  the  food,  or  ns  a  beverage; 
accidentally  entering,  also  (as  in  bathing),  by  the  skin.  The  aggre- 
gate amount  of  water  consumed  as  drink  by  an  adult  male  in  a  year 
is  about  1,500  pounds.  M,  Barral  finds  that  more  water  leaves  the 
body  than  enters  it,  and  maintains  that  the  surplus  is  foi^med  in  the 
body  by  the  combination  with  hydrogen  of  the  oxygen  in  the  in- 
spired air,  and  the  excess  of  oxygen  over  the  hydrogen  in  our  ali- 
ment. 

Uses  of  Water  in  the  Body. — It  gives  to  organic  substances  their 
mechanical  properties,  to  fluids  their  fluidity,  to  demi-solid  sub- 
stances their  elasticity  and  particular  consistence ;  and  different 
properties  to  the  hard  parts — to  cartilage  its  flexibility,  to  bone  its 
tenacity.  But  in  the  last  the  water  is  more  intimately  united,  and 
being  once  separated,  will  not  unite  again.  Water  gives  to  all  parts 
the  possibility  of  manifesting  their  chemical  properties  also,  and 
hence  that  instability  characteristic  of  organized  tissues,  and  the 
constant  acts  of  combination  and  decomposition.  But  it  also,  with 
these  advantages,  confers  the  liability  to  sudden  changes  in  the 
blood,  or  in  the  organs,  from  putrid,  purulent,  or  mephitic  infec- 
tions, facilitates  the  transmission  of  poisons,  procures  the  aptitude 
to  decomposition,  and  hence,  in  many  eases,  induces  sudden  death.' 

The  water  makes  its  exit  from  the  body  by  the  kidneys  and  the 
skin,  in  the  feces,  and  from  the  pulmonary  mucous  membrane. 
About  1,900  pounds  escape  annually  through  these  outlets,  the 
urine  alone  containing  900  pounds.  The  fact  that  400  pounds  more 
of  water  are  excreted  than  are  ingested  as  drink  is  accounted  for, 
in  part,  by  M. Barral,  as  already  stated;  while  it  must  be  recollected 
that  our  food,  also,  always  contains  more  or  less  water. 

SECOND  DIVISION. 

The  Scdlne  Princij^iles — Salts.  (19.) 

The  salts  contained  in  each  tissue  are  represented  by  the  ashes 
resulting  from  its  combustion  pretty  nearl}^,  but  not  precisely,  since 

'  Robin  and  Verdeil. 


48  IMMEDIATE   PRINCIPLES   OF   THE   TISSUES. 

the  carbonic  acid  of  the  carbonates  is  set  free  by  too  elevated  a  tem- 
perature, and  then  merely  the  base  remains  in  the  ashes.  Salts  enter 
into  the  composition  of  every  organized  tissue,  though  sometimes 
in  the  slightest  degree. 

The  salts  in  the  fluids  and  tissues  are  merely  dissolved  in  water; 
on  being  dissolved,  they  then  serve  as  solvents  for  other  immediate 
principles — e.  g.  solutions  of  salts  with  alkaline  bases  (soda  and 
potassa)  in  the  serum  of  the  blood,  dissolve  certain  fatty  principles 
there. 

None  of  the  salts  combine  with  the  principles  of  the  second  class 
(those  formed  by  dis-assimilation)  except  common  salt,  which  unites 
with  urea,  forming  the  chloro-sodate  of  urea.  It  is,  indeed,  in  this 
combination  with  soda  that  urea  exists  in  the  blood,  in  the  vitreous 
humor  of  the  eye,  and,  in  part,  also,  in  the  urine.  {R.  and  F.) 

Some  of  the  salts,  especially  several  of  the  phosphates,  in  con- 
nection with  water,  combine  directly  with  some  of  the  organic  sub- 
stances (third  class),  and  thus  result  certain  organized  substances, 
or  tissues.  E.g.  the  phosphate  of  lime  combines  directly  with  the 
osteine  in  bone,  to  form  the  tissue  of  the  latter. 

Besides,  the  earthy  salts  especially,  hy  their  imion  with  the  or- 
ganic substances,  manifest  a  power  in  aid  of  assimilation ;  and 
common  salt,  the  phosphates  of  lime  and  magnesia,  and  the  neutral 
phosphate  of  soda,  are  found  in  every  tissue  and  every  fluid  in  the 
body.  Hence  the  salts  are  indispensable  in  our  food.  They  also 
aid  in  dis-assimilation  by  yielding  their  bases,  while  still  forming  a 
part  of  the  tissues,  to  acids  of  organic  origin,  as  the  uric  and  hip- 
puric.  By  these  latter  combinations,  also,  the  animal  heat  is  in  part 
produced.  Moreover,  their  presence  with  the  principles  of  the 
second  class  alone  enables  several  of  the  latter  to  combine  with 
oxygen,  and  even  to  displace  it  from  metallic  oxides. 

Liebig  discovered,  in  respect  to  this  class,  that  the  phosphates  and 
carbonates  of  soda  may  replace  each  other  in  the  blood  without 
detriment.  Hence,  if  the  food  contains  only  phosphates,  without 
carbonates — e.g.  bread  and  meat — the  blood  contains  no  carbonates; 
if  potatoes  be  added  to  the  preceding,  the  blood  contains  some  car- 
bonates; and  if  the  diet  be  of  fruits  alone,  the  blood  acquires  the 
character  and  the  composition  of  that  of  the  ox  or  sheep.  The 
urine  also  contains  alkaline  phosphates  in  the  first  case,  and  alka- 
line carbonates  in  the  latter. 

The  observations  of  Bcncc  Jones,  to  the  cfioct  that,  in  cliorea  and 


CHLORIDE   OF   SODIUM.  49 

delirium  tremens,  the  sulphates  and  urea  are  increased  in  the  urine, 
while  the  phosphates  are  diminished,  and  that  in  encephalitis  the 
phosphates  and  the  sulphates  are  considerably  increased,  are  ex- 
plained by  a  reference  to  the  chemical  composition  of  the  muscles 
and  of  the  brain  respectively,  and  to  the  substances  resulting  from 
their  dis-assimilation. 

1,  Chloride  of  Sodium,  or  Marine  Salt.  (NaCl.) 
Common  salt  is  contained  in  every  fluid  and  every  solid  in  the 
body,  except  that  it  has  not  yet  been  found  in  enamel.  The  urine 
of  those  in  articulo-mortis  is  almost  entirely  deprived  of  it.  It  is  the 
most  abundant  of  the  principles  of  inorganic  origin,  and  is  found 
during  the  whole  period  of  existence,  even  in  the  ovule. 

Its  whole  amount  in  the  body  of  the  male  is  about  277.05  grs. 
"  "  "  female       "       234.9      " 

In  human  blood  the  marine  salt  amounts  to  0.31  to  0.37  per  cent., 
and  bears  to  all  the  other  salts  taken  together  the  proportion  of  2.4 
(even  3)  to  1 ;  and  the  proportion  is  very  similar  in  the  blood  of 
other  animals.  Muscular  tissue  contains  very  little  of  it,  and  Bra- 
connot  found  none  at  all  in  the  heart  of  the  ox.  There  is  more  of 
it  in  saliva,  gastric  juice,  mucus,  pus,  and  inflammatory  exudations,(?) 
than  in  the  blood.  Indeed,  it  always  abounds  where  cells  are  form- 
ing in  fluids. 

It  exists  in  a  liquid  state  in  every  part  except  the  bones,  teeth, 
and  cartilages.  It  is  always  dissolved  in  water,  and  never  chemi- 
cally combined  in  any  tissue  with  the  peculiar  elements  of  the  latter. 
Thus,  also,  it  is  never  found  in  the  organism  in  an  isolated  state. 

There  is  three  or  four  times  as  much  common 

"El"  1 

salt  in  the  blood  as  in  the  muscles,  and  still  more  ^.      *    * 

in  the  urine  than  in  the  blood.   The  proportion  ^^          °  ^ 

in  the  urine,  however,  varies  with  the  nature  of  ^  °       ^  %. 

the  aliment ;  that  in  the  blood  does  not.    There  ^  ^ 

is  a  large  amount  of  chloride  of  potassium  in  ^       /^  D 

the  muscles ;  and  this  salt  has  very  generally  ^    ^P    O  ^ 

been  confounded  with  the  chloride  of  sodium  chionde  of  sodium  ob- 

in  analyses  of  the  different  organs  and  tissues.  T:^,:U:^^ZZ 

The  forms  of  the  crystals  found  in  the  urine,  of  arifi.  and  siowiy  eraporat- 

common  salt,  are  represented  by  Figs.  1  and  2.  '°^' 

The  presence  of  common  salt  in  the  blood  is  a  condition  essential 
to  the  endosmosis  from  the  alimentary  canal  into  the  blood,  of  ali- 
4 


o 


50- 


IMMEDIATE   PRINCIPLES   OF  THE   TISSUES. 


mentary  substances  dissolved  in  water,  and  of  the  solution  of  albu- 
men, and  perhaps  of  the  fatty  principles.      In  connection   with 

albumen,  it  prevents  the 
solution  of  the  blood-cor- 
puscles in  the  serum.  It  is 
also  a  condition  of  the  acts 
of  assimilation  and  dis-assi- 
milation ;  hence  the  suppres- 
sion of  it  in  food  produces 
chlorosis  (even  in  man),  lan- 
guor, weakness,  and  pale- 
ness, and  even  oedema.  It 
produces  a  more  abundant 
secretion  both  of  saliva  and 
of  gastric  fluid,  and  thus  fa- 
cilitates digestion.  Hence 
it  is  needed  most  if  the  food 

Chloride  of  sodium  from   slow  evaporation   of  healthy      "^qq  principally  VeffCtable    Or 
urine.  .  /?  i        i  • 

in  case  oi  herbivorous  ani- 
mals, since  this  kind  of  food  contains  very  little  of  this  salt. 

More  marine  salt  than  is  actually  required  in  the  organism  enters 
the  stomach  in  the  food  and  drink.  The  average  daily  amount  con- 
sumed is,  according  to  M.  Barral,  4.75  grains  in  the  food,  and  109.2 
grains  added  as  condiment ;  more  than  this  amount,  however,  being 
used  in  the  latter  way  during  winter.  It  leaves  the  body  in  the 
urine,  the  feces,  the  sweat,  and  mucus. 

2.  Chloride  of  Potassium.  (KCl.) 

This  is  found  in  milk,  the  muscles,  the  liver,  cerebro-spinal  fluid, 
the  blood,  nasal  mucus,  saliva,  bile,  gastric  fluid,  and  the  urine.  It 
exists,  also,  in  the  fluid  rejected  in  choleras,  and  in  that  of  dropsies. 
In  the  preceding  alone  has  it  thus  far  been  found.  It  constitutes 
from  0.4  to  1  part  in  100  of  muscle,  and  only  .03  to  100  in  human 
milk.     In  blood  the  quantity  has  not  yet  been  specified. 

It  is  always  dissolved  in  water,  like  common  salt.  And  since  in 
human  blood  the  phosphate  of  potassa  is  always  accompanied  by 
chloride  of  sodium,  and  these  two  salts  may  become  mutually  de- 
composed into  chloride  of  potassium  and  phosphate  of  soda,  the  salt 
under  consideration  may  thus  be  formed  in  the  body,  as  well  as  be 
introduced  in  muscle  or  milk  used  as  food. 


CARBONATE   OF   LIME. 


51 


3.  Fluoride  of  Calcium.  (CaFl.) 
This  is  found  only  in  bones  and  teeth  (both  the  enamel  and  den- 
tine). Marchand  finds  1  per  cent,  of  it  in  human  bone;  the  quan- 
tity in  human  teeth  has  not  been  determined.  Berzelius  found  in 
the  ox  4  per  cent,  of  this  salt  in  the  enamel,  and  5  per  cent,  in  the 
dentine.  It  is  not  known  from  what  alimentary  substances  it  is 
derived,  how  it  leaves  the  body,  nor  the  part  it  acts  therein,  except 
by  reason  of  its  hardness.' 

4.  Hydrochlorate  {and  Carhonate  and  Bicarbonate)  of  Ammonia. 

(NH3HCI.) 
Nothing  is  known  of  the  functions  of  these,  and  it  is  not  demon- 
strated that  the  last  two  are  immediate  principles.     The  first  exists 
in  the  tears,  the  saliva,  and  the  urine.   Whether  formed  in  the  body, 
or  derived  from  the  food,  is  unknown. 

5.  Carhonate  {and  Bicarbonate)  of  Lime.  (CaOCOg.) 
The  presence  of  the  latter  is  only  accidental  in  the  human  body. 
The  carbonate  of  lime  exists  in  bones,  teeth,  cartilages,  and  the 
blood.  Otoconites  are  formed  almost  entirely  of  it.  Traces  are 
found  in  the  ashes  of  the  lungs.  It  is  also  found  in  the  concretions 
(incorrectly  called  ossifications)  of  the  muscles,  arteries,  valves  of 
the  heart,  in  false  membranes,  around  fibrous  tumors  of  the  uterus, 
in  the  dura  mater,  and  in  the  pineal  body.  Preputial,  salivary,  ton- 
sillary,  lachrymal,  and  certain  pulmonary  concretions,  tubercles  (cre- 
taceous and  the  common  form),  and  certain  urinary,  biliary,  and 
arthritic  calculi,  contain  this  salt.  In  all 
cases  it  is  combined  with  the  phosphate 
of  lime.  It  is  sometimes  also  found  in 
alkaline  human  urine.  A  rare  form  in 
the  urine  is  shown  by  Fig.  3 ;  it  usually 
being  an  amorphous  powder  like  the  phos- 
phate of  lime.  Landerer  has  also  found  it 
in  the  crystalline  lens  affected  with  cata- 
ract. 

This  salt  is  found  in  most  of  the  tissues 

.-.-,.  .  .A  rare  form  of  carbouate  of  lime, 

and  fluids  m  an  amorphous  state — e.  g.  m  found  in  aikaime  unue. 


'  Dr.  G.  Wilson  has  demonstrated  tlie  existence  oi  fluorine  in  the  blood  and  iti' 
milk ;  and  the  fluoride  of  calcium  exists  in  many  mineral  waters,  and  in  plants 
growing  in  micaceous  soils. 


52  IMMEDIATE   PRINCIPLES   OF  THE   TISSUES. 

the  pineal  gland,  on  the  plexus  choroides,  &c. ;  but  otoconites  are 
formed  entirely  of  carbonate  of  lime,  in  crystals  of  the  rhomboidal 
form,  which  is  peculiar  to  it. 

It  is,  doubtless,  in  a  solid  state  in  bones,  teeth,  and  cartilage,  and 
in  the  concretions  before  mentioned.  It  is  certainly  in  a  liquid  state 
in  the  blood,  but  not  in  direct  solution,  since  water  very  slightly 
dissolves  it.  The  chloride  of  potassium  and  the  carbonic  acid  there 
may  aid  in  its  solution,  since  both  the  former  and  also  a  fluid  con- 
taining the  latter  acid  dissolve  it  in  a  slight  degree.  In  bone  and 
cartilage  the  carbonate  is  doubtless  united  with  the  phosphate  of 
lime  before  being  combined  (in  company  with  it)  with  the  organic 
bases  (osteine  and  cartilageine)  to  form  the  fundamental  organized 
substance  of  these  two  tissues.  It  is  derived,  in  the  organism,  from 
spring  water  holding  carbonic  acid  in  solution,  and  also  from  the 
other  salts  of  lime  in  the  food. 

Finally,  much  of  the  carbonate  of  lime  found  by  calcination  of 
tissues,  &c.,  whence  it  is  derived,  may  be  formed  by  this  process 
itself;  since  all  the  salts  of  lime  which  have  a  combustible  acid  (e.  g. 
the  lactic)  are  thus  converted  into  the  carbonate  of  lime. 

6.  Carbonate  and  Bicarbonate  of  Soda.  (NaO.C02  &  Na0.2C02  +  HO.) 
The  first  of  these  salts  is  found  in  the  blood,  feces,  saliva ;  in  the 
urine,  when  alkaline,  without  being  ammoniacal ;  and  in  osteo-sar- 
coma.  Valentin  also  found  about  one-third  of  one  per  cent,  of  it 
in  the  compact  tissue  of  healthy  bone.  It  is  always,  in  the  organ- 
ism, dissolved  in  water,  and  therefore  liquid  or  solid,  as  may  be  the 
case  with  the  water  itself.  In  blood  it  constitutes  0.1628  per  cent., 
and  in  feces  .08  per  cent.  To  it  is  due  the  alkaline  reaction  of  the 
blood,  the  saliva,  and  the  cerebro-spinal  fluid.  It  is  combined  with, 
and  dissolves,  the  albumen  of  the  blood ;  and  even  prevents  the 
fibrin  from  coagulating,  if  the  blood  drawn  from  a.  vein  falls  into  a 
vessel  containing  a  solution  of  this  salt.  It  maintains  the  elasticity 
and  the  firmness  of  the  blood-globules,  conditions  without  which 
hsematosis  cannot  be  secured.  {Rohin  and  Verdeil.) 

A  very  little  of  this  salt  is  derived  from  water  and  food ;  it  is 
almost  wholly  formed  in  the  body.  The  malates,  citrates,  tartrates, 
and  lactates  of  soda  and  of  potassa,  contained  in  fruits  taken  as 
food,  are  all  converted  into  the  carbonate  of  these  two  salts  respect- 
ively, and  thus  appear  in  the  urine.  The  hydrogen  lost  by  these 
acids,  on  being  converted  into  the  carbonic,  is  said  to  have  been 


SULPHATES   OP   SODA   AND   POTASSA.  53 

withdrawn  by  combination  with  the  atmospheric  oxygen,  to  form 
water  and  produce  animal  heat ;  a  proposition,  however,  which  ad- 
mits of  doubt.  The  salt  leaves  the  body  in  the  urine,  and  a  portion 
is  also  decomposed  in  the  lungs,  by  the  pneumic  acid,  into  the  pneu- 
mate  of  soda. 

The  bicarbonate  of  soda  exists  nowhere  else  than  in  the  blood,  and 
there  its  existence  is  very  probable,  rather  than  demonstrated.  It 
is  formed  by  the  action  of  the  carbonic  acid  in  the  blood  upon  the 
carbonate  of  soda.  Its  function  is  too  nearly  identical  with  that  of 
the  latter  salt  to  need  further  notice  here. 

7.  Carbonate  {and  Bicarbonate)  of  Potassa.  (KOCO2.) 

The  latter  of  these  two  salts  is  found  in  the  urine  of  the  herbivora, 
but  not  in  the  human  body  at  all. 

The  carbonate  of  potassa  exists  in  the  blood  of  the  herbivora,  and 
of  man  and  the  dog,  when  they  consume  vegetable  food.  It  does 
not,  however,  in  the  former,  equal  more  than  one-third  or  one-half 
of  the  carbonate  of  soda.  It  is  formed,  like  the  latter  salt,  from  the 
malate,  citrate,  tartrate,  lactate,  &c.,  of  potassa.  Its  function  appears 
to  be  very  similar  to  that  of  carbonate  of  soda. 

8.  Sulphate  of  Soda.  (NaOSOg+lOHO.) 
This  principle  exists  in  very  small  quantity  in  the  body,  but  in 
almost  every  part  and  fluid,  except  the  milk,  bile,  and  gastric  fluid. 
It  may  be  found  in  milk  when  administered  medicinally.  Poggiale 
found  0.44  in  1,000  of  human  blood.  It  everywhere  exists  in  a 
fluid  state,  dissolved  in  water,  and  conduces  to  preserve  the  elasticity 
of  the  blood-corpuscles,  and  to  dissolve  and  keep  in  a  liquid  state 
the  fibrin  of  the  blood.  It  is  derived,  probably,  from  food  and 
drink,  and  is  evacuated  in  the  urine. 

This  sulphate,  and  that  of  potassa,  increase  in  the  urine  in  in- 
flammatory diseases,  while  both  diminish  in  chlorosis  and  chronic 
maladies. 

9.  Sulphate  of  Potassa  and  of  Lime.  (KOSO3  and  CaOSOg.) 
The  first  of  these  is  found  Avherever  the  sulphate  of  soda  is,  they 
being  both  dissolved  in  water,  and  mixed.     Simon  found  3  parts  in 
1,000  of  urine.     Its  functions  appear  to  be  like  those  of  the  pre- 
ceding salt. 

The  sulphate  of  lime  is  said  to  exist  in  the  feces,  in  blood,  and  ia 


64  IMMEDIATE   PRINCIPLES   OF   THE   TISSUES. 

rachitic  bones ;  but  this  is  not  yet  certain.  It  is  probably  held  in 
solution  by  the  alkaline  salts,  already  described.  It  is  obtained 
from  the  water  drunk.  It  is,  perhaps,  evacuated  in  small  quantity 
in  the  urine ;  or  is  decomposed  into  some  other  salt  of  lime,  and 
one  of  the  sulphates  just  mentioned. 

10.  Subphosphate  or  Basic  Phosphate  of  Lime. 
{Phosphate  of  Lime  of  the  Bones — SCaO.SPOj.)^ 
The  ashes  of  every  tissue  and  fluid  in  the  body  of  man  and  the 
mammiferas  contain  this  salt,  while  some  of  them  have  it  for  their 
principal  constituent,  so  far  as  the  mass  is  concerned.     It  consists 
of  eight  parts  of  the  base  combined  with  three  parts  of  the  acid. 
All  calcareous  deposits,  as  well  as  many  urinary  calculi,  and  phos- 
phatic  gravel,  contain  this  salt.    We  have  seen  that  in  all  cases  this 
exists  where  the  carbonate  of  lime  does.     It  is  the  phosphate  of 
lime  which  forms  most  of  the  calculi  around  foreign  bodies  intro- 
duced into  the  bladder,  and  those  of  the  prepuce,  and  which  is 
deposited  on  instruments  left  for  a  time  in  the  bladder.     It  forms, 
often  by  itself,  or  with  the  ammonio-magne- 
^^'    '  sian  phosphates,  the  urinary  sand;  and  pros- 

tatic calculi  are  formed  of  it  alone.  Uterine 
and  vaginal  concretions  consist  of  this,  with 
a  little  animal  matter  around  some  nucleus 
introduced  from  without.   A  calculus  of  this 

Phosphate  of  lime  calculus,from       gait  is  shoWU  by  Fig.  4. 

The  quantity  of  phosphate  of  lime  varies 
in  different  parts.  In  bones  there  is  48  to  59,  and  in  enamel  even 
88|,  per  cent.;  in  dry  muscular  fibre,  .93  to  1  per  cent.;  in  coagu- 
lated albumen  (from  the  blood),  1.8  per  cent.;  and  in  fibrine  (from 
venous  blood),  .69  per  cent.  It  is  also  a  constituent  of  caseine, 
globuline,  and  cartilageine ;  and  of  osteine  in  the  white  fibrous 
tissue,  as  well  as  in  bone.  In  the  ashes  of  urine  are  2.57  per  cent., 
and  of  solid  feces  12.78  per  cent.  But  the  more  a  part  is  submitted 
to  mechanical  influences,  the  more  phosphate  of  lime  is  deposited. 
Thus  there  is  more  in  the  bones  of  the  lower  than  the  upper  ex- 
tremities (in  the  same  weight),  and  less  than  in  either  in  the  more 
passive  ribs.  The  eburnation  of  bone  is  generally  said  to  be  an 
illustration  of  the  same  principle ;  though  Lehmann  found  less  than 
the  normal  amount  of  this  salt  in  this  condition.     But  when  this 

'  Heintz  finds  the  formula  to  be  3CaO,PO. 


PHOSPHATES   OF   LIME   AND   MAGNESIA. 


55 


Fig.  5. 


salt  increases  in  the  various  bones,  the  others,  except  the  phosphate 
of  magnesia,  diminish  in  proportion,  and  vice  versa ;  the  proportion 
of  the  principles  of  mineral  origin  remaining  constantly  the  same 
at  all  periods  of  life,  and  both  in  the  compact  and  the  cancellated 
tissue.  The  salt  just  excepted,  however,  increases  or  diminishes 
with  the  increase  or  diminution  of  the  phosphate  of  lime.  {R.and  V) 

This  salt  is  in  a  solid  state  in  bone,  teeth,  nails,  and  hair.  Though 
insoluble  in  water,  it  is  in  a  liquid  state  in  the  blood  and  all  the 
other  animal  fluids,  whether  in  its  free  state  or  combined  with  albu- 
minous matters.  When  free,  it  is  in  solution  by  the  aid  of  the  free 
carbonic  acid  in  the  blood,  of  the  bicarbonates,  or  by  the  chloride 
of  sodium. 

In  bone  it  is  combined  with  their  peculiar  organic  substance 
(osteine),  and  doubtless  with  the  other  earthy 
salts.  It  is  also  combined  with  albumen  and 
fibrine  in  the  blood,  as  has  been  seen.  In  the 
urine  it  is  held  in  solution  by  the  acid  phos- 
phate of  lime  and  of  soda,  and  the  other  salts 
of  these  two  bases ;  also  by  the  carbonic  acid 
in  the  urine.  Its  appearance  as  a  urinary  de- 
posit is  shown  by  Fig.  5. 

This  principle  gives  to  several  tissues  their 
physical  properties  of  resistance  and  solidity, 
upon  which  their  uses  principally  depend. 
This  is  most  apparent  in  the  osseous  tissue. 
Liebig  also  ascribes  to  it  the  insolubility  of  certain  tissues,  as  the 
muscular  and  the  areolar. 

It  is  derived  from  milk  and  other  animal,  and  still  more  from 
vegetable,  diet.  The  phosphate  of  lime  of  bones — i.  e.  the  basic 
phosphate — exists  in  nature.  It  is  evacuated  in  the  urine.  That 
in  the  feces  is  the  overplus  in  the  aliment  which  had  not  left  the 
alimentary  canal  by  absorption.  A  part  is,  however,  changed  into 
the  acid  phosphate  of  lime,  and  then  aids  in  the  decomposition  of 
the  tissues. 

The  acid  pJiosjyJiate  or  hijyhosjyhate  of  lime  exists  in  urine  (and  in 
gastric  juice?),  and  is  formed,  probably,  from  the  basic  phosphate. 


Phosphate  of  lime  in  amor- 
phous powder.  The  rosettes 
are  the  triple  phosphate. 


11.  The  Phosphate  of  Magnesia.  (MgOPO,.) 
This  is  found  in  all  the  tissues  and  fluids  in  the  bodies  of  the 
mammiferse,  but  in  all  cases  in  small  quantity.  It  is  more  abundant 
in  muscle,  however,  than  the  phosphate  of  lime. 


56  IMMEDIATE   PKINCIPLES   OF   THE   TISSUES. 

It  is  found,  in  a  crystallized  form,  in  the  pus  of  abscesses  of  dif- 
ferent organs,  in  the  serosity  of  ovarian  and  other  cysts,  in  that  of 
the  pus  of  the  pleura  and  peritoneum,  and  on  the  surface  of  carious 
and  necrosed  bones.  Ovarian  calculi  are  sometimes  composed 
mainly  of  it,  and  a  small  quantity,  at  least,  exists  in  all  urinary 
calculi. 

In  human  bone  it  constitutes  1.16  per  cent.;  in  that  of  the  herbi- 
vora  it  is  more  abundant  (2.05  per  cent,  in  the  ox).  In  the  varying 
physiological  and  pathological  conditions  it  increases  or  diminishes 
with  the  phosphate  of  lime.  Of  enamel  it  constitutes  1.5  per  cent.; 
of  dentine,  1  per  cent. ;  of  muscle,  .023  per  cent.  Cartilage  contains 
a  large  amount — even  6.9  per  cent.;  and  blood,  .137  per  cent.  Hu- 
man milk  contains  .05  per  cent. 

In  bone,  nails,  and  teeth  it  is  probably  in  a  solid  state,  and  com- 
bined (as  is  always  the  case)  with  the  phosphate  of  lime.  Though 
slightly  soluble,  it  is  doubtless  directly  dissolved  in  water.  In  bone, 
&c.,  these  two  salts,  first  united  together,  combine  with  the  plasma 
to  form  the  organic  principle,  or  osteine. 

It  is  obtained,  in  the  organism,  from  vegetable  food;  carnivorous 
animals  deriving  it  from  the  bones  of  the  herbivora.  It  is  excreted 
principally  in  the  urine ;  the  feces  also  containing  any  amount  not 
absorbed  from  the  food,  as  well  as  that  contained  in  the  intestinal 
and  pancreatic  fluids.  The  formation  in  the  organism  of  ammonia 
causes  a  part  of  this  salt  to  pass  into  the  state  of  ammonio-magne- 
sian  phosphate — as  in  the  feces,  in  cases  of  typhus  and  dysentery. 
The  function  of  the  phosphate  of  magnesia  in  aid  of  endosmosis, 
and  of  assimilation  and  c^is-assimilation,  may  be  associated  with  that 
of  phosphate  of  lime. 

12.  Ammonio-Magnesian  Pliosphate.  (MgO.NHO^.HO.POj.) 
This  is  formed,  as  just  explained,  in  the  feces  in  disease,  and  in 
the  urine  after  standing  twenty-four  hours  or  less;  and  sometimes 
when  first  excreted,  if  the  latter  is  alkaline.  It  may  form  in  any 
alkaline  fluid  containing  the  phosphate  of  magnesia.  It  is  found  in 
vesical  calculi,  gravel,  and  sand,  and  still  oftcner  in  renal  calculi ; 
and  in  intestinal,  salivary,  uterine,  and  biliary  calculi.  In  all  cal- 
culi it  is  habitually  united  to  the  phosphate  of  lime.  It  exists  in 
the  fluid  form  only  in  acid  urine,  being  but  slightly  soluble  in  warm 
water  and  in  solutions  of  other  salts.  A  prolonged  use  of  phosphate 
of  magnesia  (or  mineral  water  containing  it),  has  produced  a  vesical 
calculus,  and  in  one  instance  even  in  two  weeks. 


PIIOSPUATE    OF   SODA, 


67 


It  escapes  from  tlie  body  in  the  fluid  (or  feces)  in  which  it  is 
formed.  For  the  various  forms  of  its  crystals,  as  found  in  the  urine, 
consult  Fiss.  6  to  10. 


Fig.  6. 


Fig.  7. 


Crystals  of  ammonio-maguesian  (triple)  phosphate,  with        Stellate  crystals  of  triple  phosphate, 
mucous  corpuscles,  from  catarrh  of  the  bladder. 


Fig.  8 


Fig.  10. 


Foliaceous  crystals  of  triple 
phosphate 


Eosettes  of  triple  phosphate. 


Calculus  of  triple  phos- 
phate. 


18.  The  Neutral  and  Acid  Phosphates  of  Soda.  (Na0.2HO.P054-2HO.) 
The  neutral  phosphate  is  found  in  all  the  fluids  and  solids  in  the 
body.  Urine  normally  contains  both  it  and  the  acid  phosphate,  the 
former  constituting  2.41  parts  in  1,000.  (Simon.)  In  cartilage  it 
constitutes  .92,  and  in  woman's  milk  .04  per  1,000.  It  is  always, 
in  the  body,  in  a  state  of  solution  in  water ;  and  this  solution  be- 
comes a  solvent  of  the  insoluble  phosphates  and  the  nitrogenized 
substances.  Thus  it  has  properties  analogous  to  the  sulphate  of 
soda.  It  may  also  replace  the  carbonate  of  soda  in  the  blood,  and 
does  so  in  case  of  a  substitution  of  animal  for  vegetable  food. 
It  escapes  in  the  urine  and  the  feces,  but  in  the  former  is  con- 


58  IMMEDIATE   PRINCIPLES   OF  THE   TISSUES. 

verted  previously  into  the  acid  phospliate,  or  into  the  forms  of  phos- 
phate of  lime,  of  magnesia,  or  the  ammonio-magnesian  phosphate. 
The  acid  phosphate  of  soda  has  hitherto  been  found  only  in  the 
urine.  We  have  seen  how  it  may  be  formed  from  the  neutral  phos- 
phate ;  the  basic  phosphate  may  also  exist  in  the  economy,  and  be 
converted  by  the  union  of  carbonic  acid  into  the  neutral  phosphate 
and  carbonate  of  soda.  The  acidity  of  the  urine  is  probably  due 
to  this  salt.  There  is  no  free  acid  in  fresh  urine,  except  the  uric, 
and  this  in  very  small  quantity.  The  constantly  changing  reactions 
of  this  secretion  are  owing  to  the  instability  of  the  phosphate  of 
soda.  {Rohin  and  Yerdeil) 

14.  The  Phosphate  of  Potassa.  (KOPO^.) 
This  very  much  resembles,  in  all  its  relations,  the  salts  just  men- 
tioned. Like  the  chloride  of  potassium,  it  is  unfavorable  to  the 
exchange  of  oxygen  and  carbonic  acid,  since  it  destroys  the  con- 
sistence and  elasticity  of  the  blood-corpuscles,  and,  like  it,  is  also 
much  more  abundant  in  the  muscles  than  in  the  blood.  Precisely 
the  reverse  is  true  of  the  phosphate  of  soda.  In  the  muscles  of  the 
calf  it  is  more  than  four  times  as  abundant  as  all  the  other  phos- 
phates taken  together.  {Robin  and  Verdeil)  It  is  derived  from  vege- 
table aliments  mainly.  It  has  not  been  found  in  the  urine;  but,  as, 
if  meeting  the  chloride  of  sodium,  the  phosphate  of  soda  and  the 
chloride  of  potassium  will  be  formed,  it  probably  leaves  the  body 
in  the  form  of  these  two  salts. 

15.  Carbonate  of  Magnesia.  (MgOC02.) 
This  salt  exists  rarely  in  the  bones  and  in  concretions,  and  is 
therefore  included  by  Lehmann  among  the  accidental  mineral  con- 
stituents of  the  body.     It  is  often  quite  abundant  in  the  urine  of 
herbivorous  animals. 

CLASS  SECOND. 

IMMEDIATE  PRINCIPLES  OF  ORGANIC  ORIGIN,  FORMED  WITHIN  THE 
BODY  BY  DIS-ASSIMILATION. 

The  principles  of  this  class  are  sometimes  termed  "secondary 
organic  compounds."  They  all  have  a  definite  chemical  composi- 
tion, are  formed  within  organized  bodies,  vegetable  and  animal,  and 
exist  only  in  them.    Being,  however,  formed  (except  the  fatty  prin- 


PRINCIPLES   OF   ORGANIC   ORIGIN.  59 

ciples,  as  hereafter  explained)  by  dis-assimilation,  they  constitute  a 
part  of  the  organized  substance  of  the  body  only  in  an  accessory 
manner,  and  not  as  original  constituents  of  the  tissues.  Hence  they 
are  rejected  from  the  body  (except  fat)  almost  as  soon  as  formed, 
mostly  in  the  bile  and  urine.^  Their  accumulation,  indeed,  is  inju- 
rious, and,  as  in  the  case  of  urea  and  others,  may  prove  fatal.  Even 
fat,  accumulating  in  the  epithelial  cells  of  the  kidney  or  the  liver, 
and  in  other  cases  of  fatty  degeneration,  produces  death.  Very 
corpulent  persons  do  not  attain  to  an  advanced  age. 

These  principles  (except  the  fatty,  so  far  as  they  enter  into  the 
formation  of  adipose  tissue)  are  not  alimentary,  not  assimilable. 
Only  the  first  and  the  third  classes  are  so.  Hence  our  food  must 
contain  these  last,  while  it  does  not  contain  the  principles  under 
consideration.  The  fatty  compounds,  however,  are  required  in  the 
food  for  the  development  of  adipose  tissue ;  and  sugar  is  usually 
taken  in  the  food,  though  it  may  be  formed  in  the  body  from  starch, 
in  case  none  is  thus  taken.  But  no  tissue  is  nourished  by  it.  In 
any  tissue,  therefore,  except  the  adipose,  in  which  these  principles 
are  found  (as  lactic  acid,  creatine,  &c.,  in  muscle),  they  are  the  result 
of  the  waste  of  the  tissue  itself. 

Though  so  numerous  (forty-two  in  all),  the  principles  of  the 
second  class  constitute  a  much  smaller  part  of  the  body  than  those 
of  the  other  two  classes,  since  they  generally  exist  in  small  quanti- 
ties. Indeed,  about  two-thirds  of  them  all  are  contained  in  the  blood, 
and  the  urine  is  next  in  order  in  this  respect.  The  bile  contains 
several,  also,  which  the  urine  does  not. 

All  these  compounds  are  in  the  liquid  state  in  the  body,  except 
(sometimes)  stearine  and  margarine ;  and  perhaps  the  cholesterine 
of  the  brain.  Some  of  them  may,  however,  accidentally  become 
solid,  and  form  concretions,  as  uric  acid,  cystine,  &c.  Generally 
they  are  liquid  by  direct  solution  in  water.  Stearine  and  marga- 
rine, however,  when  liquid,  are  dissolved  in  oleine. 

But  nine  simple  elements  are  found  in  this  class — sodium,  potas- 
sium, calcium,  magnesium,  sulphur,  carbon,  oxygen,  hydrogen,  and 
nitrogen. 

Preparatory  to  their  exit  from  the  body,  these  principles  gene- 
rally pass  into  the  state  of  carbonates,  and  then  of  carbonic  acid ; 
or  are  rejected  in  the  urine,  either  unchanged  or  after  isomeric  cata- 

'  This  class,  therefore,  includes  all  the  "urinary  deposits,"  except  the  organized 
(as  mucus,  pus,  and  blood),  and  some  of  the  salts  just  mentioned. 


60  IMMEDIATE   PEINCIPLES   OF   THE   TISSUES. 

lysis.    Some  of  them,  however,  are  previously  converted  into  lactic, 
uric,  hippuric,  or  pneumic  acid. 

Since  the  tissues  are  formed  mainly  from  the  immediate  princi- 
ples of  the  third  class,  and  those  of  the  second  class  result  from  the 
waste  of  the  tissues,  it  follows  that  the  last-mentioned  principles 
represent  the  amount  of  chemical  elements  of  the  third  class  which 
have  ceased  to  be  a  part  of  the  living  organism.  Hence,  though 
very  important  to  the  physiologist,  they  need  not  occupy  much 
space  in  a  work  on  histology.  The  most  important  alone  will, 
therefore,  be  particularly  mentioned,  and  these  as  briefly  as  possible. 

FIRST   DIVISION. 
Acid  or  Saline  Immediate  Principles  of  Organic  Origin. 

For  the  twenty -three  compounds  in  this  division,  the  reader  is 
referred  to  the  table,  page  40.  They  are  found  in  a  notable  quan- 
tity only  in  the  excrementitious  fluids,  or  in  the  urine  alone,  or  in 
morbid  products,  except  the  inosate  of  potassa  and  the  lactic  and 
pneumic  acids.  Only  these  two  acids,  together  with  the  uric  and 
hippuric,  and  the  oxalate  of  lime,  will  be  here  described.^ 

1.  Lactic  Acid.  (C6H30,.HO.) 

In  its  most  concentrated  state,  lactic  acid  is  a  colorless,  inodorous, 
thick,  syrupy  fluid,  not  solidifiable  by  the  most  intense  cold.  It 
exists  in  sour  milk,  resulting  from  the  fermentation  of  its  sugar. 
In  the  human  body  it  is  always  found  in  the  urine  when  the  oxalate 
of  lime  is,  and  while  one  is  living  on  a  strictly  animal  diet;  as  it  is 
in  all  circumstances  in  the  urine  of  carnivorous  animals.  It  is  also 
abundant  in  the  "muscular  juice;"  so  much  so,  indeed,  as  to  be 
more  than  sufficient,  Liebig  asserts,  to  saturate  the  alkali  of  all  the 
alkaline  fluids  in  the  body.  Lehmann  has  also  found  that  lactic 
acid  and  the  lactates  exist  in  the  human  gastric  juice  and  in  the 
small  intestines. 

Origin. — The  lactic  acid  in  the  stomach  and  small  intestines  pro- 
ceeds partly  from  the  gastric  fluid,  and  partly  from  the  starch  and 
sugar  in  the  food,  by  fermentation.  It  enters  the  urine,  of  course, 
from  the  blood;  and  the  latter  from  the  alimentary  canal  on  the  one 
hand,  and  from  the  muscular  juice  on  the  other. 

'  Tlic  last  four  salts  of  soda  in  this  class  (see  the  table),  are  peculiar  to  the  bile. 


URIC   ACID. 


61 


Uses. — Lactic  acid  in  the  gastric  juice  (with  the  hydrochloric)  is 
essential  to  the  digestion  of  the  nitrogenized  elements  of  oar  food. 
Moreover,  as  the  alkaline  lactates  are  absorbed  into  the  blood,  they 
undergo  rapid  combustion  (being  thus  converted  into  alkaline  car- 
bonates), and  thus  become  the  most  efficient  supporters  of  animal 
heat.  The  lactic  acid  in  the  muscular  juice  is  doubtless  a  resultant 
of  the  use  and  cZ/s-assimilation  of  the  muscular  tissue.  Hence,  as 
Berzelius  asserted,  it  increases  in  proportion  to  the  extent  to  which 
they  have  been  exercised.  Liebig's  hypothesis,  that  an  electric  ten- 
sion inflaencing  the  function  of  the  muscles  is  established  by  the 
acid  muscular  juice  and  the  alkaline  blood  in  the  capillaries,  is 
simply  ingenious. 

The  lactates  of  soda,  potassa,  and  lime  are  also  among  the  imme- 
diate principles  of  this  class. 


2.   Uric  Acid.  (CpHNp^.HO.) 
Uric  acid  always  constitutes  about  1  part  in  1,000  of  the  urine  of 
healthy  men.   It  is  usually  far  less  abundant  in  carnivorous  animals. 


Fig.  11. 


Fig.  12. 


Uric  acid  crystals — artificial. 
Fig.  13. 


Uric  acid — rhombs. 


Fig.  14. 


Uric  acid — thicker  rhombs. 


Uric  acid — modified  rhombs. 


62 


IMMEDIATE    PRINCIPLES   OF   THE   TISSUES. 


Its  crystals  are  usually  tinged  with  a  yellowisli  hue  by  the  coloring 
matter  of  the  urine,  and  their  various  forms  are  represented  by 
Fiffs.  11  to  19. 


Fig.  15. 


Fig.  16. 


Uric  acid — rhombs  replaced  by  square  form. 


Uric  acid — liour-glass  crystals. 


More  uric  acid  is  found  in  the  urine  during  disturbed  digestion, 
the  urea  being  at  the  same  time  diminished.  {Lehmann.)    It  is  in- 


Fig.  17. 


Fig.  18. 


Uric  acid  from  uriue. 


Uric  acid  as  sometimes  found  crystallized  ou  a  hair. 


Fig.  19. 


creased  by  any  obstruction  of  the  circulation  producing  deficient 

aeration  of  the  blood;  hence  it  increases 
during  fever,  in  heart  diseases,  and  en- 
largements of  the  liver;  also  very  much 
in  acute  articular  rheumatism.  It  dimi- 
nishes, however,  in  gout. 

In  the  urine,  when  discharged,  it  nor- 
mally exists  in  combination  Avith  soda,  and 
is  found  in  its  free  state  an  hour  or  more 
afterwards.  In  some  pathological  states, 
however,  and  in  cases  especially  of  uric 

Uric  acid  crystallized  on  a  fihrin-  .  ,         ,       .  ,„.  „^  i     n-i\     -^  i 

ouB  cast  of  a  uriniferous  tube,      acid  calculus  (Figs.  20  aud  21),  it  may  be 


URIC   ACID. 


63 


found /ree  in  urine  just  discharged.  It  often  constitutes  the  nucleus 
of  the  various  forms  of  urinary  calculi.  (See  "Urinary  Concretions," 
Part  II.) 


Fig.  20. 


Fig.  21. 


Uric  acid  calculus. 


Uric  acid  calculus,  showing  internal  concentric 
layers. 


It  is  demonstrated  that  the  urinary  deposit  described  by  Dr. 
Golding  Bird  as  the  urate  of  ammonia  is  the  urate  of  soda.  (Fig. 


Fig.  22. 


Fig.  23. 


Urate  of  suda. 


Urate  of  soda  calculus. 


22.)  This  salt  normally  exists  in  the  urine,  forming,  when  abun- 
dant, the  "lateritious  sediment,"  or  the  "amorphous  yellow  and 
impalpable  sediment"  {Prout)  so  common  in  febrile  states.  It  also 
forms  calculi  (Fig.  23),  and  concretions  in  the  joints.  Indeed,  the 
urate  of  ammonia  (Fig.  24),  very  seldom  occurs  as  a  urinar}'-  de- 
posit. {Lehmann.) 


64 


IMMEDIATE   PRINCIPLES    OF   THE   TISSUES. 


Urate  of  ammonia. 


Fig-  24.  Uric  acid  also  exists  in  the  blood,  the 

precise  amount  being  not  yet  determined. 
It  is,  however,  always  increased  in  it  in 
acute  gout,  and  often  in  Bright's  disease. 
It  is  not  increased  in  acute  rheumatism. 
From  .004  to  .0175  per  cent,  has  been 
found  in  the  blood  of  gouty  patients. 
(  Garrod.) 

Origin. — Though  uric  acid  is  doubtless 
a  result  of  waste  of  the  tissues,  it  is  not 
certain  from  what  substance  nor  in  what 
locality  it  is  first  formed.  It  appears  to  stand  "one  degree  higher 
in  the  scale  of  the  descending  metamorphosis  of  matter  than  urea" 
{Lehmann) — i.  e.  it  is  converted  into  urea  (and  oxalic  acid)  by  a 
partial  oxidation.  Hence,  when  aeration,  and  consequently  oxy- 
genation, is  imperfect,  more  uric  acid  and  oxalate  of  lime,  and  less 
urea,  appear  in  the  urine. 

3.  Eiiiiiuric  Acid.  (CigHgNO^.HO.) 

Hippuric  (or  uro-benzoic)  acid  is  present  in  the  urine  during  the 

use  of  a  vegetable  or  a  mixed 
diet.  It  occurs  in  large  quan- 
tity in  acid  febrile  urine,  what- 
ever the  variety  of  febrile  ex- 
citement, and  in  diabetic  urine, 
(Fig.  25.) 

The  hippuric  has  no  ascer- 
tained relationship  to  the  uric 
acid,  nor  is  any  thing  certainly 
known  of  its  origin.  It  is 
doubtless  formed  from  the  effete 
tissues,  and  has  no  special  use  in 
the  organism.  The  hippurate 
of  lime,  soda,  and  potassa  are 

Crystals  of  hippuric  acid  from  hnraan  «iiiie.  alsO  immediate  principles. 


Fig.  25. 


4.  Oxalate  of  Lime.  (CaO.CjOa.) 
This  salt  is  frequently  present  in  very  small  amount  in  normal 
urine ;  much  increased,  it  indicates  a  pathological  condition.     The 
forms  of  its  crystals  are  indicated  by  Figs.  26  to  29. 


OXALATE   OF   LIME. 


65 


The  dumb-bell  crystals  of  oxalate  of  lime,  so  called,  are  probably 
the  oxaluret  of  lime — Figs.  30  and  31.  {Bird) 


Fig.  26. 


Fig.  27. 


Octohedral  crystals  of  oxalate  of  lime. 


Fig.  28. 


Oxalate  of  lime. 


Fig.  29, 


Oxalate  of  lime. 
Fig.  30. 


Oxalate  of  lime — octohedral  crystals,  dried. 


Fig.  31. 


Oxaluret  of  lime — dumb-bell  crystals.  Oxaluret  of  lime — dumb-bell  crystals. 

The  oxalate  of  lime  increases  in  the  urine  after  the  use  of  vege- 
table food ;  and  of  beer  which  contains  much  carbonic  acid  gas,  and 
the  alkaline  bicarbonates  and  vegetable  acid  salts.  It  often  appears 
in  the  urine  of  pregnant  women,  and  very  constantly  on  the  mucous 
membrane  of  the  pregnant  uterus.  Lehmann  finds  that  it  increases 
5 


66 


IMMEDIATE   PRINCIPLES    OF   THE   TISSUES. 


if  the  aerating  process  is  in  any  way  disturbed,  and  is  common  in 
pulmonary  emphysema  and  chronic  bronchial  catarrh,  and  in  con- 
valescence from  severe  diseases — as  typhus.  It  is  always  accompa- 
nied in  the  urine  by  lactic  acid. 

The  mulberry  calculus  (Figs.  32  and  33)  consists  mostly  of  the 
oxalate  of  lime,  and  the  latter  enters  in  small  quantity  into  almost 


Fig.  32. 


Fig.  33. 


Oxalate  of  lime  (mulberry)  calculus. 


Section  of  mulberry  calculus. 


Fig.  34. 


all  the  varieties  of  calculi.    It  often  forms  alternate  layers  with  uric 

acid  (Fig.  34),  a  fact  disproving  the  notion 
of  the  "uric  acid  diathesis." 

In  some  cases  of  gout,  the  oxalate  of 
lime  exists  in  the  blood.  {Oarrod) 

Origin. — Oxalic  acid  (C2O3)  in  the  organ- 
ism is  normally  converted  into  carbonic 
acid  by  oxidation — C^Og  becoming  CjO^, 
or  2(062).  ^^J  cause  preventing  this  ox- 
idation, therefore,  causes  an  accumulation 

Aiteruutiug  calculus  of  oxalate  of  ^f  oxalic  acid,  which,  combiuiug  with  lime, 

limo  and  uric  acid.  '  '  "  ' 

forms  the  salt  under  consideration.  Oxa- 
late of  lime,  therefore,  proceeds — 1.  From  the  oxalate  in  vegetable 
food.  2.  It  accumulates  if  there  be  an  excess  of  carbonic  acid  gas 
in  the  organism  (as  from  beer,  &c.).  3.  Impeded  aeration,  producing 
diminished  oxidation,  may  increase  it;  and  hence  debility  of  the 
nervous  system  may  do  so  indirectly,  by  diminishing  the  respira- 
tory movements.  4.  Finally,  oxalic  acid  may  be  produced  by  the 
oxidation  of  uric  acid  and  several  other  substances  in  the  organism ; 
and  hence  diminished  oxidation  may  produce  more  uric  acid,  and 
less  oxalate  of  lime,  so  far  as  this  source  of  the  latter  is  concerned, 


CREATINE. 


67 


and  vice  versa.  Hence,  also,  alternate  layers  of  these  two  substances 
may  be  found  in  tlie  same  calculus,  and  the  idea  of  the  "oxalic 
diathesis"  must,  moreover,  be  regarded  as  a  fiction. 

5.  Pneumic  Acid. 

Pneumic  acid  was  discovered  by  Yerdeil  in  1851.  It  exists  in 
the  organized  substance  of  the  parenchyma  of  the  lung,  and  at  all 
ages  of  life.  It  has  the  same  relation  to  the  lungs  that  creatine  has 
to  muscle,  being  a  result,  probably,  of  their  metamorphosis.  It 
decomposes  the  carbonates  in  the  blood,  and  thus  sets  free  their 
carbonic  acid,  which  accounts  for  its  greater  proportional  amount 
in  arterial  than  in  venous  blood  (p.  44). 

The  pneumate  of  soda  is  also  found  in  the  lungs,  and  in  the  blood 
in  them;  but  it  subsequently  disappears,  not  being  found  in  any  of 
the  secretions. 


SECOND   DIVISION. 

Neutral  Nitrogenized  Immediate  Princi'ples.  (4.) 
1.   Creatine.  (C3H9N3O,.) 

Creatine  forms  transparent  and  very  brilliant  crystals  (Fig.  35), 
and  is  found  in  muscular  tissue  (both  the  striated  and  the  smooth 
fibre),  in  the  blood,  and  in  the  urine.   Lean  meat  contains  more  than 
fat  meat,  and  the  heart  most  of 
all.   It  constitutes  about  .067  per  ^^^"  ^^' 

cent,  of  human  muscle.  {iScJiloss- 
herger)  The  flesh  of  fowls  con- 
tains the  largest  quantity;  that 
of  fresh  water  fishes  the  smallest. 
It  is  always  in  a  liquid  state,  dis- 
solved in  water. 

Origin. — Creatine  in  the  mus- 
cular tissue  is  a  constituent  of 
the  "muscular  juice,"  hereafter  to 
be  described ;  but,  from  the  readi- 
ness with  which  it  is  decomposed 
into  creatinine  and  urea,  there  is 

■11         1        1  i.     ii      J.     •.      •  Creatine  crystallized  from  hot  water. 

no  reasonable  doubt  that  it  is 

derived  from  the  decomposition  of  the  muscular  tissue,  and  is  de- 


68 


IMMEDIATE    PRINCIPLES    OF    THE   TISSUES. 


Fig.  36. 


composed  into  these  and  similar  substances  in  the  living  body,  and 
thus  expelled  in  the  urine. 

2.  Creatinine.  (CgH^NaOj.) 
The  crystals  of  creatinine  are  shown  by  Fig.  36.     It  is  found 
only  in  the  muscles  and  the  urine,  and  always  in  company  with 

creatine.  The  liquor  amnii  also 
probahly  Goni2im.s  \i.  {Scherer)  In 
the  muscles  it  is  far  less  abun- 
dant than  creatine ;  in  the  urine 
it  is  far  more  so. 

Origin. — Creatinine  is  pretty 
certainly  produced  in  the  organ- 
ism from  creatine,  being  one  de- 
gree lower  than  the  latter  in  the 
descending  metamorphosis  of  the 
tissues.  It  differs  from  creatine 
merely  in  containing  two  equi- 
valents less  of  water,  or  is  crea- 

Creatiuine  crystallized  from  hot  water.  tiuC  miuUS  2(110). 

3.  Urea.  (C^H.Np^.) 
Urea  is  the  most  highly  nitrogenized  compound  in  the  body.    It 

crystallizes,   if  slowly,   in   flat, 
^^S-  ^"^^  colorless,  four-sided  prisms  (Fig. 

37);  if  rapidly,  in  white,  silky, 
glistening  needles.  It  is  found 
in  the  urine,  the  blood,  and  the 
vitreous  and  aqueous  humors  of 
the  eye.  It  exists  in  combina- 
tion with  common  salt  {i.  e.  as 
chloro-sodate  of  urea),  in  the 
blood  and  the  vitreous  humor, 
and  partly  so,  also,  in  the  urine. 
{Robin  and  Verdeil)  Urea  does 
not  exist  in  the  muscular  juice. 
[Grohe.)  It  sometimes  exists  in 
milk  {Bees),  and  very  often  in 

dropsical  transudations.     In  Bright's  disease  it  is  found  in  all  the 

serous  fluids,  and  sometimes  in  the  saliva. 


Urea  glowly  crystallized  from  aqueous  solution. 


SUGARS. 


69 


Urea  normally  constitutes  about  18  parts  in  1,000  of  urine. 
[Bird)  The  amount  is  increased  by  a  nitrogenized  diet,  and  by 
muscular  exercises. 

Origin. — It  is  decided  that  urea  is  formed  in  the  blood,  and  it  is 
doubtless  formed  from  creatine,  uric  acid,  and  probably  inosic  acid 
also,  by  the  action  of  the  alkalies,  and  of  free  oxygen.  {Lelimann) 
And  since  creatine  is  produced  by  the  waste  of  muscular  tissue, 
strong  muscular  exercise  increases  the  urea  in  the  urine.  Thus, 
also,  in  delirium  tremens,  and  all  states  attended  by  intense  muscu- 
lar actions  (convulsions,  &c.),  a  similar  increase  occurs. 

But  urea  probably  also  results  from  the  decomposition  of  any 
tissue  containing  nitrogen,  and  not  from  that  of  the  muscles  alone. 
Moreover,  if  an  excess  of  nitrogenized  food  is  absorbed  into  the 
blood,  it  is  excreted  in  the  form  of  urea,  this  substance  being  the 
last  and  lowest  step  in  the  descending  scale  of  the  metamorphosis 
of  the  tissues,  while  the  lactic,  uric,  and  oxalic  acids,  creatine,  and 
creatinine  constitute  the  preceding  grades.  The  idea  of  a  "urea 
diathesis"  is  thus  seen  to  be  un- 
tenable. Fig-  38. 


4.  Cystine.  (CgHgNO.S,.) 
Cystine  occurs  in  colorless, 
transparent,  hexagonal  plates 
and  prisms  (Fig.  38),  and  only 
in  the  urine,  and  in  pathological 
states.  It  is  richer  in  sulphur  (it 
constituting  25  per  cent.)  than 
any  other  organic  substance, 
except  taurine.  It  sometimes 
forms  calculi. 

Nothing  is  known  of  the  con- 
ditions of  the  formation  of  cys- 
tine in  the  oro;anism. 


Cystine  from  urinary  calculus,  recrystallized  from 
ammonia. 


THIRD    DIVISION. 


Sugars,  or  Neutral  Non-nitrogerdzed  Immediate  Principles. 

But  two  kinds  of  sugar  are  found  in  animals — sugar  of  the  liver, 
and  sugar  of  milk.  In  vegetables  there  are  several  kinds;  and 
grape  sugar,  or  glucose,  has  the  same  composition  as  hepatic  sugar. 


7t)  IMMEDIATE   PRINCIPLES    OF   THE   TISSUES. 

Hence  grape  sugar,  glucose,  hepatic  sugar,  and  diabetic  sugar,  are  all 
synonymous  terms,  and  are  all  expressed  by  the  formula  CjgHj^Oj^. 
Cane  sugar  is  Ci2HjjOji;  and  hence  grape  sugar  is  formed  in  the 
organism  (though  in  small  quantity)  from  the  latter,  by  the  addition 
of  three  atoms  of  water  3  (HO). 

Hepatic  sugar  (or  diabetic)  possesses  great  physiological  import- 
ance, and  is  an  immediate  principle  of  the  liver ;  and  milk  sugar  is 
normally  an  element  of  that  fluid.  That  either  results,  however, 
from  the  dis-assimilation  of  the  organ  producing  it,  is  scarcely  pro- 
bable, thovigh  they  are  included  in  this  class  by  Robin  and  Verdeil. 

1.  Hepatic  Sugar.  (CjjHj^Oij.) 
Synonyms :   Diabetic  Sugar  ;  Grape  Sugar ;  Glucose. 

Hepatic  sugar  exists  normally  in  the  parenchyma  of  the  liver,  in 
the  hepatic  veins,  and  the  portion  between  them  and  the  heart,  of 
the  inferior  vena  cava,  in  the  blood  of  the  right  heart  and  the  pul- 
monary artery.  During  fasting,  little  or  none  is  found  in  the  pul- 
monary veins,  the  left  heart,  and  the  aorta  and  its  branches ;  but 
during  digestion  it  may  be  found  in  all  these  parts,  in  small  amount, 
and  sometimes  in  the  veins  generally  also.  A  very  little  may  be 
found  in  the  vena  portoe  during  digestion,  but  never  at  any  other 
time,  unless  it  be  introduced  in  the  food ;  though  it  will  still  be 
found  in  the  hepatic  veins.  It  never  exists  in  bile,  in  the  normal 
state. 

It  is  found  from  the  fourth  or  fifth  month  of  intra-uterine  life  to 
the  most  advanced  age.  The  urine  of  the  foetus  in  utero  normally 
contains  it,  this  fluid  being  at  that  epoch  normally  diabetic. 

In  diahetes,  glucose  exists  in  the  urine,  the  kidney,  the  saliva,  the 
serosity  of  the  pericardium,  and  that  produced  by  a  blister,  in  the 
semen  (of  a  dog),  in  matters  vomited,  and  in  the  perspiration.  Others 
add  the  feces  also.^     But  none  is  found  in  the  brain  or  spinal  cord, 

'  Tlie  existence  of  the  yeast  fungus  (torula  cerevisi.'e)  in  urine  has  been  regarded 
as  a  proof  of  the  presence  and  the  fermentation  of  sugar.    (Fig.  39.)     Fungi  of  a 


Co        V 
Torula  corovisia;.     Successive  stages  of  cell-multiplication. 


HEPATIC   SUGAR.  71 

the  pancreas,  nor  the  spleen.  There  is  much  less  sugar  in  reptiles 
than  in  birds  and  mammals,  and  none  at  all  in  the  liver  of  the  ray. 

Glucose  exists  in  a  fl^iid  state  in  the  blood,  dissolved  directly  in 
water.  The  contact  of  organic  substances  in  that  fluid  rapidly  (in 
twenty-four  hours  or  less)  converts  it,  by  catalysis,  into  lactic  acid. 
In  the  urine  it  normally  combines  with  common  salt,  and  thus  loses 
the  taste  of  sugar.  In  the  liver  of  the  higher  animals  the  sweetish 
taste  is  owing  to  its  presence.  In  some  diseases  no  sugar  at  all  is 
formed  in  the  body  for  a  short  time  before  death.  An  excess  of  it 
is  one  of  the  signs  of  a  deep  general  lesion. 

Origin. — Normally,  the  grape  sugar  is  formed  in  the  liver,  from 
the  principles  of  the  organism  itself.  The  parenchyma,  and  the 
blood  in  the  hepatic  veins,  contain  it,  though  none  exist  in  the  food. 
{Bernard)  But  cane  sugar  also,  entering  the  vena  port?e  by  endos- 
mosis  from  the  intestines,  becomes  grape  sugar  in  the  hepatic  veins 
by  fixing  three  equivalents  of  water.  Perhaps  the  sugar  of  milk 
is  converted  in  a  similar  manner.  Glucose  itself  also  exists  in  some 
articles  of  food  (in  cooked  starchy  substances,  grapes,  &c.),  and  then, 
of  course,  appears  first  in  the  blood  of  the  vena  portee ;  though  most 
of  such  substances  pass  merely  into  the  state  of  dextrine  (CjaHjoOjo), 
and  which  probably  becomes  glucose  in  the  liver  by  assuming/owr 
equivalents  of  water. 

The  glucose  actually /or?)?  ec?  in  the  liver  (not  derived  from  food, 
&c.)  is  formed  in  its  parenchyma,  and  not  in  the  blood,  ^  since  in  ani- 
mals bled  to  death  it  still  remains  in  its  substance.  Anything  in- 
creasing the  activity  of  the  circulation  through  the  liver  increases 
the  quantity  of  sugar,  and  vice  versa.  Hence,  probably,  the  fact  that 
the  condition  of  the  nervous  system  modifies  the  amount  of  sugar 
(Bernard),  since  this  modifies  the  circulation.  Irritation  of  the  me- 
dulla oblongata,  at  the  origin  of  the  pneumogastric  nerve,  was, 
therefore,  found  by  Bernard  to  increase  the  quantity  of  sugar;  and 

precisely  similar  shape  may,  however,  be  developed  in  normal  nrine,  after  standing 
for  some  time  at  a  high  temperature,  and  sometimes  even  if  the  urine  still  pre- 
serves an  acid  reaction.  But  they  have  generally  only  about  one-half  the  diameter 
of  the  yeast-cells,  and  are  probably  developed  from  the  mucus.  For  an  illustration 
of  the  forms  of  vegetation  in  urine,  see  Figs.  127  and  128. 

'  Dr.  C.  Hanfield  Jones  has  recently  maintained  that  the  sugar  is  formed  by  the 
cells  of  the  liver,  while  the  bile  is  secreted  by  the  epithelial  cells  of  the  hepatic 
ducts  alone.  Neither  of  these  proportions,  however,  is  probably  correct.  See 
"  Liver,"  Cliap.  XIII. 


72  IMMEDIATE   PRINCIPLES   OF   THE   TISSUES. 

irritation  of  its  extremities  in  the  lung,  by  inhalations  of  ether  or 
chlorine,  produces  the  same  efiect,  by  a  reflex  action  to  the  liver. 
Hence  we  may  infer  that  in  diseases  of  the  lungs  or  medulla  ob- 
longata, diabetes  might  occur. 

The  changes  necessary  to  convert  the  cane  sugar  and  the  dextrine 
of  the  food  into  glucose  in  the  liver  have  already  been  stated. 
Moreover,  Bernard  has  shown  that  this  change  is  effected  by  the 
pancreatic  juice  in  the  duodenum.  But  all  thus  formed  passes  from 
the  vena  portte  into  the  hepatic  vein,  while  in  the  preceding  circum- 
stances it  is  formed  by  and  in  the  substance  of  the  liver  itself. 

The  glucose  disappears  from  the  blood  by  being  converted,  cata- 
lytically,  into  lactic  acid  (CgH^O^.HO),  which  decomposes  the  car- 
bonates, and  combines  with  their  bases  in  the  blood.  But  they  are 
soon  reconverted  into  carbonates,  and  in  this  form  are  evacuated  in 
the  urine.  If  there  be  an  excess  of  sugar  in  the  blood,  it  will  pass 
off  as  such  in  the  urine,  and  perhaps  also  appear  in  other  secretions 
already  specified. 

2.  Sugar  of  MUk.  (C,,H,,0,,.) 

Synonyms :  Lactine  ;  Lactose. 

This  is  found  only  in  milk,  and  in  that  of  all  the  mammalia.  It 
exists  only  from  some  point  of  time  after  puberty,  continues  only  a 
few  months  at  a  time,  and  ceases  a  few  months  after  the  last  preg- 
nancy. In  woman's  milk  it  forms  3.2  to  6.4  per  cent.;  the  colostrum 
containing  even  7  per  cent.  It  diminishes  in  quantity  the  further 
the  date  from  the  previous  delivery;  being  5.5  per  cent,  a  few  days 
after  delivery,  it  had  fallen  to  4.6  per  cent,  five  months  from  this 
time. 

It  becomes  glucose  (as  does  cane  sugar)  in  the  liver,  and  then  is 
finally  converted,  as  before  explained,  into  lactic  acid.^  If  this  latter 
change  occurs  in  the  milk  itself,  it  becomes  acid  spontaneously. 

Origin. — The  parenchyma  of  the  mammary  gland  fabricates  the 
lactine,  as  that  of  the  liver  does  the  glucose;  from  what  elements  is 
not  precisely  known.  The  longer  the  milk  remains  in  the  breast, 
the  less  sugar  and  other  solid  principles,  and  the  more  water,  it  con- 
tains. The  kidneys  and  the  lungs  are  merely  eliminators^  and  not 
fabricators. 

Taken  into  the  stomach  of  the  infant,  the  lactine  may  be  con- 

'  Four  atoms  of  lactic  acid  equal  one  of  lactine. 


FATTT  PKINCIPLES.  73 

verted  into  glucose  by  mere  addition  of  water,  or  by  the  action  of 
tbe  pancreatic  fluid  in  the  duodenum.  Or  if  not  thus,  this  con- 
version occurs  in  the  liver.  Its  subsequent  disposal  has  already 
been  explained. 

FOURTH    DIVISION. 

Fatly  Principles  [Fatty  Acids  and  Soaps). 

All  the  immediate  principles  of  this  class  exist  in  a  fluid  state, 
except  that  cholesterine,  margarine,  and  perhaps  stearine,  are  some- 
times, in  morbid  conditions,  found  solid.  They  are  also  composed 
of  carbon,  hydrogen,  and  oxygen  alone,  and  in  definite  proportions, 
and  are  found  in  both  vegetable  and  animal  organisms.  There  is, 
however,  no  proof  that  they  are  the  result  of  dis-assimilation,  though 
included  in  this  class  by  Robin  and  Verdeil. 

The  fatty  principles  exist  in  the  tissues  and  fluids  of  the  human 
body  in  three  entirely  different  conditions : — 

1.  Inclosed  in  cells,  which  constitute  the  fatty  or  adipose  tissue. 
This  will  be  described  in  connection  with  the  other  tissues. 

2.  They  exist  in  chemical  combination  with  other  elements,  and 
hence  can  be  detected  only  by  chemical  analysis.  This  is  the  case 
with  the  fat  in  the  organic  matter  of  epithelium,  nails,  horn,  and 
hair. 

3.  They  form  minute  oil-drops,  or  "fat-globules,"  without  any  en- 
velop, and  in  this  form  naturally  enter  into  almost  all  the  tissues, 
except  teeth  and  bones,^  and  into  many  of  the  fluids.  They  are 
very  minute,  though  of  varying  size,  and 

possess  a  high  refractive  power.   (Fig.  40.)  ^^'     ' 

Thus  the  fatty  principles  are  completely  iso-      g^^^=r.;j=s5y,--.t^-..^.^.>^^^ 

lated  from  all  others,  though  they  exist  with      ^-    -^    "   ^-  -t 

others  in  the  same  tissue  or  fluid.     These 

drops  are,  however,  themselves  always  made      > 

up  of  several  of  the  fatty  principles  united  , 

together,   molecule  to   molecule  ;    and   the 

same  is  true  of  the  fat  in  the  cells  of  adi-  Fat-ciobuies. 

pose  tissue.     The  only  exceptions  are  the 

fatty  elements  of  the  brain,  cholesterine  in  the  blood,  and  certain 

'  Bones  inclose  fat  in  their  cavities,  but  here  it  is  contained  in  cells. 


74  IMMEDIATE   PRINCIPLES    OF   THE    TISSUES. 

fatty  acids,  each  of  which  may  be  found  in  a  state  of  isolation  from 
other  fatty  elements. 

Though  several  of  the  tissues  contain  the  fat-globules  under  con- 
sideration, they  are  most  abundant  in  the  corpus  luteum.  They 
also  abound  in  cancerous  (encephaloid),  atheromatous,  and  other 
morbid  growths;  and  when  they  replace  the  normal  tissues  in  or- 
gans, or  become  abnormally  abundant  in  them,  they  produce  the 
"fatty  degeneration,"  or  Stearosis,  and  in  this  way  may  produce 
fatal  results.  The  organs  most  liable  to  this  change  will  be  speci- 
fied in  the  chapter  on  "Adipose  Tissue." 

The  fat-globules  exist  in  the  fluids  in  a  state  of  suspension  or 
emulsion.  The  smallest  of  all  are  those  of  the  chyle.  They  are 
twice  or  thrice  as  large  in  the  blood  during  digestion^  and  are  still 
larger  in  milk,  constituting  the  cream.  Fat-globules  also  normally 
exist  in  urine,  semen,  prostatic  fluid,  saliva,  nasal  mucus,  synovia, 
and  bile,  and  in  the  serosity  of  the  pleura,  of  the  peritoneum,  and 
that  produced  by  a  blister.  Blood-serum  contains  fat  even  when 
mixed  with  other  fluids  (as  urine),  and  pus  also  contains  it  in 
notable  amount. 

The  fatty  immediate  principles  exist  in  the  ovum,  and  through  life. 
In  the  adult  they  constitute  about  5  per  cent.,  or  o'o  of  the  weight 
of  the  body.  Of  the  entire  brain,  fat  constitutes  at  least  10  per  cent. ; 
of  the  muscles,  1 J  to  4  per  cent. ;  and  of  the  blood,  0.14  to  0.33 
per  cent.  The  globules  alone  of  the  blood  contain  0.331  per  cent. ; 
the  serum  alone,  0.175 ;  and  the  fibrine  (when  dry),  2.6  per  cent. 

Origin. — The  fatty  principles  in  the  body  are  mostly  taken  into 
the  organism,  already  formed,  in  the  food,  and,  being  converted  into 
an  emulsion  in  the  duodenum  and  jejunum  by  the  action  of  the 
pancreatic  fluid  {Bernard)^  are  then  absorbed  mainly  by  the  lacteals, 
and  enter  the  venous  current  from  the  thoracic  duct.  But  it  is  also 
extremely  probable  that  the  fatty  principles  may  be,  to  some  extent, 
formed  in  the  human  organism ;  and  Liebig's  idea  that  they  are 
formed  in  the  alimentary  canal,  from  the  metamorphosis  of  certain 
nitrogenized  elements  in  our  food,  is  the  most  plausible.  At  least, 
the  amount  of  fat  in  the  Mood  does  not  vary  much,  whether  the  food 
contains  very  much  fat,  or  is  deficient  in  it  (BoussingauU) ;  and  both 
the  amylaceous  and  the  nitrogenized  compounds  in  our  food  cer- 
tainly afford  the  elements  for  the  formation  of  the  fatty  principles. 
The  fact  sometimes  cited  to  prove  that  carnivorous  animals  form 
fat  within  their  own  or^ranisms — viz..  that  their  milk  contains  fat — 


CfrOLESTERINE. 


75 


proves  nothing,  since  most  of  the  tissues  of  the  animals  on  which 
they  prey  also  contain  it. 

It  is  also  very  certain  that  tlic  human  liver  has  the  power  ioform 
fat  directly,  to  some  extent,  as  well  as  sugar  (p.  71).  It  is  not, 
however,  probable  that  the  adipose  tissue  is  nourished  by  fat  formed 
elsewhere  in  the  organism,  but  that  the  fatty  materials  for  its  nutri- 
tion are  contained  in  the  food,  or,  in  default  thereof,  may  be  elabo- 
rated by  the  fat-cells  themselves  out  of  the  other  elements  brought 
to  them  in  the  blood.  But  that  almost  all  the  fatty  principles  in  the 
body  are,  under  all  ordinary  circumstances,  introduced  in  the  food, 
hardly  admits  of  a  reasonable  doubt. 

Of  the  fatty  principles  which  enter  the  blood,  a  portion  is  appro- 
priated to  the  nutrition  of  the  adipose  tissue,  and  others  norm.ally 
inclosing  "fat-globules,"  and  for  the  secretions  which  contain  the 
latter;  the  remainder  is  burned  up  by  combination  with  oxygen  to 
maintain  the  animal  heat,  and  leaves  the  body  in  the  form  of  car- 
bonic acid  and  water. 

Though  the  fatty  principles  possess  great  physiological  import- 
ance, only  oleine,  margarine,  and  stearine  are  especially  important 
to  the  histologist.  These,  therefore,  and  cholesterine,  will  alone  be 
here  considered.  "Seroline"  has  been  shown  by  Lehmann  to  con- 
sist of  the  crystallizable  parts  of  several  fats  blended  too-ether. 


1.   Cholesterine.  (Oj^Hj^O.) 
Cholesterine  (or  bile-fat)  crystallizes  in  very  thin  rhombic  tablets. 
(Fig.  41.)     It  is  normally  dissolved  in  the  bile,  and  is  found  in  the 


blood,  bile,  liver,  brain,  nerves, 
feces,  cerumen,  the  crystalline 
lens,  and  in  many  pathological 
productions.  Gall-stones  are 
composed  almost  entirely  of  it. 
The  blood  contains  about  .088 
parts  of  cholesterine  in  1,000. 
It  increases  in  old  a2;e,  and  in 
most  acute  diseases ;  especially 
in  inflammations,  and  in  icterus. 
It  also  occurs  in  pus,  and  often 
in  dropsical  transudations,  creta- 
ceous tubercles,  old  echinococ- 
cus  cysts,  encysted  tumors,  de- 


Fig.  41. 


Tablets  of  cholesterine. 


76  IMMEDIATE    PRINCIPLES    OF   THE   TISSUES. 

generated  ovaries  and  testes,  and  carcinomatous  growths.     It  has 
not,  thus  far,  been  found  in  the  urine. 

Cholesterine  is  found  only  in  animals,  and  must  be  formed  in  the 
organism — by  the  liver,  probably.  It  is  not,  however,  known  from 
what  elements  it  is  formed,  nor  what  of&ce  it  performs  in  the  organ- 
ism ;  nor  how  it  makes  its  exit  therefrom,  except  so  far  as  it  is  con- 
tained in  the  feces.  It  is,  however,  to  be  regarded  as  an  excre- 
mentitious  product,  and  probably  is  a  result  of  dis-assimilation  of 
the  liver  itself. 

2.  Oleine,  Margarine,  and  Stearine. 
These  three  immediate  principles  are  combined  together  to  form 
the  contents  of  the  cells  of  adipose  tissue,  and  the  fat-globules  in 
various  tissues  and  fluids.  Each  of  tliem  is  composed  of  a  fatty 
acid  in  combination  with  a  compound  radical — the  oxide  of  lipyl. 
(CgHgO.)     From  the  latter  glycerine  is  formed. 

1.  Oleine  {^3,^3fP>^  is  compounded  of  the  oxide  just  mentioned 
and  oleic  acid.  (C3gH3303.HO.)  It  is,  therefore,  the  oleate  of  the 
oxide  of  lipyl.  When  isolated,  it  maintains  its  fluidity  at  any  tem- 
perature above  zero  of  Fahrenheit,  and  in  it  are  the  margarine  and 
stearine  in  the  tissues,  dissolved. 

2.  Margarine  is  a  compound  of  margaric  acid  (C34H33O3.HO)  with 
the  oxide  of  lipyl,  or  is  a  margarate  of  this  oxide.  It  becomes 
solid  at  a  temperature  of  118°  Fahr.  It  forms  a  much  greater  pro- 
portion of  human  fat  than  oleine. 

3.  Stearine  exists  in  human  fat,  but  in  very  small  quantity.  It  is 
a  compound  of  stearic  acid  (Cg3H660j.2IIO)  and  the  oxide  of  lipyl, 
and  is  the  stearate  of  this  oxide.  Stearine  does  not  exist  in  vege- 
tables, but  is  the  main  constituent  of  all  solid  animal  fats,  as  sperma- 
ceti, suet,  and  tallow. 

Butter  contains  margarine  and  oleine,  but  no  stearine.  The  last 
may,  however,  be  formed  in  the  organism  from  the  other  two  prin- 
ciples. In  a  dog  taking  butter  alone  for  sixty-eight  days,  the  liver 
contained  a  large  quantity  of  stearine,  and  very  little  if  any  oleine. 
{Magendie)  It  will  be  seen  that  two  equivalents  of  margarine  pre- 
cisely correspond  to  one  of  stearine,  with  the  addition  of  one  atom 
of  oxygen.  These  three  principles  together  will  not,  however,  by 
themselves  nourish  an  animal,  while  adipose  tissue  will  do  so  for  a 
time. 

Soaps  are  formed  by  boiling  cither  margarine  or  oleine  with 


USES   OF   THE   FATTY   PRINCIPLES.  77 

potassa  or  soda.  Some  of  the  fatty  principles  are,  however,  not 
thus  decomposed  by  alkalies,  nor  by  the  oxide  of  lead,  and  are, 
therefore,  called  non-saponifiabJe  fats.  Cholesterine  and  seroline  are 
of  this  class. 

It  is  probable  that  potassa  decomposes  fat  in  the  body  as  well  as 
out  of  it ;  hence  the  liquor  potassEe  is  the  most  reliable  remedy  for 
excessive  corpulence.* 

Uees  of  the  Fatty  Princi'phs  in  the  Organism. — These  have  been 
generally  stated  on  a  previous  page  (p.  75).  Certain  further  par- 
ticulars should  find  a  place  here. 

1.  The  use  of  fat  in  the  adipose  tissue^  or  rather  of  adipose  tissue 
itself,  will  be  specified  further  on. 

2.  The  fat  in  the  hlood  is  partly  appropriated  to  the  nutrition  of 
the  adipose  tissue,  and  partly  appears  in  the  form  of  "oil-drops"  in 
the  tissues  and  in  several  secretions  (p.  76).  A  portion  also  enters 
into  organic  combination  in  the  structure  of  the  brain;  and,  finally, 
the  overplus  of  the  fat  is  burned  up,  and  thus  becomes  a  calorific 
material,  being  converted  into  carbonic  acid  gas  and  water,  and  thus 
leaving  the  body. 

But  it  is  also  quite  probable  that  the  bile  is  formed,  in  part  at 
least,  from  the  fat  in  the  blood.  Lehmann,  however,  considers  it 
doubtful  if  the  cholesterine  is  derived  from  this  source.  But  the 
blood  of  the  vena  portse  contains  more  fat  than  that  of  any  other 
bloodvessel  in  the  body ;  besides,  it  is  of  a  darker  brown  color,  con- 
tains more  oleine,  and  is  therefore  more  greasy  than  the  fat  in  other 
veins.  The  fact  that  there  is  much  less  fat  in  the  hepatic  veins 
points  to  the  inference  that  the  bile  is  formed  in  part  from  that  in 
the  vena  portse ;  and  this  is  confirmed  by  the  fact — first^  that  the 
secretion  of  bile  continues  free  during  starvation,  and  while  ema- 
ciation is  progressing ;  secondly^  that  the  blood  contains  more  fat  in 
icterus  than  in  any  other  disease ;  and,  thirdly^  that  a  disease  of  the 
liver  producing  diminished  secretion  of  bile  also  produces  obesity, 
as  that  occurring  in  drunkards  from  nutmeg  liver  and  other  diseases 
of  that  organ.  In  acute  diseases,  also,  emaciation  first  becomes  mani- 
fest in  connection  with  a  free  discharge  of  bile  from  the  alimentary 
canal,  {Lehmann?) 

Lehmann  expresses  the  opinion  that  fat  also  co-operates  in  the 
formation  of  the  blood-pigment,  or  hasmatine. 

'  See  the  chapter  ou  "Adipose  Tissue." 


78  IMMEDIATE    PRIXCIPLES   OF   THE   TISSUES. 

It  is  an  interesting  fact  that  in  tuberculosis  the  saponified  fats  are 
far  more  diminished  in  the  blood  than  in  any  other  fluid.  {Becquerel 
and  Rodier)  Solid  tubercle  itself  also  contains  but  little  fat ;  and 
it  is  not  an  unphilosophical  idea  that  the  principal  predisposing 
cause  of  tuberculosis  is  this  same  diminution  of  fat  in  the  blood, 
and  that  it  is  for  this  reason  that  fatty  compounds — and,  above  all, 
cod-liver  oil — are  found  so  efficient  to  prevent  or  arrest  it. 

3.  Why  fat  exists  in  some  of  the  secretions — as  semen,  mucus, 
&c. — is  not  understood.  Of  pus,  Guterbock  found  fat  sometimes  to 
constitute  even  5"  per  cent.;  about  3 J  per  cent,  being  contained  in 
the  corpuscles.  But  it  follows  that  an  excessive  secretion  of  these 
fluids  must  produce  emaciation,  as  results  from  profuse  suppuration 
and  from  venereal  excesses. 

The  fat  in  milk  is  essential  to  the  development  of  the  young 
mammal.  It  constitutes  2|  to  4  per  cent,  of  woman's  milk,  and 
exists  both  within  cefls  and  in  the  form  of  oil-drops.  In  the  colos- 
trum it  forms  the  peculiar  granular  cells,  or  "colostrum-corpuscles;" 
and  which,  being  also  seen  in  inflammatory  exudations,  in  the  sputa 
of  chronic  catarrh,  in  old  apoplectic  cysts,  &c.,  have  been  termed 
"glomeruli"  and  "inflammation-globules."  (Fig.  42.)     Not  a  single 

primordial    cell,   indeed,    can    be 
^'g-  '*2-  formed  in  the  embryo  without  fat 

^  '^mj'-  ''*  i^Sa^  ^)  ^i      ^^  ^"^^  *^^  ^^®  elements  of  its  com- 

^r^^"""    position.      Hence   plastic    exuda- 
"li^P^oo      tions,  also,   must   always  contain 

Glomeruli  and  granulous  cells;  the  darker  ones      fj^f    aud     itS    entire    abseUCC    WOuld 
beiug  the  glomeruli.  ' 

alone  render  an  exudation  uon- 
plastic.  In  inflammatory  exudations,  fat  is  usually  more  abundant 
than  in  the  liquor  sanguinis. 

4.  Fat  is  present  in  other  tissues  than  the  adipose,  in  the  form  of 
oil-drops,  mainly  for  a  mechanical  purpose,  it  would  seem ;  but 
when  it  becomes  excessive  in  amount,  a  pathological  state — stearo- 
sis — ensues. 

5.  The  uses  of  fat  in  the  food  are,  in  great  part,  to  be  directly 
inferred  from  the  preceding  remarks;  but  it  is  also  known  that  fat, 
in  combination  with  the  albuminous  elements  (albumen,  caseine, 
fibrine,  &c.)  of  our  food,  renders  the  latter  more  easy  of  digestion. 
{Lehmann  and  ElslLsser).  The  presence  of  fat  is  also  necessary  to 
enable  albuminous  matters  to  act  as  ferments.  [Lehmann)  Besides, 
fat  is  indispensable  for  the  original  development  of  all  the  tissues, 


EEMARKS.  79 

since  all  the  nuclei  of  tlic  primordial  cells  contain  fat-granules. 
Cell-growth,  therefore,  bears  some  proportion  to  the  amount  of  fat 
assimilated ;  and  even  pathological  formations  of  rapid  growth 
abound  both  in  cells  and  in  fat — e.  g.  encephaloid. 

Remarks. — 1.  From  the  fact  that  so  large  an  amount  of  fat — one- 
tenth  part — enters  into  the  composition  of  the  brain,  the  general 
emaciation  which  ensues  from  long-continued  intellectual  effort  may 
be  explained ;  for  fat  is  here  so  indispensable  that  the  nervous 
centre  will  draw  upon  the  other  tissues  and  organs  when  its  own 
supply  is  exhausted  ;  and  in  cases  of  fatal  emaciation,  death  always 
occurs  before  the  fat  is  notably  diminished  in  the  brain  and  the 
spinal  cord.  The  fact  that  excessive  activity  of  the  brain  also  pro- 
duces an  abundant  deposit  of  phosphates  in  the  urine,  is  explained 
by  the  cZzs-assimilation  of  the  phosphorus  which  so  abounds  in  that 
organ  (p.  36),  and  which  thus  passes  into  phosphoric  acid,  and  then 
unites  with  the  alkaline  and  earthy  bases. 

2.  Cod-liver  oil  is  a  kind  of  fat  which,  ^rsi!,  aids  in  the  digestion 
of  the  albuminous  elements  of  the  food ;  and,  secondly^  is  also  found 
experimentally  to  be  itself  easily  assimilated  in  parts  requiring  fat 
for  their  nutrition.  It  is,  therefore,  of  great  value  in  cases  of  actual 
or  threatened  emaciation,  from  any  cause.  Any  effect  of  this  sub- 
stance, further  than  that  of  protecting  the  various  organs  from  the 
impending  loss  of  their  fat,  and  thus  maintaining  the  strength  (by 
protecting  the  muscles,  especially),  is  merely  theoretical.  In  a 
word,  it  contributes  to  a  more  perfect  nutrition  in  the  two  ways 
just  explained,  and  thus,  in  case  of  prolonged  disease,  sustains  the 
strength  until  perhaps  the  morbid  process  exhausts  itself.  Thus  it 
acts  in  tuberculosis,  it  is  believed,  and  thus  alone.  Being  mere 
food,  therefore,  and  not  medicine,  it  should  be  given  with  other 
food,  as  a  general  rule,  and  not  between  the  meals,  as  is  often  re- 
commended. If  it  disagrees  with  the  stomach,  the  addition  of  an 
alkali  may  remove  this  objection,  it  probably  aiding  the  pancreatic 
fluid  in  converting  the  oil  into  an  emulsion  fit  for  absorption  by 
the  lacteals. 

If  it  be  inquired  why  other  oils  of  similar  composition  are  not 
equally  valuable  in  cases  in  which  this  succeeds,  it  can  only  be  re- 
plied that  the  fact  has  been  demonstrated  by  direct  experiment,  and 
experimentation  settles  everything  in  therapeutics.  But  there  is  no 
better  reason  for  adding  the  phosphate  of  lime  to  the  cod-liver  oil 
(a  fashionable  combination  of  late),  than  there  is  for  the  carbonate 


80  IMMEDIATE   PRINCIPLES   OF   THE   TISSUES. 

of  lime  and  other  salts  whicli  have  been  spoken  of  as  immediate 
principles;  unless  a  diminished  amount  of  the  phosphate  of  lime  is 
taken  in  the  food,  or  the  bones,  especially,  need  an  increased  amount 
of  it — as  in  rachitis  and  malacosteon. 


Second  Group. 

CLASS  THIRD. 
ORGAXIC  SUBSTANCES,  OR  COAGULABLE  PRINCIPLES. 

The  organic  immediate  principles  constitute  the  greater  part  of 
the  mass  of  the  organism;  those  of  the  first  class  entering  it  in 
smaller,  and  those  of  the  second  in  very  small  proportion.  These 
are  all  nitrogenized  compounds,  or  compounds  of  carbon,  hydrogen, 
oxygen,  and  nitrogen^  and  all  of  neutral  reaction. 

It  is,  however,  a  peculiarity  of  this  class  of  principles  that  they 
have  not  a  definite  chemical  composition,  as  is  the  case  with  the  other 
classes.  It  is,  indeed,  constantly  varying,  though  within  certain 
rather  narrow  limits,  the  variation  rarely  exceeding  1  per  cent,  in 
respect  to  either  of  the  chemical  elements  entering  into  their  com- 
position. It  follows,  of  course,  that  the  combinations  of  these  prin- 
ciples with  other  substances  (as  acids,  alkalies,  &c.)  cannot  be  definite 
and  uniform  compounds;  e.g.  sulphate  of  copper  and  albumen  being 
mixed,  the  salt  is  decomposed,  and  its  two  elements  combine  with 
the  albumen ;  yet  the  result  is  neither  sulphate  of  albumen,  nor 
albuminate  of  copper,  in  definite  proportions.^  (Robin  and  Verdeil) 

If,  therefore,  albumen,  fibrine,  &;c.,  are  constantly  varying  in  their 
own  precise  composition,  much  less  is  it  true  that  these  two  sub- 
stances are  always  identical  in  composition.  And  yet  two  analyses 
of  them  (e.  g.  of  fibrine)  may  not  be  more  nearly  identical  in  their 
results  than  an  analysis  of  the  former  as  compared  with  one  of  the 
latter. 

Most  of  the  earthy  salts — phosphates,  carbonates,  oxalates,  silex, 
and  the  silicates — unite  with  these  substances;  hence,  whenever 
concretions  are  formed  by  the  former,  a  certain  quantity  of  the 
organic  substances  is  fixed  and  retained  in  them.  This  union  is, 
however,  more  feeble  than  that  with  the  metallic  salts,  and  hence  is 

'  Hence  the  difficulty  of  distinguishing  these  principles  from  each  other  by  the 
reactions  of  mercury,  tin,  copper,  &c. 


ORGANIC   OK   COAGULABLE   PRINCIPLES.  81 

constantly  overcome  and  renewed  in  the  act  of  assimilation  and 
dis-assimilation.  It  is  from  the  more  intense  union  of  the  latter 
with  organic  matters  that  decomposition  after  death  is  prevented 
by  some  of  them,  since  thus  these  matters  are  hardened  and  con- 
tracted. Thus,  also,  these  salts  become  the  j^oisons  called  metallic, 
as  those  of  arsenic,  mercury,  &c. 

Some  of  these  principles  (albumen,  caseine,  and  fibrine)  are  in  a 
fluid  state  in  the  human  body;  the  rest  are  in  a  demi-solid  or  a 
solid  state.  All  these  may  be  reduced  to  a  more  solid  state  by  eva- 
poration of  the  water  which  forms  a  part  of  their  chemical  consti- 
tution, and  which  may  be  again  recombined  if  they  are  plunged 
into  this  fluid.  Meantime,  however,  the  tissues  containing  these 
substances  cease  to  perform  their  functions ;  and  if  too  long  dried, 
or  too  completely  so,  the  readdition  of  water  does  not  restore  the 
lost  power.  Thus  these  are  not  solid  substances  in  a  state  of  solu- 
tion, but  the  water  is  a  part  of  their  chemical  constitution. 

Coagulation  is  also  merely  the  passage  of  a  liquid  or  semi-liquid 
sv.bstance  into  a  solid  state,  and  not  the  return  of  a  substance  in 
solution  to  its  primitive  solid  state;  and  the  organic  substances 
alone  coagulate.  When  coagulated,  they  still  retain  their  ivater  of 
constitution,  still  united,  molecule  to  molecule,  in  the  organic  matter, 
as  before. 

The  materials  for  the  formation  of  these  principles  arrive  in  the 
organism  already  formed  in  the  food  (e.  g.  albumen,  fibrine,  &c.), 
whether  obtained  from  other  animals  or  from  vegetables;  and  which, 
undergoing  digestion,  affords  the  elements  for  their  formation  in  the 
human  body.  But  the  formation  occurs  in  the  organism  itself.  It 
has  been  suggested  that  those  principles  existing  in  the  blood,  espe- 
cially albumen  and  fibrine,  may  have  been  formed  from  the  same 
in  the  food,  from  the  occurrence  of  merely  isomeric  changes  in  the 
latter.  This  is,  however,  improbable,  so  far  as  the  fibrine  is  con- 
cerned, as  will  appear  in  a  subsequent  part  of  this  work. 

Though  these  principles  constitute  a  great  part  of  the  mass  of 
the  human  body,  the  iveight  of  other  principles  is,  in  certain  organs, 
greater  than  of  these;  e.g.  the  phosphate  of  lime  in  bones  and  teeth, 
as  compared  with  the  osteine. 

Of  the  organic  principles,  osteine  and  elasticine  are  not  found 
eai'ly  in  embryonic  life;  and  caseine,  being  an  element  of  milk,  is 
found  only  in  the  female,  and  after  puberty. 

It  is  probable  that  neither  of  these  principles  can  be  directly 
6 


82  IMMEDIATE   PRINCIPLES   OF   THE   TISSUES. 

transformed  in  the  organism  into  another,  except,  perhaps,  that  the 
albuminose  of  the  blood  may  be  transformed  into  albumen.  It 
appears,  however,  that  either  of  the  organic  principles  taken  in  our 
food,  and  subsequently  changed  by  the  digestive  process,  may  afford 
the  materials  out  of  which  the  same,  or  perhaps  several  others  of 
the  organic  substances,  may  be  formed  in  the  organism  by  the  assi- 
milative endowments  of  its  respective  parts  and  organs.  Still  less 
can  any  tissue  once  formed  be  directly  transformed  into  another,  as 
cartilage  into  bone,  &c.  Whenever  this  appears  to  be  the  case,  the 
former  tissue  is,  in  fact,  replaced  by  the  latter. 

All  these  substances  are  assimilable;  i.e.  they  do  not  appear  in 
the  urine^  if  admitted  into  the  blood  from  the  alimentar}^  canal  or 
otherwise,  in  proper  quantity,  but  disappear  entirely  from  the  blood, 
and  become  associated  with  the  tissues.  Even  the  organic  substance 
of  bone  (osteine),  so  long  as  it  is  associated  with  the  phosphate  of 
lime,  will  sustain  an  animal.  [Magendie)  The  fluid  obtained  by 
prolonged  boiling  of  bone  is,  however,  not  capable  of  sustaining 
animal  life  for  a  long  time,  for  thus  the  osteine  is  converted  into 
gelatine,  which  is  not  assimilated,  but  appears  in  the  urine. 

But  none  of  these  organic  substances,  taken  alone,  can  long  sus- 
tain life ;  the  principles  of  the  first  and  second  classes  must  be 
added,  as  mere  accessories,  but,  at  the  same  time,  indispensable.  In 
muscle,  for  instance,  the  musculine  is  united,  though  feebly,  with 
creatine  and  creatinine,  besides  the  water  and  the  salts.  Nor  can 
a/iiy  principle  alone  (not  even  the  organic  substances)  form  a  sub- 
stance manifesting  a  single  vital  property.  If  the  fibrine  of  the 
blood  sometimes  appears  to  do  so,  it  is  because  the  blood  contains 
the  principles  of  all  three  classes ;  for  fibrine  alone,  though  it  may 
form  a  false  membrane  (falsely  so  called),  can  never  become  vas- 
cular. 

Thus  we  must  distinguish  between  the  organic  principles  on  the 
one  hand,  and  the  anatomical,  or  rather  histological^  elements  of  the 
organism  on  the  other.  The  former  have  no  proper  form.  The 
latter  present  the  form  of  membrane,  fibres,  cells,  &c.,  and  are  never 
constituted  of  a  single  substance  alone.  The  simple  cell  or  mem- 
brane contains  principles  of  all  the  three  kinds,  water  always  exist- 
ing in  greater  or  less  abundance,  besides  salts  and  other  compounds. 

'  In  diseased  conditions  of  the  kidneys,  albumen  may  exist  in  the  urine,  as  all 
are  aware. 


ORGANIC   IMMEDIATE   PRINCIPLES.  83 

Chemistry  alone,  then,  does  not  give  a  just  idea  of  the  organic  sub- 
stances; their  examination  is  a  part  of  anatomy.  "It  is  not  carbon, 
hydrogen,  oxygen,  and  nitrogen  which  directly  form  the  organized 
substance,  but  bodies  composed  of  these,  which  act  directly,  and 
which  naturally  arrange  themselves  in  three  distinct  classes,"  {Ro- 
bin and  Vcrdeil.) 

The  organic  substances  leave  the  body  after  cZis-assimilation,  in 
the  form  of  lactic  and  uric  acid,  urea,  carbonic  acid,  water,  &c. 
Creatine  may  pass  into  creatinine,  and  subsequently  into  urea,  and 
then  appear  in  the  urine,  it  being  principally  derived  from  the  dis- 
assimilation  of  musculine.  Albumen  and  gelatine  may  also  pass 
into  leucine,  the  gelatine  being  derived  from  the  dis-assimilation  of 
the  osteine  in  bone  and  white  fibrous  tissue,  as  before  stated. 

Classification  of  the  Organic  Immediate  Princijjies. 

The  organic  substances  are  eighteen  in  number,  the  first  two 
divisions  of  them  constituting  the  "albuminous  compounds."  Al- 
bumen, caseine,  and  fibrine  have  recently  been  termed  the  "proteine 
compounds,"  since  a  compound  called  proteine,  and  represented  by 
the  formula  C3gH2jN40jo4- 2H0  {Mulder),  is  obtainable  from  them 
all,  and  which  has  been  assumed  to  be  their  compound  radical. 

Proteine  does  not,  however,  exist  in  nature.  It  is  obtained  only 
by  the  destructive  decomposition  of  these  substances,  and,  therefore, 
however  convenient  to  the  chemist,  it  has  no  interest  in  histology. 
Two  oxides  of  proteine  are  said  to  exist  in  the  blood — the  binoxide 
and  the  tritoxide;  the  latter  during  inflammations  more  especially. 
What  their  relations  to  the  tissues  are,  is,  however,  unknown. 

Nor  do  we  admit  the  "gelatinous  compounds"  hitherto  described.. 
Gelatine  (or  glutin)  and  chondrine  do  not  exist  naturally  in  the 
human  body,  but  are  formed  from  osteine  and  cartilageine  respect- 
ively, by  chemical  agency,  as  will  be  explained  in  the  description 
of  these  two  organic  substances. 

FIRST    DIVISION. 
Those  Naturally  in  a  Fluid  State. 
Of  these  seven  substances,  pancreatine,  mucosinc,  and  ptyaline 
have  no  special  importance  in  histology,  but  will  be  ao-ain  alluded 
to  in  the  part  describing  the  fluids  in  the  human  body. 
Pancreatine  is  found  only  in  the  pancreatic  fluid. 
Ptyaline  is  found  only  in  saliva. 


84  IMMEDIATE   PRIXCIPLES    OF   THE   TISSUES. 

Mucosine  is  found  in  mucus.  Three  kinds,  a,t  least,  may  be  speci- 
fied; and  Robin  and  Verdeil  mention  five.  1.  From  the  mucous 
membrane  of  the  nares  and  bronchial  tubes,  large  intestine,  and  the 
interior  of  the  uterus.  2.  From  the  neck  of  the  uterus.  8.  In  the 
urine. 

The  remaining  four  substances  are,  however,  of  paramount  im- 
portance in  histology,  and  will  be  particularly  considered.  They 
are  albumen,  caseine,  albuminose,  and  fibrine ;  the  first  three  of 
which  may  be  termed  the  "nitrogenized  histogenetic  substances." 
{Lelimann) 

1.  Albumen. 

Albumen  is  found  in  the  serum  of  the  blood  (seralbumen),  in  the 
chyle  and  lymph,  in  all  the  serous  secretions,  the  liquor  amnii,  and 
the  aqueous  and  vitreous  humor  of  the  eye.  Of  the  blood  it  consti- 
tutes 63  to  70  parts  in  1,000;  of  the  chyle,  30  to  60 ;  and  of  lymph, 
only  4.34  parts.  It  exists  in  the  blood  in  connection  with  soda, 
which  is  supposed  by  some  authors  to  keep  it  in  its  fluid  state.  The 
latter  is,  however,  the  natural  state  of  this  immediate  principle. 
{Rohm  and  Verdeil) 

Albumen  coagulates  at  a  temperature  of  145°  to  150°  (Fahren- 
heit). If  in  very  dilute  solution,  however,  a  boiling  heat  may  be 
reqiiired  to  solidify  it.  It  is  also  precipitated  from  a  solution,  in  a 
solid  form  by  the  tannic,  nitric,  and  all  the  mineral  acids,  except  the 
phosphoric.  The  last,  and  all  the  vegetable  acids,  except  the  tannic, 
even  dissolve  solid  albumen.  With  the  former  class  of  acids,  and 
with  metallic  oxides,  the  albumen  unites  as  a  base,  and  forms  a  ni- 
trate, tannate,  &c.,  of  albumen,  though  of  varying  composition. 

But  albumen  also  combines  Avith  alkalies  and  alkaline  carbonates 
as  an  acid ;  these  compounds  (albuminate  of  soda,  &c.)  being  soluble 
in  water.  The  neutral  albuminate  of  soda  exists  normally  in  the 
blood  of  the  hepatic  and  splenic  veins ;  the  basic  in  all  the  other 
vessels. 

With  most  of  the  metallic  salts  (acetate  and  other  salts  of  lead, 
the  salts  of  mercury,  &c.)  albumen  forms  insohihle  compounds. 

It  is  coagulated  by  the  ferrocyanidc  of  potassium,  by  alcohol,  and 
by  creasote.     The  last  acts  by  catalysis. 

Seralbumen  contains  2  per  cent,  of  phosphate  of  lime,  besides 
alkaline  and  earthy  sulphates  and  phosphates,  and  chloride  of  so- 
dium.    Ovalbumen  is  the  form  of  albumen  found  in  eggs.     Of  the 


ALBUMEN.  86 

white  of  eggs  it  constitutes  from  12.0  to  13.8  per  cent.     It  differs 
slightly  in  chemical  composition  from  seralbumen. 

Albumen  is  said  to  exist  in  a  solid  form  in  the  spinal  cord,  the 
brain,  the  nerves,  and  probably  in  several  other  organs  also ;  but, 
since  it  is  impossible  to  distinguish  coagulated  albumen  from  coagu- 
lated fibrine  in  the  tissues,  this  assertion  must  be  received  with  some 
reservations.  It  is  impossible  to  decide  whether  it  is  coagulated 
albumen  or  coagulated  fibrine  that  exists  in  tubercle  and  scirrhus. 
{Lehmann)  The  phosphate  of  lime  in  the  bones  is  generally  said 
to  be  obtained  from  the  albumen  of  the  blood-serum. 

As  albumen  has  not  a  definite  chemical  composition,  its  com- 
pounds necessarily  have  not.  It,  however,  combines  in  large  pro- 
portional amount  with  the  substances  previously  mentioned,  the 
combining  number  of  seralbumen  being  over  22.200.  {Mulder.) 
That  of  soda  is  only  31.3.  Seralbumen,  however,  differs  in  differ- 
ent persons.  Sulphur  and  phosphorus  are  always  found  in  connec- 
tion with  it. 

Origin  of  Albumen  in  the  Organism. — The  albumen  in  all  the 
tissues,  and  all  the  fluids  (except  chyle),  is,  of  course,  derived  from 
the  blood.  Most  of  that  in  the  blood  (except  what  enters  from  the 
lymph  and  chyle)  probably  enters  it  in  the  form  of  alhuminose  from 
the  alimentary  canal;  and  it  is  not  certain  that  it  can,-  in  entire  de- 
fault of  the  latter,  be  formed  at  all  in  the  organism  itself.  Such  a 
formation,  to  some  extent,  even  from  the  non-nitrogenized  elements 
of  the  food,  is  not,  however,  improbable. 

The  albuminose,  from  which  the  albumen  in  the  blood  is  directly 
formed,  is  produced  by  the  digestion  (principally  by  the  action  of 
the  pancreatic  fluid),  of  either  or  all  of  the  albuminous  immediate 
principles  in  the  food,  or  of  either  or  all  of  the  demi-solid  organic 
substances  next  to  be  considered  (musculine,  osteine,  &c.).  The 
albuminous  elements  of  food,  however,  which  are  now  under  con- 
sideration, may  be  derived  from  the  vegetable  or  the  animal  king- 
dom; the  demi-solid  immediate  principles  are,  of  course,  derived 
from  animal  food  alone. 

Uses  of  Albumen. — Albumen  exists  in  the  chyle  and  lymph,  as 
preparatory  to  entering  the  blood.  To  the  various  secretions  in 
which  it  normally  exists  it  imparts  a  certain  degree  of  lubricity. 
In  the  fluids  of  the  eye  it  becomes,  in  connection  with  other  imme- 
diate principles,  a  refracting  medium. 

Of  the  albumen  in  the  bloody  a  part  is,  of  course,  separated  in  the 


86  IMMEDIATE    PRINCIPLES   OF   THE   TISSUES. 

secretions  before  specified.  From  the  rest — and  this  is  its  most  im- 
portant use — the  various  tissues  are  mainly,  if  not  entirely,  deve- 
loped and  nourished.  It  is,  therefore,  emphatically  the  ^9a5i/?i/TO  of 
the  tissues,^  and  in  them  becomes  musculine,  osteine,  cartilageine, 
&c.,  as  it  is  assimilated,  in  the  process  of  nutrition,  to  the  peculiar 
organic  matter  of  muscle,  bone,  cartilage,  and  the  other  tissues. 
From  it,  also,  the  fibrine  of  the  blood  is  probably  formed. 

Albumen,  therefore,  leaves  the  organism — 1.  In  the  secretions 
specified.  2.  In  the  effete  matters  resulting  from  the  metamorphosis 
of  the  tissues  to  which  it  has  been  assimilated ;  e.  g.  in  the  form  of 
creatine,  creatinine,  urea,  uric  acid,  &c. 

Remar'ks. — 1.  Albumen  is  detected,  if  present,  in  urine  by  heat 
and  nitric  acid.  (See  fourth  paragraph,  p.  84.) 

2.  Styptics  act  by  coagulating  albumen — as  tannic  acid,  acetate 
of  lead,  sulphate  of  copper,  &c. ;  all  these  being  also  astringents. 
(§4.)  They^^rme  of  the  blood  coagulates  spontaneously  on  leaving 
the  vessels. 

3.  The  brain  and  spinal  cord  are  hardened  after  death,  by  alco- 
hol, creasote,  nitric  acid,  &c.  Hence  these  fluids  are  used  in  pre- 
serving anatomical  specimens,  (§  7,  p.  84.) 

4.  A  solution  of  acetate  of  lead,  applied  to  an  ulcer  of  the  cornea, 
may  produce  a  permanent  opacity.  (§  6.) 

5.  Albumen  is  an  antidote  to  corrosive  sublimate;  the  white  of 
one  egg  neutralizing  four  grains  of  this  poison. — Peschier.  (§  6.) 

6.  The  sulphur  combined  with  albumen  is  in  an  unoxidized 
state.  Hence  a  boiled  egg  blackens  silver,  a  sulphuret  of  silver 
being  formed.  Pus  often  blackens  a  silver  probe  for  a  similar 
reason. 

7.  Do  the  nitric  and  sulphuric  acids  check  the  discharges  in  diar- 
rhoea and  cholera,  by  coagulating  albumen? 

Pathological  Relations. — In  pathological  states  of  the  secreting  or- 
gans, albumen  may  exist  in  almost  any  secretion,  as  saliva,  gastric 
fluid,  bile,  mucus,  &c.  Mucous  membranes  may  appear  to  secrete 
albumen  in  addition  to  the  ordinary  mucous  corpuscles,  when  abnor- 
mally excited.  {Jul.  Vogel.)  But,  in  all  these  cases,  iransudatio)/,  in 
addition  to  secretion,  has  occurred.  Hence  the  presence  of  albumen 
in  a  fluid  resembling  pus  is  no  evidence  of  true  pus,  or  that  it  pro- 
ceeded from  a  granulating  surface. 

'  For  the  grounds  of  this  assertion,  see  chapter  on  the  "  Histological  Relations  of 
the  Blood." 


ALBUMINOSE.  87 

Albumen  may  appear  in  the  urine  in  a  variety  of  patbiological 
states,  thougli  formerly  supposed  to  be  pathognomonic  of  Bright's 
disease  of  the  kidney.  It  may  occur  in  acute  as  well  as  chronic 
affections  of  the  kidney.  It  also  not  seldom  appears  for  a  short 
time  in  many  acute  and  chronic  diseases  not  connected  with  renal 
affections,  as  "inflammations  of  the  thoracic  organs,  acute  articular 
rheumatism,  intermittent  fevers,  typhus,  measles,  cholera,  insuffi- 
ciency of  the  valves  or  contractions  of  the  orifices  of  the  heart;  also 
chronic  aiTcctions  of  the  liver,  and  pulmonary  and  peritoneal  tuber- 
culosis, especially  towards  their  fatal  termination.'"  It  also  occurs 
in  severe  catarrh  of  the  bladder,  and  in  the  renal  catarrh  supervening 
in  erysipelas  and  scarlatina,^  together  with  the  fibrinous  casts  of  the 
uriniferous  tubes,  such  as  appear  in  acute  nephritis. 

Albumen  exists  in  the  feces  in  diarrhoea  depending  on  intestinal 
catarrh,  and  in  cholera  and  dysentery.^  As  the  blood  becomes 
changed,  its  amount  increases ;  and  hence  this  symptom  occurs  in 
Bright's  disease  also,  and  large  patches  of  epithelium  may  be  dis- 
charged per  rectum. 

Albumen  is  an  element  of  pus,  constituting  from  6.85  to  8.36 
per  cent.  It  also  exists  in  all  exudations,  inflammatory  or  otherwise, 
and  in  all  transudations  (effusions),  whether  dropsical  or  not;  but  in 
the  latter  there  is  often  less  albumen,  and  always  more  salts  and  ex- 
tractive matters,  than  in  the  serum  of  the  blood. 

2.  Alhuminose. 

Albuminose  has  till  recently  been  confounded  with  albumen  and 
caseine.  MM.  Guillot  and  Leblanc  mistook  it  for  the  latter.  It  is 
liquid,  is  not  coagulable  by  heat,  and  incompletely  so  by  acids. 

Albuminose  is  found  in  the  blood,  constituting  4  to  6  parts  in 
1,000 ;  and  in  the  chyle  resulting  from  the  digestion  of  the  nitro- 
genized  (organic)  substances,  especially  albumen,  fibrine,  caseine, 
and  musculine.  It  is  formed  in  the  duodenum  and  jejunum,  from 
,the  principles  just  mentioned  in  the  food,  and  perhaps  by  mere 
isomeric  catalysis.  The  pancreatic  fluid,  however,  is  the  immediate 
agent  of  its  formation  thus.  {Bernard)  Unlike  albumen,  it  is  highly 
endosmotic,  and  is  not  united  with  salts  of  mineral  origin.''  En- 
tering the  blood  from  the  small  intestine,  it  then  mostly  becomes 
albumen,  or  may  probably  at  once  be  converted  into  musculine, 

'  Lehmann,  vol.  i.  p.  308.       '^  See  the  chapter  on  "Transudations."       '  Ibid. 

^  Mialhe  and  Pressat  mean  by  albuminose  the  "  endosmotic  and  assimilable  sub- 
stance finally  produced  by  the  action  of  gastric  juice  on  the  .albumen  of  the  food." 
(^Lehmann.) 


88  IMMEDIATE   PKINCIPLES   OF   THE   TISSUES. 

fi brine,  mucosine,  &c.,  in  tlie  solids  or  fluids  containing  these  sub- 
stances as  immediate  principles.  But  that  it  is  mostly  converted 
into  albumen  is  probable  from  the  fact  that  in  diseases,  if  very  little 
food  (or  none)  is  taken,  it  disappears  in  the  blood,  and  subsequently 
the  albumen  itself  also  diminishes.  It  was  this  in  the  fluid  dis- 
charged in  cholera  which  Giiterbock  mistook  for  caseine,  there  being 
also  very  little  albumen  in  choleric  discharges.  (Bohin  and  Verdeil) 

3.  Caseine. 

Caseine  is  found,  in  animals,  in  milk  only,'  constituting  2  to  4 
per  cent.,  increasing  as  lactation  proceeds,  and  being  more  abundant 
during  an  animal  than  a  vegetable  diet.  Its  properties  generally 
resemble  those  of  albumen ;  but  all  acids  (as  well  as  alcohol)  do 
coagulate  it,  while  heat  does  not. 

It  holds  even  more  phosphate  of  lime  (5  or  6  per  cent.)  in  solution 
than  albumen.  The  salts  are  merely  mixed,  and  are  partly  precipi- 
tated with  it  in  coagulating.  A  considerable  quantity  of  water 
mixed  with  it  is  also  set  free  by  its  coagulation. 

A  peculiar  property  of  caseine  is  its  coagulation  from  the  contact 
of  an  animal  membrane,  as  in  the  case  of  the  curd  (caseine)  in 
making  cheese.  Some  suppose  that  the  pepsine  in  the  rennet  (the 
dried  and  salted  digesting  or  fourth  stomach  of  the  calf\  coagulates 
the  caseine  by  catalysis,  since  the  rennet  will  produce  this  effect 
after  all  traces  of  acidity  (from  the  gastric  fluid  in  it)  have  disap- 
peared. Others  maintain  that  the  rennet  converts  the  sugar  of  milk 
into  lactic  acid,  which  uniting  with  the  alkali  holding  the  caseine 
in  solution,  the  latter  is  precipitated  in  the  solid  form.  But  caseine, 
like  albumen  and  fibrine,  is  naturally  fluid  {Bohin  and  Verdeil);  and 
Lehmann  remarks  that  the  true  cause  of  its  coagulation  is  still  un- 
known. The  acids  of  the  stomach  will,  however,  also  coagulate, 
caseine,  and  the  caseine  of  hnman  milk  is  not  precipitated  by  rennet 
without  the  assistance  of  acids. 

>  MM.  Guillot  and  Leblanc,  mistaking  albuminose  for  it,  have  announced  its 
presence  in  solution  in  the  blood  of  man,  woman,  and  several  of  the  lower  ani- 
mals, and  state  that  it  is  most  abundant  in  the  blood  of  women  just  before  delivery 
and  during  lactation.  Simon  observes  that  it  exists  in  the  })lood  of  lactating  wo- 
men if  the  secretion  of  milk  is  checked.  Panum  has  also  found  a  substance  in 
blood-serum  which  he  calls  serum-caseine.  It  is  extremely  probable  that  caseine 
does  exist  in  the  blood  of  women  during  lactation,  but  its  presence  there  cannot  be 
regarded  as  yet  demonstrated. 


FIBRINE.  89 

Origin. — Caseine  is  probably  formed  in  the  blood  (of  women) 
from  albuminose  and  albumen,  but  nothing  certain  is  known  on 
this  subject;  and  that  obtained  from  the  milk  of  different  animals 
8o  varies  in  its  properties,  that  Lehmann  suggests  that  "caseine  is 
not  a  simple  organic  body,  but  a  mixture  of  at  least  two  different 
substances.  It  is,  also,  a  highly  transmutable  substance,  often  un- 
dergoing change  on  the  application  of  the  mildest  reagents." 

Uses. — Caseine  exists  in  two  forms  in  milk:  1.  It  forms  the  in- 
vesting membrane'  of  the  milk-globules,  as  proved  by  Henle  and 
E.  Mitscherlich.     2.  Most  of  it  is  dissolved  in  this  fluid. 

Caseine,  taken  as  food,  probably,  like  albumen,  is  converted  into 
albuminose  in  the  small  intestine,  and  is  finally  disposed  of  in  the 
same  manner.  (See  p.  86.) 

Thus  all  the  tissues  of  the  young  mammalia  are  developed  for  a 
time  after  birth  from  the  caseine  (and  other  elements)  of  milk,  as 
those  of  birds  are  from  the  yolk  of  the  &gg.^  It  is  soon  coagulated 
by  the  action  of  the  gastric  fluid,  and  takes  the  form  of  curd,  and 
cannot  then  be  distinguished  from  coagulated  albumen.  The  "curd- 
ling" of  milk,  therefore,  in  an  infant's  stomach,  is  no  sign  of  disease, 
as  is  often  incorrectly  asserted. 

The  large  quantity  of  phosphate  of  lime  in  milk  adapts  this  fluid 
to  the  necessities  of  the  young  animals  while  the  bones  are  under- 
going rapid  development.  In  adults,  a  less  amount  in  the  albumen 
of  the  blood  is  sufficient  for  their  nutrition. 

Kiesteine^  a  substance  forming  a  thick  pellicle,  generally  exhaling 
the  odor  of  decomposing  cheese,  upon  the  urine  of  pregnant  women, 
has  been  regarded  as  being  allied  to  caseine,  and  as  probably  result- 
ing from  its  decomposition.  But  Lehmann  maintains  that  the  layer 
is  merely  a  formation  of  crystals  of  triple  phosphate  and  fungoid 
and  confervoid  growths,  which  takes  place  when  the  urine  becomes 
alkaline.  Still,  the  urine  of  pregnant  women  is  more  likely  to  pre- 
sent it,  though  it  is  not  peculiar  to  pregnancy.  It  occurs,  also,  in 
hysteria  and  chlorosis,  and  results  from  an  increased  tendency  to 
alkaline  fermentation. 

4.  Fihrine. 
Fibrine  is  found,  in  its  natural  fluid  state,  in  blood  (.19  to  .28  per 
cent.),  chyle,  and  lymph  (.052  per  cent.),  and  in  inflammatory  exu- 

'  Sulphate  of  soda  causes  the  membrane  to  burst  vrben  the  inclosed  fat  is  set  free. 
^  Lehmann  believes  that  the  vitelline  substance  forming  the  albuminous  body  of 
the  yolk  of  eggs  is  a  mixture  of  albumen  and  caseine. 


90  IMMEDIATE   PRINCIPLES   OF   THE   TISSUES. 

dations.  It  is,  by  some,  incorrectly  supposed  to  be  held  in  solution 
in  the  serum  associated  with  it.  It  is,  at  present,  regarded  as  con- 
taining one  atom  less  of  sulphur,  and  one  more  of  oxygen,  than 
seralbumen,  being  in  other  respects  isomeric  with  it;'  uniting,  like 
the  latter,  with  bases  as  an  acid,  and  with  acids  as  a  base.  It,  how- 
ever, contains  but  from  .7  to  2.5  per  cent,  of  the  phosphate  of  lime 
and  magnesia. 

Fibrine  has  been  said  to  exist,  in  its  solid  state,  in  muscular  fibre. 
It  does  not,  however,  exist  in  muscular  tissue  at  all. 

Fibrine  becomes  solid,  or  coagulates  spontaneously,  if  separated 
from  the  other  fluid  elements  of  the  blood ;  and  also  while  in  the 
blood,  in  all  ordinary  circumstances,  if  the  latter  be  removed  from 
the  vessels  and  from  all  contact  with  the  living  tissues.  After 
death,  it  also  normally  coagulates  Avithin  the  vessels. 

The  coagulum  of  fibrine  is  a  yellowish,  opaque,  fibrous  mass,  soft 
and  elastic,  and  containing  about  three-fourths  of  its  weight  of 
water.  Thus  coagulation  of  fibrine  \b  fibrillation^  and  is  a  vital  act. 
The  coagulum  of  albumen  has  no  fibres ;  it  is  merely  hyaline,  or 
minutely  granular,  albumen  not  being  endowed  with  vital  proper- 
ties. Mere  fibrillation  is  perhaps  the  lowest  form  of  organization, 
though  there  is  reason  to  believe  that  it  is  the  highest  of  which 
fibrine  is  capable. 

Any  alkaline  solvent  of  fibrine  prevents  its  coagulation — as  the 
sulphate  of  soda,  nitrate  and  carbonate  of  potassa,  and  the  chloride 
of  sodium.  Chloride  of  mercury  probably  has  the  same  property; 
so  also  have  acetic  and  phosphoric  acid.  All  these  substances 
diminish,  and  may  destroy,  the  vitality  of  fibrine. 

Origin  of  Fibrine. — The  fibrine  of  inflammatory  or  other  exuda- 
tions is,  of  course,  derived  wholly  from  the  blood.     That  in  the 

'  Dumas  states  that  fibrine  contains  less  carbon  and  more  nitrogen  than  albu- 
men. Carpenter  says  it  contains  (according  to  most  analyses)  more  oxygen  than 
albumen,  and  that  it  is  probably  albumen  oxidized  by  the  process  of  aeration. 

The  chemical  composition  till  recently  assigned  to  these  three  immediate  prin- 
ciples, regarding  them  as  proteine  compounds,  is  as  follows — assuming  Mulder's 
original  formula  for  proteine  (C.,(,H3|0,2N,),  or  Liebig's  (C^iHjgOj^Ng),  and  its  com- 
bining number  being  437.3  {Mulder),  or  526  3(J  (Lieliir/)  :— 

Ifiilder.         Liebig. 
Seralbumen  is  10  proteine  4- Pf'i !  combining  number,  4436.5(3     5327.16 

Fibrine  and  ovalbumen,  10  proteine -}- PS  ;  comb,  number,     4420.47     5311.07 
Caseine  and  crystalline,  10  proteine -|- S;  comb,  number,       4389.09     5279.09 

Mulder's  more  recent  formula  for  proteine  is  C3gH^5N^On,-|-2IIO. 


USES   OF   FIBRINE.  91 

blood  is  obtained  in  part  from  the  chyle  and  the  lymph ;  but  it  is 
also  probably  formed,  in  all  three  of  these  fluids,  from  their  albu- 
men. Were  we  content  with  a  mere  chemical  hypothesis,  we  might 
adopt  Lehmann's  as  the  most  plausible,  viz.,  that  "fibrine  is  pro- 
duced by  the  oxidation  of  albumen  in  the  aeration  of  the  blood, 
while  the  conversion  of  fibrine  into  the  tissues  is  also  the  result  of 
an  oxidation  of  fibrine.  But  fibrine  is  increased  in  inflammation, 
not  because  of  more  oxygen  in  the  blood,  but  because  there  is  less 
than  usual ;  there  being  harely  enough  to  form  the  fibrine  from  the 
albumen^  hut  not  enough  to  secure  the  metamorphosis  of  the  latter. 
Hence  the  highest  amount  of  fibrine  is  found  in  pneumonitis,  the 
disease  in  which  the  aeration  of  the  blood  is  most  impeded."  But 
oxidation  is  mere  chemical  action ;  and  it  is  entirely  abhorrent  to  our 
ideas  of  nutrition,  that  the  tissues  are  formed  from  any  immediate 
principle  by  an  exertion  of  mere  chemical  force.  Each  tissue  pos- 
sesses the  power  of  assimilation,  by  which  is  meant  the  power  of 
forming  its  own  substance  from  materials  in  the  blood,  which  are 
never,  as  there  found,  precisely  identical  in  composition  with  itself. 
So  it  is  probable  that  fibrine,  possessing  vitality,  develops  itself  from 
the  analogous  compound,  albumen,  and  fat,  and  a  few  saline  sub- 
stances.^ So,  also,  it  is  probable  that  fibrine  undergoes  its  own 
metamorphosis,  in  the  blood  or  out  of  it,  as  the  tissues  do ;  and 
when  it  is  formed  in  excess  in  the  blood,  this  may  be  owing  to 
either  an  excess  in  its  development,  or  a  diminished  metamorphosis, 
or  to  both  combined. 

Uses  of  Fibrine. — 1.  The  fibrine  in  the  blood  gives  to  it  the  power 
of  coagulating,  and  therefore,  within  certain  limits,  of  spontaneously 
arresting  hemorrhage.  In  case  of  ligation  of  a  vessel,  also,  it  is  the 
fibrine  which  prevents- the  escape  of  blood  when  the  ulcerative  pro- 
cess excited  by  the  ligature  cuts  off  the  vessel. 

2.  Fibrine  present  in  exudations  forms  the  nidus  in  which  adven- 
titious growths  are  developed,  or  in  which  new  tissues  are  formed, 
as  in  case  of  the  reparative  process.  Fibrine  appears  also  to  be  the 
forerunner  of  the  original  tissues,  or  the  matrix  in  which  they  are 
at  first  laid  down  during  intra-uterine  development;  but,  in  the  last 
two  cases,  the  fibrine,  after  fulfilling  its  temporary  office,  disappears. 
It  is  probable  that  the  fibrine  of  the  blood  docs  not  normall}^  con- 

'  For  fibrine  is  probably  a  compound,  and  not  a  simple  substance ;  as  is  also  the 
case  with  caseine.     See  "Remarks"  following. 


92 


IMMEDIATE   PRINCIPLES   OF   THE   TISSUES. 


duce  to  the  nutrition  of  the  permanent  tissues,'  and  that  it  becomes 
itself  permanent  only  in  persistent  false  membranes,  and  other  simi- 
lar pathological  epigeneses. 

Fibrine  is  probably  converted,  in  its  final  metamorphosis,  into 
urea,  uric  acid,  and  other  effete  substances,  like  albumen  and  the 
proper  tissues. 

Remarhs. — I,  It  is  not  probable  that  what  is  called  fibrine  is  a 
simple  substance.  It  always  contains  salts,  sulphur,  and  fat — even 
2,6  per  cent,  when  dry.  Besides,  Lehmann  remarks  that  it  is 
"wholly  at  variance  with  all  preconceived  ideas  to  attribute  life  to 
a  simple  organic  substance  ;"^  and  fibrine  manifests  a  property 
which  can  hardly  be  otherwise  than  vital,  viz.,  sjmitaneoiis  coagu- 
lahility. 

II.  Normally,  the  fibrine  coagulates  in  human  blood  to  such  an 
extent  as  to  give  the  blood  a  gelatinized  appearance  in  from  two  to 
four  minutes ;  in  inflammation,  this  appearance  is  delayed  ten  to 
fifteen  minutes,  or  longer.  In  case  of  filtered  frog's  blood,  or  of 
inflammatory  exudations  (the  red  corpuscles  being  in  both  of  these 
cases  separated  from  the  rest  of  the  blood,  so  that  no  obstruction  is 
offered  to  the  process  or  to  the  view),  molecular  granules  are  first 

seen  in  the  clear  fluid,  at  various 
^'     '  points,    from   which   very    fine 

straight  threads  are  next  seen  to 
radiate.  (Fig,  43,)  The  latter 
do  not,  however,  form  star-like 
masses  like  crystallization,  but 
they  finally  cross  each  other  in 
all  directions,  and  inclose  the 
colorless k corpuscles  (if  present), 
so  that  they  can  hardly  be  dis- 
tinguished in  the  network.  As 
coagulation  occurs  in  ordinary 
circumstances,  the  fibrine  at 
first  incloses  all  the  other  con- 
stituents of  the  blood,  and  the 
whole  mass  of  blood  appears  to  have  gelatinized.  But  the  contrac- 
tion of  the  fibrine  becoming  more  advanced,  the  serum  is  squeezed 


Fibres  in  coagulating  blood. 


'  See  chapter  on  the  "Histological  Relations  of  the  Blood.' 
2  Chemistry,  vol.  i,  p,  313. 


FIBRILLATION   OF   FIBRINE.  93 

from  its  meshes,  and  rises  on  tlic  surface,  while  the  corpuscles  (co- 
lored and  colorless)  remain  inclosed  in  the  coagulum.  Sometimes 
the  coagtdum  is  not  fully  contracted  under  forty  to  forty-eight 
hours.  When  the  fibrine  is  left  separate  from  all  other  elements, 
its  threads  or  fibrils  alone  occupy  the  field  of  vision,  and  afibrd  a 
striking  resemblance  to  the  membrane  lining  the  egg-shell.  (Fig.  48.) 

III.  Coagulation  is  fibrillation,  and  is  to  be  regarded  as  a  vital 
act,  since  it  is  organization,  thougb  perhaps  of  the  lowest  kind. 
But  fibrillation  is  the  last  and  the  highest  vital  act  of  the  fibrine. 
The  more  highly  vitalized,  therefore,  the  fibrine,  the  slower  and  the 
more  perfect  the  fibrillation.  Hence,  as  it  would  seem,  inflamma- 
tory blood  both  coagulates  most  slowly,  and  affords  the  most  com- 
plete fibrillation.  Indeed,  the  solidification  is  so  long  retarded  (ten 
to  twenty  minutes),  that  the  corpuscles — the  heaviest  portion  of  the 
blood — have  time  to  subside,  and  thus  leave  the  upper  portion  of  the 
clot  of  a  light  straw  color ;  and  which  has  given  to  the  coagulum, 
in  such  cases,  the  name  of  the  "buffy  coat."  This  is  characteristic 
of  inflammation,  however,  only  when  due  to  slow  coagulation.  It 
occurs,  also,  in  anaemia  and  chlorosis ;  the  coagulation  being  rapid 
in  these  conditions,  but  the  red  corpuscles  in  the  blood  being  so 
deficient  as  not  to  give  the  usual  bright  red  color  to  the  coagulum. 

IV.  The  fibrillation  of  fibrine  is  the  more  perfect  in  all  the  fol- 
lowing conditions: — 

1.  When  its  vitality  is  a-piparently  highest,  as  in  inflammation ; 
when  also  coagulation  is  most  slowly  performed. 

2.  When  it  is  most  nearly  isolated  from  the  other  elements  of 
the  blood,  especially  the  corpuscles,  as  in  inflammatory  exudations, 
which  consist  of  fibrine  and  serum  only  in  all  cases  except  when 
hemorrhage  also  has  occurred. 

3.  When  its  contact  is  most  perfect  ivith  th»  living  tissues,  as  in  case 
of  inflammatory  exudations  upon  serous  membranes,  when  the  ex- 
udation is,  of  course,  in  contact  with  the  tissues  on  hath  its  surfoces. 
In  case  of  inflammation  on  mucous  membranes,  or  the  skin,  the 
exudation  can  be  in  contact  only  on  one  surface,  except  in  the 
rectum,  vagina,  &c.  Hence  false  membranes,  so  called,  which  are 
originally  mere  fibrillated  fibrine,  are  more  common  on  serous  sur- 
faces, and  very  uncommon  on  mucous  membranes,  except  those 
just  mentioned. 

4.  When  it  is  at  perfect  rest  after  leaving  the  hloodvesseh.  Here, 
again,  a  serous  membrane  has  the  advantage.    In  pleurisy  and  peri- 


94  IMMEDIATE   PRIlSrCIPLES   OF   THE   TISSUES. 

tonitis  the  acute  pain  accruing  from  motion  secures  rest  of  the  dis- 
eased part.  Mucous  membranes,  lining  canals  for  the  passage  of 
foreign  substances,  are,  on  the  other  hand,  unfavorably  situated  in 
this  respect,  since  the  latter  may  disturb  the  contact  of  the  exuda- 
tion, or  even  remove  it  entirely.  The  latter,  however,  often  does 
not  occur,  and  therefore  false  membranes  (falsely  so  called')  may  be 
formed  on  the  pharynx,  in  the  rectum,  the  vagina  and  uterus,  and 
the  nasal  passages;  and  in  the  larynx,  trachea,  and  bronchial  tubes, 
especially  of  young  children. 

5.  When  a  temperature  of  98°  to  100°  Fahr.  is  uniformly  main- 
tained.    Here  an  internal  surface  or  part  has  the  advantage. 

Y.  On  the  other  hand,  all  the  circumstances  opposing  the  con- 
ditions just  mentioned  render  the  fibrillation  less  perfect.  These 
need  not  be  specified  at  length.  Any  agent  reducing  the  vitality  of 
the  fibrine,  diminishes  the  probability  of  the  formation  of  a  false 
membrane,  in  case  of  inflammation  on  a  serous  surface.  Alkalies, 
nitrate  of  potassa,  and  the  salts  of  mercury  (the  protochloride  espe- 
cially), appear  to  possess  this  property,  causing  the  exudation  to 
remain  longer  fluid,  and  thus  prolonging  the  opportunities  for  its 
reabsorption.  Hence,  if  these  agents  are  administered  too  freely, 
and  especially  when  the  fibrine  has  already  a  low  vitality  (as  in 
scrofulous  subjects),  the  exudation  may  be  converted  into  pus  in- 
stead of  a  false  membrane.  Empyema  may  thus  be  produced  from 
pleuritis,  in  a  delicate  patient. 

VI.  The  coagulation  of  the  blood  may  be  entirely  prevented  by 
any  cause  which  at  once  destroys  the  vitality  of  the  fibrine.  Such 
are — 

1.  Poisons  in  the  hlood,  as  in  case  of  malignant  typhus,  or  of 
glanders;  or  of  retention  in  the  blood  of  deleterious  secretions,  as 
carbonic  acid  gas  (in  asphyxia),  urea  (in  suppression  of  urine),  &c. 

2.  Violent  shocks  to  the  nervous  system,  as  from  mental  emotions,  or 
in  cases  of  death  from  lightning. 

3.  Too  high  a  temjjerature.  A  heat  of  180°  destroys  the  vitality 
of  the  fibrine,  and  coagulates  the  albumen  of  the  blood. 

VII.  The  following  agents  retard  the  coagulation  of  the  blood: — 

1.  Extreme  cold.  If  blood  is,  however,  frozen  at  once  on  being 
drawn,  it  coagulates  on  being  thawed. 

2.  Certain  narcotics  and  sedatives,  as  opium,  belladonna,  aconite, 

'  See  section  on  "False  Membranes." 


FIBRINE.— REMARKS.  96 

hyoscyamus,  digitalis,  and  strong  infusions  of  coffee  and  tea.  (Car- 
penter, Principles, d'c,  p.  195.)  Carbonic  acid  also  produces  the  same 
effect. 

3.  The  addition  to  the  blood  of  solutions  of  albumen,  caseine,  or 
sugar,  retards  its  coagulation.  On  the  contrary,  violent  agitation 
and  a  watery  condition  of  the  blood,  and  free  access  of  the  air, 
hasten  the  coagulation.'' 

VIII.  Fibrillation  being  the  only  distinguishing  histological  cha- 
racteristic of  fibrine,  it  is  clearly  unphilosophical  to  assume  that  an 
amorphous  mass  of  organic  matter  in  the  organism  is  fibrine,  merely 
because  it  is  solid,  as  in  exudations,  in  tubercle,  &c.  It  is  far  more 
probable  that  such  masses  are  merely  albumen,  and  not  fibrine.  It 
has  already  been  shown  that  it  is  not  possible  always  to  identify  and 
distinguish  albumen  and  fibrine  in  their  solid  form.  (p.  85.)  Fibrils 
alone  demonstrate  the  latter;  while  their  absence  merely  leaves  the 
inference  probable  that  the  substance  is  albumen, but  pror&s  nothino". 

IX.  Since  fibrine  is  indispensable  to  the  original  development  of 
the  tissues,  and  to  the  reparative  process,  as  it  affords  the  matrix  for 
the  new  growth,  all  the  agencies  mentioned  as  interfering  with  its 
perfect  fibrillation  are  obstacles  to  these  processes  also. 

X.  The  fluid  substance  from  which  the  tissues  are  directly  formed, 
or  repair  is  secured,  is  called  "plasma,"  "blastema,"  "hyaline  sub- 
stance," &c.  It  is,  in  fact,  the  liquor  sanguinis,  i.  e.  the  whole  blood, 
except  the  two  kinds  of  corpuscles.  It  was  formerly  called  "coagu- 
lating lymph"  by  Hunter  and  others. 

XI.  The  idea  generally  entertained,  that  fibrine  is  the  only  plastic 
element  of  the  blood,  must  now  be  received  with  suspicion.  It  is 
merely  the  only  spontaneously  plastic  or  organizable  element,  and 
the  first  organized — the  j^rimum  organizaturti — of  the  blood. 

XII.  Since  fibrine,  by  its  coagulation,  spontaneously  arrests  he- 
morrhage from  the  smaller  vessels,  the  hemorrhagic  tendency  in 
purpura,  scorbutus,  and  in  some  persons  constantly,  though  in 
health,  seems  due  to  a  low  vitality  of  the  fibrine,  or  an  insuflacient 
quantity. 

XIII.  Finally,  the  "polypi,"  so  called,  which  are  often  found  in 
the  heart  after  death,  are  mere  masses  of  coagulated  fibrine. 

'  It  should  be  added  here  that  Dr.  B.  W.  Richardson,  of  London,  has  recently 
received  the  Astley  Cooper  prize  for  his  investigations,  tending  to  demonstrate  that 
the  fluidity  of  the  blood  (i.  e.  of  ih.G  jihrine)  is  due  to  the  presence  of  free  ammonia. 


96  IMMEDIATE   PRINCIPLES   OF   THE   TISSUES. 


SECOND   DIVISION. 

Solid  or  Demi-solid  Immediate  Princi'ples. 

These  are  the  most  abundant  of  all  the  organic  substances,  and 
while  the  principal  substances  in  the  preceding  division  (albumen, 
albuminose,  and  fibrine)  are  found  in  the  blood,  all  these  (except 
globuline  and  crystalline)  exist  in  the  tissues.  These,  therefore,  are 
of  great  interest  to  the  histologist ;  though  most  of  them  have  been 
so  recently  announced,  that  our  knowledge  of  them  is  still  limited. 
They  are  seven  in  number. 

1.   Globuline. 

Globuline  is  found  only  in  the  red  corpuscles  of  the  blood.  The 
globuline,  together  with  the  hsematine  (the  haemato-globuline),  con- 
stitutes most  of  the  viscid  fluid  contents  of  the  blood-corpuscles. 
The  precise  proportion  of  each  has  not  yet  been  ascertained.  Eo- 
bin  and  Verdeil  remark  that  the  globuline  constitutes  the  principal 
part  of  the  mass  of  the  corpuscles. 

Globuline  is  not  soluble  in  serum,  but  is  so  in  water,  Avhich,  in 
dissolving  it,  destroys  the  corpuscles.  It  is  in  the  latter  united, 
molecule  to  molecule,  with  the  hjematine  and  with  some  fatty  sub- 
stances. 

Origin. — Since  globuline  is  found  only  within  cells  (blood-cor- 
puscles) bathed  by  an  albuminous  fluid,  we  can  hardly  avoid  the 
conclusion  that  it  is  developed  from  albumen  by  the  action  of  the 
cell-membranes.  Those  who  believe  in  the  oxidation  process  as 
forming  fibrine  from  albumen,  regard  globuline  as  an  intermediate 
substance  between  albumen  and  fibrine;  but  that  it  is  at  all  con- 
verted into  fibrine,  is  merely  a  chemical  hypothesis. 

Uses. — The  use  of  globuline  in  the  blood  is  unknown.  It  pro- 
bably exists  in  it  for  the  direct  advantage  of  the  blood  itself,  and 
not  as  a  pabulum  for  the  tissues. 

Globuline  probably  undergoes  its  own  peculiar  metamorphosis  in 
the  blood,  but  nothing  is  known  on  this  point. 

2,  Grystalline. 
This  substance  exists  only  in  the  crystalline  lens,  and  has  been 
regarded  by  some  chemists  as  identical  with  globuline.     Lehmann 
has,  however,  recently  asserted  that  they  are  distinct  substances, 


MUSCULINE.  97 

thougli  he  strangely  applies  tlie  name  crystalline  to  the  immediate 
principle  in  the  blood-corpuscles,  and  calls  that  in  the  lens  globu- 
liue.  Hence  he  terms  the  mixture  of  hasmatine  and  the  other  im- 
mediate principles  hasmato-crystalline.  We  have  applied  the  name 
hasmato-giobuline  to  the  same  (p.  96), 

In  the  human  crystalline  lens,  Berzelius  found  35.9  per  cent,  of 
dry  crystalline ;  which  also  contains  .241  per  cent,  of  phosphate  of 
lime.  It  probably  also  contains  phosphate  of  soda  and  ammonia. 
(Lehmann.)  Some  of  these  salts  exist  in  abnormal  amount  in  case 
of  hard  cataract. 

Origin. — Crystalline  is  probably  formed  from  the  albumen  in  the 
albuminous  fluid  (aqueous  and  vitreous  humors  of  the  eye),  sur- 
rounding the  crystalline  lens. 

Uses. — Crystalline  is  a  refractive  medium  in  the  crystalline  lens, 
as  albumen  is  in  the  other  humors  of  the  eye ;  and  Chenevix  first 
made  the  observation  that  this  principle  is  more  concentrated  in 
the  central  than  in  the  peripheral  portions  of  the  lens,  to  render  it 
achromatic. 

3.  Musculine. 

MusculinC' — also  called  syntonin'  by  Lehmann — exists  in  con- 
tractile tissue  alone,  i.  e.  in  both  the  striated  and  the  non-striated 
muscular  tissue.  Its  precise  amount  in  human  muscle  is  not  yet 
determined.  Most,  if  not  all,  that  has  been  called  fibrine  in  muscu- 
lar tissue  is  actually  musculine.  In  the  ox  it  constitutes  60  to  85 
per  cent,  of  the  solid  portion  of  the  muscles,  or  15.4  to  17.7  per  cent, 
of  their  substance.  In  the  calf  it  does  not  amount  to  more  than  50 
per  cent,  of  the  solid  matter. 

Musculine  is  soluble  in  water  containing  one-tenth  its  weight  of 
hydrochloric  acid ;  blood-fibrine  merely  swells  in  this,  but  does  not 
dissolve.  Musculine  contains  1.4  per  cent,  of  phosphate  of  lime, 
but  no  iron,  while  the  latter  is  found  in  blood-fibrine. 

Musculine  is  always  associated,  in  muscle,  with  albumen,  creatine, 
and  creatinine,  inosic  and  lactic  acids,  chloride  of  sodium  and  potas- 
sium, &c.;^  but  these  all  exist  in  the  muscular  Juice,  which  will  be 
discussed  in  the  chapter  on  "Contractile  (Muscular)  Tissue." 

'  From  <rwT6ivEiv,  to  strain. 

2  Scherer  has  recently  found  inosite,  or  muscle  sugar,  also  in  the  muscular  juice 
of  the  heart  of  the  ox. 

7 


98  IMMEDIATE   PRINCIPLES   OF   THE   TISSUES. 

Origin. — There  is  no  reason  to  doubt  that  musculine  is  formed 
from  the  albumen  (and  albuminose)  in  the  blood.  The  necessity 
for  admitting  that  muscular  tissue  is  formed  from  the  blood-fibrine 
ceases  to  exist  when  it  is  demonstrated  that  fibrine  does  not  exist 
in  it.  And  no  physiological  objection  occurs  to  the  idea  that  albu- 
men may  be  directly  converted  into  musculine  as  readily  as  into 
fibrine.     How  the  conversion  occurs,  in  either  case,  is  unknown. 

Uses. — Musculine  is  the  main  constituent  and  essential  substratum 
of  the  contractile  (muscular)  tissue.  It,  especially,  is  endowed  with 
the  vital  property  of  contractility^  though  other  immediate  principles 
are  doubtless  united  with  it,  molecule  to  molecule,  and  without  which 
it  could  not  manifest  the  property  just  mentioned.  It  forms  the 
fibrils  of  striated  muscular  tissue,  and  is  always  bathed  in  a  fluid  of 
an  acid  reaction,  called  the  muscular  juice.  The  latter,  however, 
results,  probably,  in  great  part  at  least,  from  the  metamorphosis  of 
the  musculine ;  and  since  it  contains  creatine,  creatinine,  lactic  acid, 
&c.,  these  substances  are  doubtless  the  immediate  results  of  its  trans- 
formation. 

Remarks. — Fresh  muscular  fibre,  even  of  inferior  quality,  nou- 
rishes an  animal  indefinitely ;  while  blood-fibrine,  with  the  addition 
of  soup,  nourished  only  about  a  month,  when  the  animal  refused 
for  three  days  to  take  it.  {3fagendie.)  Of  the  former,  150  to  300 
parts  are  better  than  1,000  of  blood-fibrine,  with  some  albumen 
added.  {Robin  and  Verdeil) 

Boiling  converts  musculine  into  a  substance  allied  to  gelatine; 
roasting  does  not.  Hence  boiled  meat  is  far  less  nutritious  than 
the  same  when  broiled  or  roasted. 

Musculine  is  more  abundant  in  the  muscles  of  the  ox  and  of  the 
common  fowl,  than  in  those  of  the  sheep.  Hence  beefsteak  is  one 
of  the  most  nutritious  substances  for  the  muscular  system  of  man. 
It  is  also  much  more  so  than  veal,  since  there  is  less  musculine  in 
the  muscles  of  young  animals. 

4.  Osteine. 

This  is  the  name  given  by  Robin  and  Verdeil  to  the  still  unde- 
scribed  substance  from  which  glutin  (or  gelatine)  is  obtained  by  the 
action  of  boiling  water;  for  glutin  does  not  naturally  exist  in  the 
human  body. 

Osteine  exists  in  bone  and  in  white  fibrous  tissue,  wherever  found 
(in  tendons, ligaments,  the  cornea);  and  in  permanent  cartilages  when 


CARTILAGEINE.  99 

they  become  ossified  in  disease.   In  fishes  it  exists  in  the  swimming- 
bladder  and  in  the  scales. 

The  chemical  composition  of  osteine  is  unknown.  It  probably 
differs  from  glutin  by  a  few  atoms  of  water,  at  most.  [Lehmann.) 
But  the  composition  of  the  latter  is  not  yet  settled;  Liebig's  formula 
being  C,,Il,,-Nfi,,,  while  Mulder's  is  G,,IL,,-Np,. 

Osteine  constitutes  a  large  part  of  the  mass  of  the  human  organ- 
ism. Haller  remarked  that  "one-half  of  the  human  body  is  glutin." 
In  fact,  one-half  of  the  solid  part  of  the  body  is  convertible  into  glu- 
tin hj  hoiling  in  ivater. 

In  the  bones,  osteine  is  chemically  combined  with  the  phosphate 
of  lime,  and  constitutes  from  17.3  to  27.99  per  cent,  of  the  bone-sub- 
stance; water  constituting  from  47.22  to  22.87  per  cent.  {Magendie.) 

Origin. — Osteine  is  formed  in  the  tissues  in  which  it  occurs,  by 
assimilation  of  the  albuminous  elements  of  the  blood,  like  globuline 
and  musculine. 

Uses. — Osteine  is  the  essential  organic  element  in  bone  and  white 
fibrous  tissue.  It,  however,  manifests  but  very  low  vital  endow- 
ments, merely  in  the  way  of  nutrition  and  reproduction,  in  these 
tissues.  Hence  the  latter  belong  to  the  lowest  class,  and  are  useful 
only  on  account  of  their  physical  properties ;  the  bones  giving  sup- 
port to  the  body  and  strong  points  for  the  attachment  of  muscles, 
and  the  white  fibrous  tissue  subserving  various  uses  on  account  of 
its  strength  and  flexibility,  and  its  almost  total  inextensibility.  The 
cornea  is  useful  from  its  strength  and  transparency. 

The  transformations  of  osteine  are  not  understood. 

Remarks. — Osteine  is  nutritious  and  assimilable ;  glutin  is  not, 
but,  if  it  enters  the  blood,  appears  in  the  urine.  Hence  Magendie 
found  that  animals  may  be  sustained  indefinitely  by  giving  them 
finely  ground  bones,  while  they  soon  languish  if  they  are  fed  with 
soup  obtained  by  boiling  the  bones ;  since  in  the  latter  case  the 
osteine  is  converted  into  glutin. 

5.   Cartilageine. 

The  substance  which  by  the  prolonged  action  of  boiling  water  is 
converted  into  chondrine,  is  named  cartilageine.  {Robin  and  Verdeil.) 
It  is  found  only  in  cartilages  and  in  fibro-cartilages.  It  exists  abun- 
dantly in  the  intercellular  substance  of  cartilage;  whether  in  its 
cells,  also,  is  not  certainly  ascertained. 

Cartilageine  exists  in  bone-cartilage  as  well  as  in  the  permanent 


100  IMMEDIATE   PRINCIPLES   OF   THE   TISSUES. 

variety ;  but  as  soon  as  ossification  occurs  in  the  former,  osteine  is 
found,  and  cartilageine  disappears  as  the  process  goes  on. 

The  chemical  composition  of  cartilageine  probably  differs  very 
little  from  that  of  chondrine ;  but  even  the  latter  is  not  yet  decided. 
Mulder's  formula  is  CgjHjgTST^Oi^;  Liebig's,  C^gH^oNgOgQ.  The  origin 
of  cartilageine  is  not  definitely  decided,  but  it  is  probably  formed 
directly  from  the  albuminous  elements  of  the  blood.  Nothing  is 
known  of  its  metamorphoses. 

Uses. — Cartilageine  is  the  essential  organic  element  of  cartilage, 
and  in  which  the  vitality  of  this  tissue  especially  resides.  It,  how- 
ever, manifests  even  a  lower  vitality  than  osteine  in  the  way  of 
nutrition  and  reproduction ;  and  hence  this  tissue  is  useful  merely 
on  account  of  its  physical  properties,  and  especially  of  its  elasticity. 

Remarks. — The  idea  is  untenable  that  glutin  is  formed  from  chon- 
drine— or,  rather,  that  osteine  is  formed  from  cartilageine — because 
bone  is  formed  from  cartilage;  for  as  bone  merely  replaces  cartilage, 
so  the  osteine  replaces  the  cartilageine.  Attempts,  therefore,  to 
explain  how  either  of  these  immediate  principles  is  formed  from  the 
other,  are  both  uncalled  for  and  unproductive. 

Miiller  has  shown  that  in  cases  of  softening  of  the  bones,  where 
there  is  a  diminished  amount  of  the  phosphate  of  lime,  neither 
glutin  nor  chondrine  is  obtained  by  boiling  them. 

6.  Elasticine, 

This  is  the  peculiar  organic  element  in  the  yellow  fibrous  or 
elastic  tissue.  {Bobin  and  Verdeil.) 

Its  chemical  composition  is  not  determined,  nor  is  its  amount  in 
the  tissue  above  mentioned. 

Uses. — It  possesses  but  a  very  low  degree  of  vitality ;  hence  the 
elastic  tissue  subserves  merely  physical  requirements.  Its  great 
extensibility  and  elasticity  are  its  characteristic  properties. 

7.  Keratin e. 

Keratine  is  the  organic  immediate  principle  peculiar  to  epidermis, 
nails,  hair,  wool,  and  horn. 

A  small  amount  of  the  fatty  principles  is  chemically  combined 
with  this  principle. 

Uses. — It  is  doubtful  if  keratine  possesses  vitality.  At  all  events, 
it  merely  gives  hardness  and  other  physical  properties  to  the  tissues 


COLORING   ORGAXIC   SUBSTANCES.  101 

just  mentioned,  and  which  are  constantly  falling  off  from  the  body 
as  excrementitious. 


THIRD   DIVISION. 
Coloring  or  Colored  Organic  Substances. 
Under  this  head  are  included — 

1.  Hsematine — the  coloring  matter  in  the  blood-corpuscles. 

2.  Biliverdin — in  the  bile. 

3.  Melanine — in  melanotic  deposit,  &c. 

4.  Urrosacine — in  urine. 

1.  The  urine-pigment  is  of  no  importance  in  histology,  and  will 
be  merely  mentioned  here. 

2.  The  hile-pigment^  also,  will  be  but  briefly  alluded  to.  The 
biliverdin  is  the  green,  the  cholepyrrhin  {Berzelius)  or  biliphaein 
(Simon)  is  the  brown,  and  the  bilifulvin  is  the  yellow,  coloring-matter 
of  the  bile.  The  last  is  entirely  converted  into  hgematoidine  (see  p. 
102),  and  is  formed  in  stagnant  bile  as  hgematoidine  is  in  stagnant 
blood. 

The  greenish  color  of  the  feces  (as  in  diarrhoea)  is  generally  due 
to  an  admixture  of  decom.posed  blood,  and  rarely  to  the  presence  of 
biliverdin.  Bile-pigment  is,  however,  never  entirely  absent  from 
the  feces,  except  in  some  rare  cases  of  icterus.  Nothing  is  known 
of  the  origin  of  the  bile-pigment.  It  is  probably  not  formed  in  the 
liver.  (Lehmann.) 

In  diseases,  bile-pigment  may  be  found  in  the  urine,  in  the  fluid 
of  the  areolar  tissue,  and  even  in  the  sweat  and  the  saliva.  It  is 
also  deposited  in  all  the  fluids  of  the  eye,  and  in  the  sclerotic  coat. 
Sometimes,  indeed,  the  saturation  of  the  organism  is  so  extreme  as 
to  color  the  cartilages,  ligaments,  bones,  and  even  the  nerves. 

3.  Rcematine.  (C^^B.^^^fi^'Ee.) 
Haematine  occurs  only  in  the  red  corpuscles  of  the  blood  of  the 
higher  animals,  and  gives  the  latter  its  bright  red  color.  It  consti- 
tutes 1.675  per  cent,  of  the  moist  corpuscles,  and  about  .73  per  cent. 
of  the  whole  blood;  but  this  substance  obtained  by  the  chemist  is 
not  the  coloring-matter  as  it  naturally  exists  in  the  corpuscles,  but 
is  a  product  of  its  metamorphosis.  It  is  naturally  dissolved  in  the 
globuline  in  the  corpuscles,  but  can  be  obtained  only  in  its  coagu- 


102  IMMEDIATE   PRINCIPLES   OF   THE   TISSUES. 

lated — and,  of  course,  modified — condition.    Its  combining  number 
is  5175.  {Mulder) 

Iron  is  always  found  in  combination  witli  btematine ;  but  whether 
in  the  state  of  an  oxide  or  not,  is  not  yet  decided.  It  is,  however, 
not  probable  that  the  single  equivalent  of  this  metal  is  chemically 
combined  with  the  group  of  atoms  representing  pure  hrematine, 
C44II22N3O6  [Mulder)^  and  it  is  demonstrated  that  iron  may  be  ab- 
stracted from  the  haimatine  without  affecting  its  bright  red  color. 
It  constitutes  Q.Q-^  per  cent,  of  the  hsematine  {Mulder)^  and  .88  per 
cent,  of  the  dried  red  corpuscles  {Berzelius) ;  and  about  .05  per  cent, 
of  the  blood.  Iron  also  exists  in  chyle  and  in  the  colorless  parts  of 
the  blood. 

Hcematoidine  (otherwise  called  xanthose)  was  first  observed  by 
Virchow,  and  is  found  in  amorphous  or  jagged  masses,  in  granules, 
in  globules,  or  in  perfectly  formed  crystals.  It  always  occurs  in 
corpora  lutea,  and  often  in  old  extravasations  in  the  brain,  in  obli- 
terated veins,  in  subcutaneous  suggillations,  and  in  purulent  abscess 
of  the  extremities.  ( Virchow.)  It  may  be  found  in  extravasations 
at  the  end  of  seventeen  to  twenty  days.  Its  crystals  are  of  a  yel- 
lowish red,  a  red,  or  a  ruby  color.  It  is  doubtless  formed  from 
hsematine,  resulting  from  the  metamorphosis  of  the  latter.  It  has 
also  been  stated  that  it  may  be  formed  from  bilifulvin  (p.  101). 

Origin. — Nothing  is  known  of  the  origin  of  hajmatine.  It  exists 
in  the  thoracic  duct,  but  may  have  entered  it  from  the  blood  in  the 
mesenteric  glands,  or  have  come  from  the  blood-corpuscles  which 
have  passed  into  the  chyle  with  the  splenic  lymph. 

Doubtless,  however,  the  h^matine  is  first  formed  within  the  mem- 
brane of  the  colored  blood-corpuscles;  and  the  most  probable  hy- 
pothesis is  that  of  Lehmann,  according  to  which  hiematine  is  formed 
from  fat,^  by  its  oxidation. 

Uses. — The  constant  occurrence  of  ha3matine  in  the  blood-cor- 
puscles of  all  the  higher  animals  leaves  no  doubt  of  its  importance, 
but  its  precise  use  is  not  yet  determined.  It,  however,  gives  to 
blood  the  color  by  which  we  may  at  once  distinguish  it  from  all 
the  other  animal  fluids.  It  has  also  been  supposed  to  be  especially 
connected  with  the  respiratory  process.  The  experiments  of  Briicli 
and  Harless  show  that  the  inspired  oxygen  acts  on  the  corpuscles 
and  their  contents,  and,  of  course,  upon  the  htcmatinc;  but  what  the 

'  I'liysiological  Chemistry,  vol.  i.  p.  273. 


COLORING   ORGANIC   SUBSTANCES. 


103 


precise  action  is,  can  still  be  only  conjectured.  And  yet  the  idea 
that  the  hoematine  or  the  corpuscles  are  alone  or  mainly  acted  upon 
by  the  inspired  oxygen  seems  to  be  weakened  by  the  observations 
of  Hannover,  which  show  that  chlorotic  persons,  whose  blood  is 
poor  in  red  corpuscles,  exhale  as  much  carbonic  acid  as  healthy 
persons. 

The  probability  that  hsematine  is  finally  transformed  into  hasma- 
toidine  has  already  been  shown.  From  it,  also,  melanine  is  proba- 
bly derived. 

In  connection  with  heeraatine  should  be  mentioned  the  red  crys- 
tals first  observed  and  obtained  from  the  red  blood-corpuscles  by 
Funke,  and  which  Lehmann  terms  the  albuminous  crystalline  sub- 
stance of  the  blood.     Fig.  44  shows  the  form  of  these  crystals  in 


Fig.  44. 


Fig.  45. 


^%^>j;'^^''^ 


°L^;^^'-:xn:'p 


rfM2p-^__,sf 


^^/ 


Crystals  of  human  venous  Wood. 


Crystals  from  blood  of  the  guinea-pig. 


human  blood,  and  Fig.  45  those  obtained  from  the  corpuscles  of  the 
guinea-pig.     They  are  not  formed  till  after  the  corpuscles  burst. 

The  relation  of  these  crystals  to  hsematine  is,  doubtless,  important; 
they  being  the  substance  from  whose  metamorphosis  hsematine  is 
probably  produced. 

4.  Melanine. 

This  is  the  dark  pigment  found  on  the  choroid  coat  of  the  eye, 

and  in  pigment-cells  generally.     The  melanotic  deposit,  so  called, 

also  probably  consists  of  it.    Its  formula  is  not  j^et  ascertained.    It 

is  certain  that  the  pigment  often  deposited  in  the  lungs  as  a  morbid 


10-i  IMMEDIATE   PRINCIPLES   OF  THE   TISSUES. 

product  varies  mucTi  in  composition,  and  abounds  in  carbon — 66  to 
72  per  cent.  {Schmidt.)  Melaniue  occurs  in  the  black  serum  which 
has  sometimes  been  observed. 

Melanine  is,  doubtless,  derived  from  haematine.  In  the  choroid 
coat  it  contains  .254  per  cent,  of  iron.  {Lehmann.)  It  occurs  within 
all  pigment  cells,  in  the  form  of  granules;  and  in  other  cases,  espe- 
cially in  melanotic  tumors,  it  is  also  found  scattered  among  cells  or 
tissues.  In  the  choroid  coat  of  the  eye  this  pigment  is,  doubtless, 
subservient  to  vision.  For  other  particulars,  see  the  section  on 
"Pigment-cells." 


Having  thus  completed  the  description  of  the  immediate  princi- 
ples of  which  the  solids  and  fluids  of  the  human  body  are  composed, 
we  next  enter  upon  Histology  proper. 


PART    II. 

HISTOLOGY 


DEFINITIONS,  SUBDIVISIONS,  ETC. 

Histology^  is  the  scientific  classification  and  description  of  the 
structuraP  or  organized  elements  of  the  solids  and  fluids  of  living 
organisms.  Since  these  elements  can  be  demonstrated  only  by 
the  aid  of  the  microscope,  Histology  is  one  of  the  subdivisions  of 
minute  or  microscopic  anatomy.^  It  also  includes  Histogeny,  or  the 
development  of  the  elements  just  mentioned. 

Animal  Histology,  Vegetable  Histology,  and  Human  Histology, 
are  terms  requiring  no  special  explanation.  Comparative  Histology 
is  the  study  of  the  structural  elements  of  the  lower  animals.  Pa- 
thological Histology  is  the  study  of  the  minute  structure  of  the 
organism  as  modified  by  disease. 

If  we  investigate  the  structural  elements  in  their  general  rela- 
tions only,  and  without  regard  to  their  distribution  in  particular 
parts  or  organs,  this  is  General  Histology ;  if  in  regard  to  the  latter 
particulars,  it  is  Special  Sistology. 

Thus  explained,  the  present  is  a  treatise  on  Human  Histology, 
both  general  and  special,  and,  at  the  same  time,  both  physiological 
and  pathological.     Thus  the  subjects  it  includes  will  be  found  to 

■  From  'is-Tof,  a  web  or  network,  and  \oyof,  description. 

^  "Morphological  elements"  is  a  plirase  sometimes  employed  in  the  same  sense. 

'  Histology  may,  indeed,  be  regarded  as  general  microscopic  anatomij.  If  we 
investigate  microscopically  merely  the  structure  of  a  part  or  organ,  without  any 
ulterior  object,  this  is  special  microscopic  anatomy.  And  if  we  thus  investigate 
the  structure  of  the  various  organs  with  the  view  to  establish  their  functions,  or 
scientifically  to  associate  the  latter  with  the  structure,  we  are  contributing  to  the 
department  now  known  as  pIii/siolo(jical  anatomy. 


106  DEFINITIONS,    SUBDIVISIONS,    ETC. 

underlie  tlie  whole  domain  of  anatomy  (as  usually  taught),  and  of 
physiology  and  pathology.  Coiwparaiive  Histology  will  also  be  in- 
troduced, especially  so  far  as  it  gives  interest,  by  its  analogies  or  its 
contrasts,  to  the  study  of  the  tissues  in  the  human  organism. 

The  structural  elements  of  the  human  organism  may  be  arranged 
in  two  classes : — 

I.  The  simple  histological  elements. 
11.  The  tissues,  properly  so  called. 

The  second  part  of  this  work  will  consist  of  three  divisions,  con- 
taining— 

I.  A  description  of  the  simple  histological  elements,  their  distri- 
bution, development,  &c. 
II.  Of  the  fluids  in  the  human  body  which  contain  histological 

elements. 
III.  Of  the  tissues,  properly  so  called. 


riliST  DIYISION. 

THE  SIMPLE  HISTOLOGICAL  ELEMENTS. 

The  various  structural  forms  presented  to  the  liistologist  in  the 
solids  and  fluids  of  the  human  body  may  be  included  under  the 
five  following  heads: — 

I.  Homogeneous  substance. 
II.  Simple  membrane. 

III.  Simple  fibre. 

IV.  Cells. 

Y.  The  tissues  proper. 

All  these  are  developed  from  the  elements  in  the  blood  which 
are  required  for  their  nutrition,  and  in  a  manner  to  be  described  in 
connection  with  each. 

The  four  first  mentioned  of  the  preceding  forms  constitute  the 
simple  histological  elements,  or  elements  of  which  the  proper  tissues 
are  directly  or  indirectly  formed,  and  will  be  first  of  all  considered. 


CHAPTER    I, 


HOMOGENEOUS   SUBSTANCE. 


By  this  is  meant  a  more  or  less  solid,  structureless  substance, 
which  enters  into  the  composition  of  several  of  the  tissues.  In  a 
thin  section  it  resembles  a  mere  layer  of  solidified  albumen. 

It  often  fills  up  the  spaces  between  the  fibres  or  the  cells  of  com- 
pound tissues ;  e,  g.  cartilage  and  fibro-cartilage.  Consequently  it 
may  constitute  a  large  part  of  the  mass  of  certain  tissues.  Of  pa- 
thological epigeneses,  it  exists  in  cancer,  sometimes  forming  a  large 


108 


SIMPLE   HISTOLOGICAL   ELEMENTS. 


Fig.  46. 


part  of  its  mass,  and  giving  it  its  hardness.  (Gluge,  p.  37.)     It  is, 
also,  one  of  the  elements  of  tubei'cle. 

From  its  structureless  appearance,  and  its  transparency  when 
seen  in  section,  it  has  also  been  termed  hyaline  substance.'  In  rela- 
tion to  the  other  elements  of  compound  tissues,  it  is  sometimes 
termed  a  homogeneous  matrix^  in  which  the  other  elements  (cells, 
fibres,  &c.)  are  said  to  be  imbedded. 

In  some  cases,  however,  minute  granules  appear  in  this  histo- 
logical element.     Its  two  forms,  therefore,  are  the  hyaline  and  the 

granular  homogeneous  sub- 
stance. When  in  its  lowest 
form,  as  in  some  cancers,  it 
seems  to  be  mere  coagulated 
albumen.  In  the  tissues,  how- 
ever, the  homogeneous  sub- 
stance appears  always  to  have 
attained  to  a  higher  stage  than 
mere  albumen,  though  it  is 
very  probably  always  deve- 
loped from  that  element  in  the 
blood.  For  example,  the  ho- 
mogeneous matrix  of  cartilage 
contains  cartilageiue,  and  not 
albumen,  while  that  of  bone 
and  dentine  contains  osteine  only.  On  the  other  hand,  some  can- 
cerous deposits  afford  merely  albuminous  products  on  being  boiled, 
while  others  afford  gelatine,  and  thus  show  that  osteine  existed  in 
them.  In  the  latter  case,  however,  there  are  fibres  of  white  fibrous 
tissue,  as  well  as  homogeneous  substance,  in  the  cancerous  deposit, 
and  this  tissue  may  have  afforded  all  the  gelatine  to  the  boiling 
water  (p.  98). 

Origin. — If  the  lowest  form  of  homogeneous  substance,  whether 
granular  or  not  (as  in  cancer),  appears  to  be  simply  coagulated  albu- 
men, it  is  really  something  more — something  possessed  of  vital 
endowments — in  all  the  tissues ;  though  probably  formed  from  the 
albumen  of  the  blood,  in  each  of  them,  by  assimilation. 

Functions. — In  its  lowest  form,  it,  therefore,  hardly  does  more 
than  serve  as  a  cement  to  connect  other  histological  elements  to- 


Homogeneous  substance  and  cells  of  cartilage  a. 
Group  of  four  cells,  separating  from  each  otlier.  h. 
Pair  of  coUs  in  apposition,  c,  c.  Nuclei  of  cartilage 
cells,  d.  Cavity  containing  three  cells.  The  granu- 
lar homogeneous  suhs:auce  is  seen  between  the  cells. 


From  '6a.Xo;,  glass,  it  resembling  a  lamina  of  this  substance. 


SIMPLE   MEMBRANE.  109 

gether ;  while  in  its  higher  developments,  as  in  bone,  &;c.,  it  mani- 
fests the  vital  functions  characteristic  of  the  tissue  of  which  it  forms 
a  part.  The  latter  arc,  however,  always  of  a  low  grade,  as  mere 
nutrition  and  reparation,  since  all  the  tissues  in  which  it  abounds 
are  useful  rather  from  their  mechanical  than  their  vital  properties. 
Dislrihution. — It  abounds  in  bone  and  cartilage,  and  in  the  morbid 
developments  already  mentioned. 

In  j^c^ohological  states,  homogeneous  substance  may  undergo  a  fatty 
degeneration  ( Wedl),  oil-glob  ales  being  deposited  in  it.  Pigmentary 
substances  are  also  often  found  in  it. 


CHAPTER   II, 


SIMPLE   MEMBEANE. 


Simple  membrane  usually  appears  as  a  very  thin,  transparent, 
and  perfectly  structureless  layer  of  coagulated  albumen  or  plasma, 
often  not  more  than  ^^^^-^  of  sua.  inch  in  thickness.  It  is  nourished 
by  vessels  lying  near  or  under  it,  but  is  never  penetrated  by  any 
vessel,  nerve,  or,  indeed,  by  any  other  tissue  whatever.  It  is  entirely 
imperforate  at  every  part,  the  highest  powers  of  the  microscope 
never  revealing  any  pores,  or  openings  of  any  kind.  Forming, 
therefore,  a  complete  barrier  between  the  structures  on  its  opposite 
sides,  it  has,  in  some  parts,  been  termed  a  limitary  membrane. 

The  posterior  layer  of  the  capsule  of  the  crystalline  lens  aftbrds 

an  excellent  illustration  of  this  kind  of  tissue.  -p,.     ,„ 

Fig.  47. 

Being  structureless  and  transparent,  it  can,  how- 
ever, only  be  seen  when  accidental  folds  or  other 
irregularities  are  formed.  (Queckett,  p.  116.) 

In  some  case,  however,  granules  also  appear  in 
simple  membrane;  and  in  a  third  form  of  it  dis- 
tinct spots  appear,  which  have  been  regarded  as 
nuclei ;  and  it  may  be  broken  up  into  separate 
portions,  each  containing  one  of  these.    (Fig.  47.) 


BasemiTit  nipinbrane  of 
nfrs 

plasma,  the  second  is  probably  the  same  sub-    tiw. 


If  the   simplest  form   is   solidified  albumen  or   . 

^  infra-gliuidular  lynipha- 


110  SIMPLE   HISTOLOGICAL    ELEMENTS. 

stance,  containing  granules  in  it;  and  the  third  form  is  an  instance 
of  the  development  of  scales  from  germinal  points,  or  nuclei,  as  cells 
are  normally  developed  (Chap.  IV.),  and  which  scales  coalesce  at 
their  borders  to  form  the  continuous  layer.  In  all  these  cases,  how- 
ever, it  is  organized,  and  manifests  vital  properties. 

Simple  membrane  is  found  only  in  two  conditions,  except  when 
an  element  of  the  compound  tissues,  viz.,  in  the  form  of  a  mem- 
branous expansion,  to  constitute — 

1.  Basement  membrane,  which  will  be  described  at  the  end  of 
this  chapter. 

2.  As  constituting  the  walls  of  cells,  whether  secreting,  absorbing, 
or  primordial,  &c.  &c. 

Properties  of  Simple  Membrane. — Though  the  simplest  of  the  histo- 
logical elements,  it  manifests  important  vital  properties.  Since  it 
forms  the  walls  of  cells  (secreting  and  otherwise),  simple  membrane 
is  the  direct  agent  of  secretion  in  all  cases.  It  is  also,  in  many  in- 
stances, of  absorption.    These  are,  therefore,  its  two  vital  properties. 

The  physical  property  of  endosmosis  also  inheres  in  it  in  a  re- 
markable degree.^ 

Distribution  of  Simple  Mem^brane. — The  basement  membrane  of 
the  skin,  and  of  serous  and  mucous  membranes,  is  formed  of  this 
element.  It  therefore  enters  the  lobes  and  follicles  of  all  glands. 
It  forms  the  capsule  of  the  crystalline  lens,  and  the  posterior  layer 
of  the  cornea.  It  lines  the  bloodvessels  and  the  lymphatic  vessels, 
in  the  form  of  epithelium,  if  not  of  a  basement  membrane  also. 

It  forms  the  walls  of  all  cells,  whether  blood-corpuscles,  secreting 
cells,  fat-cells,  &c.  &c.^ 

As  an  element  of  compound  tissues,  it  also  constitutes  the  myo- 
lemma  of  the  muscular  fibres,  and  the  neurilemma  of  the  nerve- 
fibres  or  tubes. 

Simple  membrane  will,  therefore,  constantly  recur  in  the  descrip- 

'  By  endosmosis  is  meant  the  property  inherent  in  animal  membranes,  of  trans- 
mitting tluids  tlirough  them.  If  two  fluids  of  different  specific  gravity  are  placed 
on  opposite  sides  of  them,  they  are  transmitted  in  opposite  directions,  and  thus 
mixed — one  current  being  termed  endosmosis,  and  the  other  exosmosis. 

^  Simple  membrane  also  forms  the  walls  of  the  cells  from  which  the  tissues  of 
vegetables  are  developed  ;  it  being  identical  in  them,  it  is  said,  with  cellulose, 
C24H2,02„  or  C^-{-Aqaa,y.  It  is  an  interesting  fact,  if  verified  by  futu.e  investiga- 
tions, that  the  vegetable  cell  is  lined  by  a  "primary  utricle"  or  cell,  identical  in 
composition  with  proteine — i,  e.  it  is  an  albuminous  compound,  as  is  the  animal 
cell-wall. 


SIMPLE   MEilBRANE.  HI 

tion  of  cells  and  of  tlie  various  tissues;  and,  in  connection  with 
these,  its  important  vital  relations  will  be  particularly  indicated. 

Basement  Membrane. 

A  basement  membrane  is  a  mere  expansion  of  simple  membrane 
entering  into  the  structure  of  the  skin,  and  all  mucous  and  serous 
membranes,  and  lying  directly  upon  the  corium  of  these  structures 
respectively.  It  is  itself  covered,  in  turn,  by  the  epithelium  of  the 
serous  and  mucous  membranes,  and  the  epidermis  of  the  skin.  Its 
thickness  is  often  not  more  than  =j^  Jo(j  ^^  ^^  inch. 

Kcilliker  does  not  mention  the  basement  membrane  at  all  as  an 
element  of  the  three  tissues  just  mentioned.  There  is,  however,  no 
doubt  of  its  existence  in  many  parts  of  them.  It  has  been  shown 
that  simple  membrane  presents  three  forms ;  and  Queckett  asserts 
the  probability  that  in  one  or  another  of  these,  basement  membrane 
exists  in  every  part  of  the  three  membranes  just  mentioned. 

Uses. — The  basement  membrane  is  a  complete  barrier  between 
the  vessels  and  nerves  of  the  corium  on  the  one  hand,  and  the 
epithelium  on  the  other,  being  never  perforated  by  any  structures 
whatever.  It  thus  rises  over  and  covers  the  villi  of  the  small  in- 
testine, and  the  papillse  of  the  skin.  It  also  dips  down  into  and 
lines  all  the  sebaceous  follicles  and  sweat  ducts  of  the  latter,  and  the 
mucous  follicles  of  the  former.  Thus  it  forms  everywhere  the  basis 
of  the  epidermis  and  of  epithelium.  Whether  it  secretes  from  the 
vessels  under  it  the  plasma  from  which  the  epithelial  cells  are  de- 
veloped, is  uncertain.  This  has  been  supposed  to  be  the  fact ;  but 
this  supposition  is,  at  least,  quite  improbable. 

A  basement  membrane  is  said  by  some  to  exist  as  a  distinct 
structure  in  the  lining  membrane  of  the  bloodvessels  also.  This 
assertion  still  needs  confirmation,  though  the  presence  of  a  kind  of 
epithelium  there  suggests  the  idea  of  its  presence  also  from  analogy. 
Kolliker  asserts  the  contrary. 


112 


SIMPLE   HISTOLOGICAL   ELEMENTS. 


CHAPTER   III, 


SIMPLE   FIBRE. 


Fig.  48. 


Fibres  enter  into  the  composition  of  some  of  tlie  compound 
tissues ;  and  two  of  the  simple  tissues — the  white  and  the  yellow 
fibrous  tissues — are  formed  of  them  exclusively.  Simple  fibre  is, 
however,  something  entirely  different  from  these,  and  sustains  to 
them  no  higher  comparative  rank  than  do  the  lower  forms  of  ho- 
mogeneous substance  in  comparison 
with  ostein  e. 

An  example  of  simple  fibre,  always 
easy  to  obtain  for  illustration,  is  found 
in  the  membrane  lining  an  egg-shell 
(membrana  putarainis),  which  consists 
of  several  layers,  each  formed  by  the 
interlacement  of  simple  fibres.  (Fig. 
48.) 

Pure  coagulated  fibrine  also  consists 
merely  of  a  network  of  simple  fibres 
(p.  92). 
Simple  fibre  appears  always  to  consist  of  mere  threads  of  coagu- 
lated fibrine.     In  other  words,  it 


Simple  fibres  of  mcmbraue  lining  the 
CKg-shcU. 


Fig.  49. 


Simi'lij  fibres  in  i7illiiniiiiatciry 
jieriloiieum. 


•xiubilioii  from 


appears  to  be  merely  the  result  of 
the  fibrillation  of  fibrine  already 
described  (p.  93).  These  threads 
average  about  g^^j^  of  an  inch  in 
diameter.  Of  course  they  are  less 
perfectly  developed  in  the  cir- 
cumstances in  which  coagulation 
is  less  perfect  (p.  95).  On  the 
other  hand,  they  are  most  per- 
fectly developed  in  inflammatory 
exudations. 

The  human  chorion  appears  to 


SIMPLE   FIBRE. 


113 


be  formerl  at  first  exclusively  of  simple  fibres.  These,  however, 
subsequently  disappear,  as  its  development  proceeds. 

There  is  reason  to  believe  that  simple  fibres  constitute  the  matrix 
in  which  the  tissues  generally  are  developed  during  embryonic  life, 
as  well  as  the  nidus  in  which  repair  takes  place  after  solutions  of 
continuity  with  or  without  loss  of  substance  (p.  91). 

Uses. — Simple  fibre  is,  therefore,  not  a  permanent  constituent  of 
the  human  body.  It  must  be  regarded  as  a  merely  temporary 
element,  laid  down  as  a  framework  on  which  higher  histological 
elements  may  be  developed,  and  which  then  becomes  absorbed  and 
disappears. 

In  this  way,  however,  its  relations  to  the  tissues  are  all-important. 
Since,  also,  coagulated  fibrine  consists  of  a  network  of  similar  fibres, 
they  become  the  medium  for  the  spontaneous  arrest  of  hemorrhage, 
as  before  explained  (p.  91).' 

In  pathological  epigeneses  four  kinds  of  fibres  are  found  :  1. 
Cleavage  fibres^  by  far  the  most  common  of  all,  which  occur  in  in- 
flammatory exudations  after  coagula- 
tion ;  2.  Fibres  of  coagulation^  i.e.  formed 
by  fibrillation  of  fibrine,  as  occurs  in 
colloid ;  3.  Cell-fibres^  those  formed  in 
cells  (Fig.  50);  4.  Nuclear  fibres.,  those 
formed  of  elongated  nuclei  (Figs.  51 
and  174). 

The  first  two  forms  seem  identical 
with  simple  fibres.  Nuclear  fibres  are 
the  embryonic  form  of  the  yellow 
fibrous  tissue. 


Fig.  50. 


Fibre'-cells  passing  into  fibres. 


Fig.  51. 


Fig.  52. 


Nuclear  fibres. 


Simple  fibres  nnd  nurlei  in  false  membrane. 


'  The  elastic  spiral  fibre  in  the  trachere  of  insects  is  probably  mere  simple  fibre  ; 
and  the  fibre  found  in  the  air-vessels  of  plants  presents  a  similar  appearance, 
though  of  different  chemical  composition. 
8 


114 


SIMPLE    HISTOLOGICAL   ELEMENTS. 


That  fibres  of  any  kind  are  ever  formed  by  the  mere  conjunction 
of  nuclei,  must  be,  for  the  present,  regarded  as  very  improbable. 
Simple  fibres  are  found  as  a  permanent  development  in  some  false 
membranes,  so  called,  as  shown  by  Fig.  52. 


CHAPTER   lY, 


CYTOLOGY. —  CELLS. 


The  description  of  the  cells  (and  their  development  and  function), 
from  which  the  tissues  are  originally  formed,  constitutes  the  depart- 
ment of  histology  termed  Cytology.'  These  are  closed  vesicles, 
usually  of  a  globular  form,  varying  from  y^^  to  g^'^^  of  an  inch  in 
diameter,  and  consist  of  the  five  following  structural  elements: — 

1.  The  cell-wall. 

2.  A  contained  fluid. 

3.  Granules  floating  in  the  fluid. 

4.  A  nucleus. 

5.  A  nucleolus. 

Fig.  53. 


Cells  showing  the  cell-membrane,  the 
contained  granules,  the  nucleus,  and 
the  nucleolus.  1  and  2.  The  typical 
spherical  form.  The  rest  as  changed 
by  pressure. 


1.  The  cell-wall  is  formed  of  simple  membrane,  and,  of  course,  is 
an  albuminous  compound,  but  is  not  fibrine.  Though  varying  much 
in  thickness  in  different  instances,  it  presents  nothing  peculiar.  It 
is  generally  soluble  by  acetic  acid.  The  walls  of  epithelial  cells, 
however,  are  not  thus  dissolved  after  they  become  corneous,  though 


From  KuTo,-,  a  cavity  or  cell,  and  'Koyoq,  description. 


CYTOLOGY — CELLS.  115 

they  are  while  young ;  and  the  same  is  true  of  most  pathological 
cells.  The  wall  of  tlie  colored  blood-corpuscle  is  not  dissolved  by 
acetic  acid ;  but  most  observers  regard  these  bodies  as  nuclei,  and 
not  as  cells. 

2.  The  fiuid  contained  in  the  cells  is  almost  invariably  trans- 
parent, or  nearly  so.  In  the  blood-corpuscles,  however,  it  is  of  a 
bright  red  color.  In  chemical  composition  it  varies  extremely, 
being  usually  an  albuminous  compound — in  part,  at  least.  It  is 
not  so,  however,  in  the  epithelial  cells  of  glands ;  and  in  the  cells  of 
adipose  tissue  it  consists  of  margarine  and  stearine  dissolved  in 
oleine  (p.  76.)  The  cells  of  the  epidermis,  and  of  nails,  horn,  and 
hoofs,  contain  keratine  and  fat;  and  those  of  the  epithelium  on 
mucous  membranes  generally  contain  mucosine,  but  no  albumen. 

3.  The  granules  floating  in  the  fluid  contained  in  the  cells  are 
often  in  immense  number;  are  rounded  corpuscles,  so  minute  as 
hardly  to  admit  of  being  measured ;  and,  in  most  instances,  have 
no  investing  membrane.  This  is  the  case  with  the  fatty  granules 
in  many  cells  and  glandular  secretions,^  they  bemg  merely  fat-glo- 
bules. The  granules  giving  the  color  to  the  pigment-cells  have 
also  no  investing  membrane. 

In  other  cases  the  granules  have  an  investment,  and  are  termed 
elementary  vesicles  (more  properly  called  free  nuclei) ;  e.  g.  milk- 
globules  are  originally  such  granules  of  fat,  with  an  investment  of 
caseine  in  the  form  of  a  simple  membrane  (p.  89),  and  contained 
within  the  secreting  cells ;  and  the  molecules  floating  in  chyle  and 
blood  are  mere  fat-granules  with  an  albuminous  investment.   {Miil- 

T.  "Wharton  Jones  regards  the  colored  blood-corpuscles  of  man 
and  the  mammalia  as  elementary  vesicles,  or  free  nuclei,  except 
whUe  in  the  parent  cells  (the  colorless  corpuscles  of  the  blood)  in 
which  they  were  formed.  Xeither  of  these  two  kinds  of  floating 
granules  just  mentioned  (milk-globules  and  blood-corpuscles)  in- 
crease in  size  when  once  formed,  nor  do  they  multiply  by  subdi- 

'  As  the  granuLir  precipitates  of  the  coloring  matter  of  the  bile.  Add  to  these, 
also,  the  albuminous  granules  in  certain  portions  of  the  gray  substance  of  the 
cerebro-spinal  centre,  and  of  the  retina. 

2  Ascherson  discovered,  in  1840,  that  whenever  fluid  fat  and  fluid  albumen  are 
shaken  together,  the  fat-globules  thus  fonned  are  always  surrounded  by  an  albu- 
minous coat.  He  termed  this  the  haptogen  membrane.  It  is  the  result  of  mere 
chemical  action,  and  exhibits  no  vital  endowment  whatever. 


116 


SIMPLE    HISTOLOGICAL   ELEMENTS. 


vision  or  by  eudogenous  development.  {KoUiker,  p.  12.)  Thus  they 
incline  towards  merely  inorganic  forms,  as  produced  by  crystal- 
lization. 

It  should  be  added  that  in  some  cells  no  granules  exist,  but  only 
a  clear  fluid,  as  in  case  of  the  fat-cells  and  the  colored  blood-cor- 
puscles. 

4.  The  nucleus  is  a  globular  or  lenticular  body,  measuring  from 


eu'ou 


to 


3l)Oi5 


of  an  inch.'  It  is  attached  to,  or  imbedded  in,  the 
wall  of  the  cell,  except  in  case  of  the  free  nuclei  already  mentioned, 
which  have  escaped  from  the  parent  cell,  and  have  no  nucleoli;  and 
is  transparent  and  of  a  yellowish  color.  All  nuclei  are  themselves 
vesicles.  The  contents  are,  besides  a  nucleolus  usually  present, 
almost  invariably  a  yellowish  or  transparent  fluid;  and  in  this  both 
water  and  acetic  acid  precipitate  the  same  dark  granules  which  are 
found  floating  in  the  cells. 

Acetic  acid,  however,  renders  the  nucleus  more  visible,  while  it 
dissolves  the  cell-wall.  But  the  pus-corpuscle^  which  Gluge  incor- 
rectly regards  as  a  mere  nucleus,  is  dissolved  by  this  acid. 

Sometimes  this  vesicle  (the  nucleus)  contains  formed  granules, 
as  the  spermatic  filaments  (spermatozoids)  in  semen  (Fig.  54),  and 
peculiar  granules  (germinal  spots)  in  ova  (Fig.  55).  The  germinal 
spot  is  actually  a  nucleolus  within  the  germinal  vesicle,  the  latter 
being  the  nucleus  of  the  ovum. 


JFig.  54. 


Fig.  55. 


Spermatozoids.   1  to  4.  Their  variety 
in  form.  S.  Seminal  granules. 


Oerminal  spot,  &c.,  of  ovum.  1.  Stroma  of  tlio  ovary.  2and 
.3.  External  auJ  internal  tunics  of  the  Graafian  vesicle.  4. 
Cavity  of  the  latter,  .'i.  Tliick  tunic  of  the  ovum,  or  yolk-sac. 
C.  Tlio  yolk.    7.  Tho  germinal  vesicle.    8.  The  germinal  spot. 


'  It  sometimes  moasures  even  from  y^'an  ^'^  c.'o  '^^  ^"^  inch,  as  in  ganglion-cells 
and  ova. 


NUCLEI.  117 

The  membranous  wall  of  the  nuclei  is  certainly  an  albuminous 
compound,  and  probably  but  little,  if  at  all,  different  from  the 
younger  cell-membranes.  Generally  the  granules  within  it  are  mere 
globules  of  fat,  like  those  floating  in  the  cell. 

Nuclei  are  found  in  all  cells  of  embryos,  and  in  adults  also  while 
the  cells  are  still  young ;  though  in  some  cases,  as  in  the  fat-cell, 
they  subsequently  disappear. 

Generally  but  a  single  nucleus  exists  in  each  cell ;  but  when  a 
cell  is  multiplying,  as  many  nuclei  arise  as  there  are  new  cells  to  be 
formed. 

In  some  cases,  however,  several  nuclei  naturally  exist ;  four,  ten, 
twenty,  or  even  more,  nuclei  being  found  in  the  same  cell.  This  is 
especially  the  case  with  cancerous  and  other  rapidly  developed  ma- 
lignant growths. 

Free  nuclei  also  take  part  in  the  formation  of  certain  tissues — as 
in  the  rust-colored  layer  of  the  cerebellum,  and  in  the  granular 
layer  of  the  retina. 

Thus  a  nucleus  is,  histologically,  an  embryo  cell. 

Pathological  Developments  of  Nuclei. 

1.  The  characteristic  structure  of  tubercle — tubercle-corpuscles — 
consists  of  mere  nuclei  inclosina:  nucleoli,  there  beino;  uo  cells  in  this 
deposit.  The  other  element  of  tubercle  is  an  amorphous,  semi-solid 
hyaline  substance,  which,  in  the  opaque  or  yellow  variety,  but  not 
in  the  gray  or  transparent  tubercle,  contains  granules  also  (p.  108). 

The  nuclear  bodies  of  tubercle  are  usually  oblong,  polyhedral, 
averaging  ggVi  of  ^^^  i^^ch  long,  and  45*45  of  an  inch  wide.  They 
consist  (i)  of  a  delicate  transparent  membrane,  with  (2)  a  transpa- 
rent, colorless,  or  faintly  ambreous  fluid,  containing  (3)  granules,  and 

Fig.  56.  Fig.  57.  Fig.  58. 


0m)' 


s^mmi 


Ml 


Fig.  .'JC.  Tubercle-corpuscles  frem  peritoneum.  Those  at  the  right  show  the  eifccfs  of  acetic  acid. 
Fig.  57.  Tubercle-corpuscles  aud  granular  homogeneous  substance  from  lung.  Fig.  5S.  Tubercle- 
corpuscles  from  mesenteric  gland.    Free  oil-globules  are  seen  at  the  right  in  Fig.  57. 


lis  SIMPLE   HISTOLOGICAL   ELEMENTS. 

(4)  two  or  three  to  a  dozen  scattered,  globular,  transparent  nucleoli. 
(Figs.  56,  57,  and  58.) 

Tubercle-corpuscles  are  distinguished  from  those  of  pus,  from 
being  smaller,  less  granular,  and  not  having  their  nucleoli  aggre- 
gated. Acetic  acid  also  slightly  affects  their  nucleoli;  while  it  must 
often  be  applied  to  the  nucleoli  of  pus-corpuscles,  to  render  them 
visible.  The  peculiar  nuclei  of  cancer  are  distinguished  from  those 
of  tubercle  by  being  larger,  regularly  oval,  or  not  un frequently 
spherical,  and  from  containing  only  one  or  two  nucleoli. 

As  seen  under  the  microscope,  typhous  and  scrofulous  deposits 
are  not  to  be  distinguished  from  tubercle. 

Chemical  analysis  of  the  solid  matter  of  tubercle  gives  the  follow- 
ing result.  (Preuss.)  Scherer,  however,  finds  that  tubercle  varies 
much  in  composition  in  different  cases. 

1.  Matters  soluble  in  hot  alcohol. 
Cholesterine 4.94 

2.  Hatters  soluble  in  cold  alcohol,  but  not  in  icaier. 
Oleate  of  soda      ......       13.50 

3.  Matters  soluble  in  dilute  alcohol. 
A  peculiar  substance  ) 

Lactate  and  sulphate  of  soda  >•    .         .         .         8.46 
Chloride  of  sodium  ) 

4.  Matters  soluble  in  ivater. 
Caseine^  ] 

Sulphate  and  phosphate  of  soda   I       .         .         7.90 
Chloride  of  sodium  ) 

5.  Matters  insoluble  in  cold  ivater  and  cdcohol. 
Caseine^  altered  by  heat  \ 

Phosphate  and  carbonate  of  lime  v      .       65.11 

Oxide  of  iron,  magnesia,  and  sulphur  ) 

99.91 

In  cretaceous  transformation  of  tubercles,  the  salts  of  lime  espe- 
cially become  increased.  The  small  amount  of  fat  existing  in  tu- 
bercle has  already  been  alluded  to  (p.  78).  In  a  gray,  well-dried 
tubercular  mass,  Lehmann  found  but  3.54  per  cent,  of  fat.  The 
cholesterine  should  not  be  regarded  as  fat. 

2.  The  exudation- corpuscle  (inflammation-corpuscle  of  Gluge)  con- 
sists of  a  group  of  ten  to  forty  or  more  granules,  held  together  by 
a  coagulated  albuminous  matter,  soluble  in  acetic  acid.  These  mul- 
berry-like bodies  are  also  called  granule-cells  and  (jlomernli. 

They  measure  from  j^'^g  to  gj^  of  an  inch  in  diameter.     They 

'  An  albuminous  comjiouml,  but  not  caseine.   (Ze/u/ia/in.) 


NUCLEOLI.  119 

are,  however,  not  peculiar  to  inflammation,  but  appear  in  the  colos- 
trum and  in  the  ogg.  They  are  regarded  as  free  nuclei,  and  are 
represented  by  Fig.  59. 

Fig.  59. 
1  2  3 


4R     , 


Olomeruli  and  granular  cells.     The  dark  cells  are  the  gloraerali.     1.  From  inflamed  lung.     2.  From 
inflamed  pia  mater.     3.  From  tubercular  meningitis. 

5.  The  nucleolus  is  a  round,  sharply  defined,  fat-like  granule, 
generally  of  a  dark  color,  and  measuring  i2i)^c  ^^  ffAo  of  ^'i^  inch^ 
in  diameter.  It  is  inferred  that  they  are  vesicular,  from  their 
sharply  defined  form,  from  their  similarity  to  free  nuclei,  and  from 
the  fact  that,  when  large,  a  cavity  filled  with  fluid  frequently  be- 
comes developed  in  them.     Acetic  acid  does  not  dissolve  them. 

They  are  believed  to  be  constituted  of  fat,  with  an  albuminous 
compound  for  the  investing  membrane. 

Nucleoli  are  generally  found  in  nuclei  while  still  young,  and  in 
many  during  their  whole  existence.  Still,  they  cannot  be  regarded 
as  an  essential  constituent  of  the  cell,  like  the  nucleus,  since  they 
cannot  always  be  with  certainty  recognized  in  the  latter.  Cells 
without  nuclei,  of  course,  have  no  nucleoli. 

Usually  but  one  nucleolus  is  found  in  a  nucleus,  but  frequently 
there  are  two ;  and  in  solitary  cases  four  or  five  may  be  found, 
which  then  are  either  eccentric,  or  lie  free  in  the  nucleus. 

A  nucleolus  is,  therefore,  histologically,  an  undeveloped  nucleus ; 
and  since  both  nucleoli  and  nuclei  contain  fat,  and  the  free  granules 
in  cells  consist  of  it  usually,  in  part  at  least,  fat  is  always  indis- 
pensable in  the  plasma  from  which  cells  are  developed.  On  the 
other  hand,  there  is  no  evidence  that  fihrine  exists  in  the  cell-wall 
or  the  contained  fluid.  All  agree  that  the  former  is  an  albuminous 
substance. 

That  fibrine,  therefore,  is  the  only  plastic  element  in  the  blood,  is 
highly  improbable.  The  remark  of  Gluge,  that  "  the  formation  of 
fibres  and  cells  from  fibrine  is  a  matter  of  direct  observation,"^ 

'  In  ganglion-cells,  and  in  tlie  germinal  spots  of  ova,  tliey  sometimes  measure 
4(i'(5(r  to  Ts'».j  of  an  inch. 
'  Pathological  Histology,  p.  50. 


120  SIMPLE    HISTOLOGICAL   ELEMENTS. 

might  seem  to  settle  this  question  otherwise;  but  it  apparently 
does  not  occur  to  this  observer  that  the  plasma  under  his  micro- 
scope is  not  fibrine  alone,  but  the  liquor  sanguinis,  and  therefore 
only  about  jic  part  fibrine. 

Hence,  while  the  formation  of  fibres  and  cells  is  a  matter  of  direct 
observation,  the  assertion  that  cells  are  formed  from  fibrine  is  a 
mere  assumption,  which  we  cannot  accept  even  on  this  high  autho- 
rity without  proof.  This,  up  to  the  present  time,  is  entirely  want- 
ing. All  the  facts  hitherto  presented  point,  on  the  other  hand,  to 
the  inference  that  the  albumen  of  the  blood,  and  not  the  fibrine,  is 
the  pabulum  of  the  cells  whose  structure  and  composition  have  just 
been  specified.     (See  also  pp.  86  and  91.) 

Development  of  Cells  {Cytogeny^). 

Cells  are  developed  in  two  ways — 

I.  Directly  from  the  plasma  (p.  95,  X.),  without  the  aid  of  a  pre- 
existing cell :  free  cell-development. 
II,  From  other  cells. 

A.  Within  them:  endogenous  cell-development. 

B.  By  their  subdivision  into  two  or  more  cells:  Jissiparous 

cell-development. 

I.  Free  Cell-development. 

Free  cell-development  occurs  in  the  case  of  the  chyle  and  lymph- 
corpuscles,  of  the  cells  of  certain  glandular  secretions,  of  the  sperm- 
atic cells,  of  ova,  the  cells  in  the  closed  follicles  of  the  intestine  and 
of  the  lymphatic  glands,  and  in  the  corpuscles  and  pulp  of  the 
spleen. 

The  nucleus^  of  a  cell  is  always,  according  to  most  observers,  the 
part  first  developed.  Granules  first  appear  in  the  clear  plasma, 
some  of  which  increase  in  size,  and  assume  the  form  of  a  minute 
vesicle,  the  nucleus  of  the  future  cell.  On  the  addition  of  water  to 
this,  granules  become  apparent  in  its  interior,  and  one  of  these, 
larger  than  the  rest,  appears  to  be  the  nucleolus.     Around  the  nu- 

'  From  xJto;,  a  cell,  and  ye'vof,  descent,  production. 

^  Hence  the  nucleus  is  sometimes  termed  a  ctjtohlast — i.  e.  a  cell-germ — from 
jtirof,  cell,  and  Sxacroi;,  a  germ  or  shoot. 

The  word  cytollastema  is  also  apjilied  to  the  fluid  in  and  from  which  the  cells  are 
formed.     Blastema  means  the  materials  from  which  germs  are  developed. 


DEVELOPMENT   OF   CELLS.  121 

cleus,  as  is  generally  stated,  tlic  cell-membrane  is  developed,  and 
thus  the  cell  is  completed. 

But,  admitting  the  preceding  account  to  be  correct  in  particular 
cases,  another  explanation  of  the  process  certainly  applies  in  some, 
and,  it  is  believed,  in  most  instances.  It  is  thus  expressed  by  Dr. 
Burnett  as  being  usual  in  animal  tissues,  at  least : — 

1.  A  primordial  utricle  appears  in  the  clear  plasma. 

2,  It  expands  into  a  clearly  seen  vesicle. 

8,  A  partial  condensation  occurs  of  its  liquid  contents  towards 
the  centre,  giving  rise  to  a  new  utricle,  constituting  the  nucleus; 
the  whole  thus  forming  the  complete  nucleated  cell.^ 

When  we  consider  that  the  nucleus,  the  nucleolus,  and  the  primary 
utricle  are  all  vesicles,  or  minute  cells  already  formed,  we  may  well 
admit  that  either  the  utricle  or  the  nucleus  may  be  first  formed,  and 
in  time  become  a  larger  cell;  and  it  still  admits  of  question  whether, 
in  the  last  instance,  the  cell  is  not  formed  by  mere  enlargement  of 
the  nucleus,  instead  of  around  it.  But,  doubtless,  a  cell,  while  being 
developed,  may  also  develop  a  nucleus  within  it,  precisely  as  a 
nucleus  develops  within  itself  a  nucleolus. 

The  most  satisfactory  view  of  the  subject  appears  to  be  the  fol- 
lowing ;  it  being  understood  that  only  those  cells  are  now  under 
consideration  which  are  formed  in  a  clear  plasma,  and  not  those 
formed  from  other  cells. 

No  sufficient  reason  appears  why  a  primary  utricle  may  not  be, 
in  all  cases,  as  easily  formed  in  a  clear  plasma  as  a  nucleus  can; 
and  if  this  becomes  a  cell  in  one  instance,  and  then  forms  a  nucleus 
within  itself,  it  is  hardly  probable  that  a  nucleus,  on  the  other  hand, 
is  first  formed  in  other  instances,  and  then  forms  a  cell  around  itself. 
It  is  far  more  probable  that  the  first  cells  are  formed  in  a  clear 
plasma  without  the  aid  of  a  nucleus,  they  being  merely  fully  de- 
veloped primary  utricles;  true/ree  ce?Z-formation  always  proceeding 
in  this  way.  The  second  generation  of  cells  may  be  formed  from 
the  nuclei  in  the  first,  or  not;  but,  if  so,  it  is  endogenous  formation, 
and  not  the  form  of  development  here  under  consideration.  If  all 
the  cells  of  any  given  kind  are  to  be  formed  by  free  cell-develop- 
ment, however  (as  the  chyle-corpuscles),  then  we  see  no  advantage 
at  all  in  their  containing  nuclei.  The  fact  that  any  cell  contains  a 
nucleus  evinces  a  power  of  producing  another  cell  by  endogenous 

'  Prize  Essay,  Transactions  of  the  American  Medical  Association,  vol.  vi.  p.  SGI. 


122  SIMPLE   HISTOLOGICAL   ELEMENTS. 

formation ;  though  here,  also,  it  may  still  be  a  question  whether  the 
nucleus  itself  becomes  the  future  cell,  or  whether  it  forms  the  new 
cell  around  itself,  as  is  generally  asserted.* 

If,  in  any  case,  but  a  single  generation  of  cells  is  required,  for 
the  reason  that  the  original  ones  are  to  remain  unchanged  in  the 
organism,  no  nuclei  are,  of  course,  needed,  if  we  still  maintain  that 
the  nucleus  exists  merely  to  develop  another  cell.  Some  have 
placed  the  fat-cells  in  this  category,  though  incorrectly,  as  will 
appear.    (Chap.  V.) 

In  the  ovum  alone  (so  far  as  is  known)  a  layer  of  semi-solid 
plasma  is  interposed  between  the  nucleus  and  the  cell-membrane, 
and  entirely  incloses  the  former.  (Fig.  55.) 

In  patliological  productions,  free  cell-development  is  very  common. 
Pus-cells  and  exudation-cells  (or  corpuscles)  are  thus  formed.  This 
method  of  development  of  epithelial  cells,  and  of  those  of  which 
nails  and  horn  are  formed,  is,  however,  rather  assumed  by  authors 
than  established  by  proof. 

II.  Development  of  Cells  from  pre-existing  Cells. 
A.  Endogenous  Cell-development. 

The  most  frequent  form  of  endogenous  cell-development  is  that 
in  which  two  secondary  cells  are  produced  within  the  original  one. 
Here,  in  the  first  place,  the  nucleus  of  the  parent  cell  enlarges,  and 
exhibits  two  nucleoli ;  then  it  becomes  elongated,  and  constricted 
in  the  middle,  and  at  last  separates  into  two  portions.  Each  of 
these  becomes  the  nucleus  of  a  new  cell,  and  the  two  nucleated  cells 
thus  formed  at  length  fill  up  the  interior  of  the  parent  cell.  (Figs. 
60  and  61.)  The  parent  cell  may  burst  and  set  free  the  secondary 
cells,  or  continue  to  enlarge  till  several  generations  have  been  thus 
developed  within  it.  On  the  other  hand,  it  may  coalesce  with  the 
substance  which  unites  the  cells  as  a  matrix. 

This  mode  of  development  in  persistent  parent  cells^  occurs  in  the 
cartilages  of  all  young  animals,  and  very  probably  during  the  de- 
velopment of  the  tissues  generally,  in  their  embryonic  state.  (Kol.) 

Thus  the  nucleus  existing  in  a  cell  is  the  germ  which  is  to  be 
developed  into  the  cell  of  the  next  generation — that  of  which  the 

'  Tho  blind  adiierenco  liitlierto  to  the  observations  upon  cell-development,  of 
Schwann  and  Schleiden,  has  retarded  the  progress  of  histological  science,  and  the 
whole  subject  demands  investigation  de  novo. 

^  Cavities,  rather.     See  Chap.  VL 


DEVELOPMENT   OF   CELLS, 


123 


first  is  the  parent;  while  the  nucleolus  bears  the  same  relation  to 
the  nucleus  that  the  last  does  to  the  original  cell,  i.  e.  it  is  to  be  de- 
Fig.  60. 


Fig.  61. 


Endogenous  cell-dovelopment.     A,  b,  c,  d.   Early  stages  of  the  process  (ovum  of  Asearis  dentata). 
E,  F,  «,  H.  More  advanced  stages  (ovum  of  Cucullanus  eleffans). 

veloped  into  the  third  generation — the  cell  of  which  the  second  is 
the  parent.  While  the  nucleus  is  forming,  it  develops  within  itself 
the  nucleolus;  and  while  it  is 
becoming  the  second -genera- 
tion cell,  the  nucleolus  becomes 
a  nucleus,  and,  in  its  turn,  Torms 
a  nucleolus  within  itself.  Thus 
the  nucleus  itself  becomes  the 
next  cell,  though  it  is  not  here 
asserted  that  it  in  no  case  forms 
a  cell  around  itself.  Hence,  also, 
if  a  cell  has  never  contained  a 
nucleus,  it  is  itself  called  a  free 
nucleus^  as  we  have  seen,  or  an 
elementary  vesicle.  It  is  not, 
physiologically,  a  cell,  and  has 
no  power  of  multiplication. 
Such  are  the  corpuscles  of  tu- 
bercle, ana   toe  colored,  corpus-  Endogenous  cell-growth    (meliccrifious  tumor). 

CleS  of  the  blood  (p.  115).    These     "■   ^'"'  ^'^^  ""'^'^  variously  developed,     b.  Pa- 
^  ^    _  rent  cell  filled  with  young  cells,  which  have  ori- 

may    or    may    not    contain    nu-     giuatod  from  the  granules  of  the  nucleus. 


124 


SIMPLE   HISTOLOGICAL   ELEMENTS. 


Fiff.  62. 


Segmentation  of  the  vitellus 
(yolk)  of  the  mammalian  ovum. 
A.  Its  first  division  into  two 
halves.  B.  Subdivision  of  each 
half  into  two.  c.  Further  sub- 
division, producing  numerous 
segments. 


cleoli,  and  are  developed  either  in  a  plasma 
or  within  pre-existing  cells. 

In  the  fecundated  ovum  the  formation  of 
cells  is  preceded  by  a  peculiar  process — the 
cleavage  or  segmentation  of  the  yolk — which 
is  introductory  to  an  endogenous  cell-deve- 
lopment. The  nucleus  of  the  parent  cell  {i.  e. 
the  germinal  vesicle),  Fig.  55,  disappears  after 
fecundation,  and  the  granules  become  dispers- 
ed and  fill  the  whole  cell.  Another  nucleus  is 
then  developed  around  a  nucleolus,  and  the 
yolk  forming  around  it,  in  a  globular  form, 
constitutes  the  first  cleavage-mass.  From 
this  nucleus  two  others  are  formed,  as  before 
described,  and  then  two  cleavage-masses  re- 
sult; and  thus  the  multiplication  proceeds 
till  the  cavity  of  the  yolk  is  filled  with  small 
globules.  Lastly,  the  latter,  either  together 
or  in  successive  layers,  are  surrounded  with 
investing  membranes,  and  thus  become  per- 
fect cells — the  parent  cell  still  persisting, 
and  inclosing  them.  Figs.  62  and  63  illus- 
trate this  process,  and  also  show  spermato- 
zoids  on  the  outer  surface  of  the  vitellus  or 
yolk. 

Generally,  the  development  of  a  large 
number  of  cells  within  a  single  parent  cell 
occurs  only  in  structures  of  a  rapid  growth. 


Fig.  63. 


Sogmontation  of  the  yolk— latter  stages.  A.  The  •'  mulberry -mass"  from  the  minute  subdivision 
■>f  the  vitelline  spheres.  At  b  it  has  come  into  contact  with  the  vitelline  membrane,  against  which 
the  aphorules  are  flat'.eued. 


DEVELOPMENT   OF   CELLS. 


m 


which  do  not  form  a  permanent  part  of  the  organism ;  such  as 
granulations  and  cancerous  or  other  malignant  growths  which 
undergo  a  speedy  degeneration.  (Fig.  64.) 


Fig.  64 


Colls  (aud  fibres)  from  eacephaloid  of  tongue,  growing  rapidly 


One  of  the  hepatic  coeca  of 
the  cray-fish  (Astaous  affinis), 
showing  the  progressive  deve- 
lopment of  the  secreting  cells 
from  the  nuclei  at  its  bottom. 
The  stages  are  shown  by  the 
letters  a  to  e. 


The  vital  force  is,  as  it  were,  exhausted 
by  this  rapid  multiplication,  so  that  the  cells 
thus  formed  are  incapable  of  further  deve- 
lopment, while  the  slow  method  by  duplica- 
tion may  proceed  to  any  extent.  In  glandu- 
lar follicles,  however,  this  rapid  multiplication  of  cells  "may  often 
be  recognized,"  for  each  of  the  terminal  coeca  or  follicles  is  regarded 
as  a  single  parent  cell  with  a  persistent  nucleus  (germinal  centre) ; 
and  it  appears  that  the  materials  of  secretion  are  eliminated  from 
the  blood  by  the  continual  development  of  young  cells  from  this 
nucleus.  (Fig.  65.) 


B.  Fissiparous  Cell-develojy/nent,  of  that  hy  Division. 

In  the  multiplication  of  cells  by  division,  the  original  cell  first 

becomes  elongated,  and  two  nuclei  are  developed  from  the  original 

nucleus,  by  division,  apparently,  as  before  described.    The  cell  then 

becomes  constricted  at  the  middle,  and,  the  nuclei  receding  from 


126 


SIMPLE   HISTOLOGICAL   ELEMENTS. 


Fig.  66. 


each  other,  it  finally  separates  into  two  distinct  nucleolated  cells. 

In  the  blood-corpuscles  of  the  chick,  all  the  stages  of  this  process 

can  be  readily  observed. 

This  development  of  cells  by  bipartite 
division  occurs  in  the  red  blood-cor- 
puscles of  the  embryos  of  birds  and 
mammalia,  and  in  the  fi.rst  colorless  cor- 
puscles of  the  tadpole.  (Fig.  66 )  It  also 
occurs,  probably,  in  the  colorless  blood- 
corpuscles  of  the  human  embryo,  and, 
sometimes  at  least,  in  the  chyle-cor- 
puscles of  adult  animals.  [KoUiker.) 
It  is  also  constantly  observable  in  the  development  of  cartilage 

(Figs.  67  and  46),  and  here  the  division  may  be  bipartite,  tripartite, 

or  even  tetrapartite. 


Blood-corpuscles   multiplying  by  bi 
partite  division.   {KMiker.) 


?^.' 


/i^ 


Multiplication  of  cartilage-colls  by  division. 


The  Physiology  of  Cells. 
Under  this  head  will  be  considered — 

A.  The  growth  of  cells. 

B.  Their  physiology  proper,  including  the  nature  of  their  contents, 

and  the  processes  performed  by  them. 

A.  The  Growth  of  Cells. 
Growth,  doubtless,  occurs  in  all  cells,  to  some  extent.    It  is,  how- 
ever, most  manifest  in  cases  when  the  cell-membrane  is  formed 


PHYSIOLOGY   OF   CELLS.  127 

directly  around  the  nucleus.  But  cells  wLicli  from  the  first  have 
contents  (the  ccU-inembrane  in  these  cases  forming  around  masses 
investing  the  nucleus),  increase  very  slightly  in  size. 

The  nucleus,  and  nucleolus  also,  usually  increase  in  size  with  the 
cell ;  but  the  nucleoli  always  retain  their  globular  form,  except 
when  dividing  fissiparously. 

In  cell-growth  there  is  an  increase  either  of  the  surface  or  of  the 
thickness  of  the  cell-wall,  and  this  increase  may  be  either  general 
or  partial.  It  is  general  when  the  cell  grows  larger  without  change 
of  form;^  partial  when  the  cell  changes  its  form  by  extending  itself 
at  two  or  more  points.  Carpenter  thinks  this  extension  takes  place 
in  the  direction  of  the  least  resistance ;  but  its  cause  is  not  demon- 
strated. In  some  cases  the  cell  becomes  narrower  as  it  elongates ; 
and  here  we  must  admit  that  absorption  occurs  in  one  direction 
while  deposition  goes  on  in  the  other. 

The  power  of  growth  does  not  appear  to  be  simply  innate  in 
every  organic  membrane,  and  therefore  manifesting  itself  whenever 
formative  material  is  presented,  but  it  requires  certain  conditions 
which  the  cell-membrane  alone  affords.  The  nuclei,  when  free, 
never  grow  to  any  considerable  extent,  and  especially  not  in  one 
particular  direction.^ 

B.  The  Nature  of  the  Contents^  and  the  Functions  of  Cells. 

Usually  the  contents  of  a  cell  may  be  regarded  as  a  "moderately 
concentrated  solution  of  albuminous  elements  with  alkaline  and 
earthy  salts,  and  dissolved  or  suspended  fatty  particles."  Different 
cells,  however,  differ  greatly  in  this  respect ;  some  one  of  these  con- 
stituents greatly  predominating  in  some,  while  in  others  altogether 
different  substances  may  be  found.  The  nerve-cells  abound  in  albu- 
minous elements ;  adipose  cells,  and  those  of  the  sebaceous  follicles 
and  of  milk-glands,  in  fat;  while  in  certain  other  cells,  hasmatine, 
melanine,  or  biliary  or  urinary  constituents,  abound. 

l^hQ  functions  performed  by  cells,  as  inferred  from  the  phenomena 
manifested  by  their  contents,  may  be  specified  under  the  heads  of 

•  According  to  Schwann,  the  cell-membrane  exerts  an  attractive  influence  upon 
the  surrounding  fluid,  and  causes  the  deposition  of  newly  formed  particles  in  its 
substance  ;  and  partial  growth  occurs  when  the  molecules  do  not  all  attract  equally, 
but  only,  or  more  particulai'ly,  at  certain  jioints. 

^  The  nuclei  in  the  hair-pulp,  tooth-pulp,  areolar  tissue,  and  smooth  muscular 
fibre,  however,  grow  in  one  direction,  to  a  considerable  extent,  these  not  being  free. 


128  SIMPLE   HISTOLOGICAL   ELEMENTS. 

absorption^  secretion^  and  contraction.  These  vital  actions  depend 
mucli  on  physical  and  chemical  conditions,  and  may,  to  a  great 
extent,  be  subjected  to  microscopic  investigation. 

1.  Absorption  must  be  distinguished  from  mere  endosmosis,  since 
the  nutrition  of  the  cell  (a  vital  and  not  a  mere  physical  process), 
depends  on  the  former,  and  some  of  the  constituents  of  the  sur- 
rounding fl'uid  are  introduced  through  the  cell-membrane,  while 
the  rest  are  rejected.  Thus  the  contents  of  all  cells  are  chemically 
diflfereut  from  the  surrounding  cytoblastema.  For  instance,  the 
blood-corpuscles  contain  more  potassa  than  the  liquor  sanguinis. 
Doubtless  the  chemical  composition  of  the  cell-contents  and  the 
surrounding  fluid,  and  the  thickness  of  the  cell-membrane,  also 
exert  an  influence  on  this  process;  nor  must  endosmosis  be  entirely 
overlooked  in  this  connection,  since  cells  are  known  to  dilate  in 
diluted,  and  to  contract  in  concentrated  solutions. 

The  vital  processes  in  cells  produce  changes  both  in  their  walls 
and  in  their  contents.  The  membranes  generally  become  denser, 
and  of  a  different  chemical  constitution,  with  age ;  though  whether 
the  membrane  itself  changes  chemically,  or  an  incrustation  of  salts 
occurs  within,  or  a  deposit  on  the  exterior,  are  points  not  con- 
clusively settled. 

The  changes  in  the  coW-contents  are  various.  Tlie  primordial  cells 
of  the  embryo,  at  first  distended  with  the  elements  of  the  yolk, 
especially  with  oil,  gradually  acquire  more  fluid  and  homogeneous 
contents,  the  granules  becoming  dissolved.  Then,  as  development 
proceeds,  various  new  formations  appear  in  the  cells,  as  hoematine, 
melanine,  fat,  &c.  But  changes  in  cell-contents  occur  in  aclult  ani- 
mals also.  Fat-cells,  in  great  deficiency  of  their  nutritive  elements, 
may  lose  their  proper  contents,  and  contain  mere  serum;  or,  in  case 
of  a  superfluity  of  nutriment,  they  may  even  burst  from  fulness.* 

The  lymph-corpuscles  also  develop  the  coloring  matter  of  the 
blood  and  the  colored  corpuscles,  within  them ;  and  the  cells  which 
secrete  the  bile  undergo  marked  changes  in  their  contents.  {Kulh'ker.) 

Changes  in  the  form  of  the  cells  accompany  the  preceding  altera- 

'  Donders  has  ascertained  that  the  cell-membranes  are  elastic,  and  the  contents 
will  suffer  a  greater  or  a  less  pressure,  according  to  their  amount.  This  elasticity 
may  conduce  to  the  maintenance  of  a  regular  interchange  of  substances  in  the  ex- 
cretive and  absorptive  processes.  And  the  greater  density  of  the  cell-contents  than 
of  the  surrounding  cytoblastema  may  be  due  to  the  fact  that  they  are  always 
under  greater  pressure. 


PHYSIOLOGY   OF   CELLS.  129 

tions  in  the  contents,  such  as  thickening  of  the  membrane  Avith 
laminated  depositions,  as  in  cartilage,  and  with  the  formation  of 
minute  canals;  while  within,  also,  the  granules  may  be  precipitated, 
fat-drops,  elementary  vesicles,  concretions,  crystals,  or  nuclei  may 
be  formed,  and  molecular  movements  may  occur. 

The  nuclei  rarely  participate  in  these  changes,  though  they  some- 
times become  clear  in  consequence  of  the  liquefaction  of  their  viscid 
contents.  Very  rarely  granules  are  developed  in  them ;  and  in  cer- 
tain animals,  "urticating  threads"  and  spermatozoids  are  developed 
in  nuclei.' 

2.  The  process  of  secretion  is  manifested  by  cells  in  two  ways: — 

First.  Their  contents  consist  of  substances  received  from  with- 
out, unaltered,  or  slightly  so;  as  in  case  of  epithelium-cells,  espe- 
cially of  serous  membranes,  and  the  cells  of  those  glands  which 
simply  separate  certain  substances  from  the  blood — e.  g.  the  lachry- 
mal glands  and  the  kidneys.  {KoUiker.) 

Secondly.  The  cell-contents  include  substances  prepared  within 
the  cell ;  as  the  colored  blood-corpuscles,  fat-cells,  the  bile-cells  in 
the  liver,  and  those  (secreting  the  gastric  fluid)  of  the  gastric  glands. 

8.  Contraction  is  sometimes  manifested  by  cell-membranes  and  by 
the  cell-contents.  Contractile  cell-membranes  occur  in  many,  if  not 
all,  of  the  Protozoa,  in  the  yolk-cells  of  the  Planarise,  in  the  heart- 
cells  of  many  embryos,  &c.  Some  consider  that  the  colorless  cor- 
puscles of  man,  the  frog,  and  the  skate,  mucus-corpuscles,  and  the 
cells  in  the  meshes  of  the  areolar  tissue  of  the  disk  of  the  medusa, 
are  contractile  cells.^ 

Contractile  cell-contents  are  found  in  the  fibre-cells  of  smooth 
muscle,  in  the  stellate  cells  of  the  skin  of  the  embryo  Umax,  and  in 
striped  muscular  fibre. 

Certain  important  changes  in  the  cell-contents  occur  in  patholo- 
gical conditions.  Besides  those  already  specified,  the  following  may 
be  noted  here : — 

1.  Fatty  degeneration  is  the  most  common  change  in  cell-contents, 
more  or  less  fat-drops  accumulating  in  the  cell.  But  it  must  be 
borne  in  mind  that  the  cells  in  certain  parts  and  organs  normally 
contain  a  few  fat-globules. 

'  Thus  it  is  very  certain  th.at  the  raolecuLir  and  chemical  changes  of  the  cell- 
membrane  and  the  nucleus  are  independent  of  each  other. 

^  Bonders,  however,  maintains  that  the  cell-contents  only  (and  not  the  cell- 
membrane)  are  contractile. 

y 


130  SIMPLE   HISTOLOGICAL   ELEMENTS, 

2.  The  fatty  degeneration  may  pass  into  the  pigmentary ;  which 
may  also  occur  spontaneously.  Here  the  coloring  matter  generally 
passes  from  deep  yellow  to  brownish  black. 

8.  Dropsy  of  cells  occurs  if  the  blood  contains  an  undue  amount 
of  water.    [Wedl^ 

4.  Crystals  form  in  cells  from  the  absorption  of  the  watery  por- 
tion of  the  cell-contents. 

5.  Atrpphy  or  involution  {Wedl)  of  cells  may  occur,  in  conse- 
quence of  a  diminished  supply  of  nutrient  fluid. 

Primordial  Cells. 

Schwann  discovered  that  all  the  tissues  of  animals/  as  well  as  of 
plants,  are  developed  originally  from  nucleated  cells ;  and  to  these 
the  name  of  primordial  cells  has  been  given.  They  present  nothing 
peculiar  in  their  microscopic  appearance,  however ;  containing  the 
five  elements  already  mentioned  as  usually  characterizing  a  cell  (p. 
114).  We  find  in  the  embryo  a  mass  of  cells,  for  instance,  which 
are  to  develop  bone;  another  to  form  muscle;  a  third,  fibrous  tissue, 
&c.  But  though  the  microscope  does  not  enable  us  to  detect  any 
original  difference  in  them,  their  vital  properties  must  differ,  as  the 
developmental  result  demonstrates. 

Schwann's  assertion,  however,  applies  only  to  the  tissues  proper, 
and  not  to  the  simple  histological  elements  already  described. 
Simple  fibre  and  simple  membrane  are,  for  example,  lower  develop- 
ments than  cells,  and  are  not  formed  from  the  latter.  On  the  con- 
trary, cells  have  their  walls  formed  of  simple  membrane,  as  has 
been  shown. 

The  primordial  cells,  therefore,  need  no  further  notice  here,  since 
it  is  in  respect  to  their  functions,  and  not  as  mere  histological  ele- 
ments, that  they  are  peculiar.  Besides,  the  manner  in  which  each 
tissue  is  developed  from  its  primordial  cells,  and  the  peculiarities  of 
the  latter  in  each  case,  will  be  explained  in  the  division  of  this  work 
upon  the  "  Tissues  proper." 

Before  proceeding  to  speak  of  the  fluids,  however,  certain  cells 
which  are  either  found  isolated,  or,  at  least,  do  not  coalesce  to  form 
tissues,  will  be  described. 

'  This  discovery  was  announced  in  1839.  Schleiden  had  previously  shown  that 
the  tissues  of  plants  are  formed  from  cells. 


riGMENT-CELLS.  131 


Isolated  Cells:  Cells  not  coalescing  to  form  Tissues. 

Under  the  head  of  isolated  cells,  Carpenter  includes  the  white 
and  the  colored  blood-corpuscles,  epidermis  and  epithelium,  the 
cells  containing  the  spermatozoids  of  the  semen,  and  absorbing  and 
secreting  cells. 

Epidermis  and  epithelium,  however,  perform  their  functions  as  a 
distinct  tissue,  and  will  therefore  be  included  in  the  classification  of 
the  tissues  proper.  Secreting  cells  will  be  described  in  connection 
with  the  various  glands  containing  them ;  and  the  blood-cells  of 
both  kinds,  and  the  spermatophori,  will  be  considered  in  connection 
with  the  fluids  of  which  they  respectively  constitute  a  part. 

The  only  kind  of  cells  to  be  considered  here,  as  being  normally 
scattered  in  the  interstices  of  the  tissues,  and  not  forming  a  tissue 
by  themselves,  is  the  pigment-cell ;  after  which  the  various  forms  of 
cancer-cells  will  be  described,  as  constituting  one  of  the  most  im- 
portant of  the  pathological  developments. 

The  isolated  cells  in  the  nervous  centres  will  be  described  in  the 
chapter  on  "Nerve-tissue." 

I.   PiaMENT-CELLS. 

Pigment-cells  derive  their  peculiarities  from  the  fact  that  the 
granules  they  contain  are  colored,  consisting  of  the  immediate  prin- 
ciple melanine,  described  on  page  103.  As  this  principle  abounds 
in  carbon,  neither  chlorine  nor  strong  acids  remove  the  color  of  the 
granules.  The  latter  are  often  found  lying  among  the  cells,  as  well 
as  within  them.  They  are  also  among  the  minutest  objects  in 
nature,  being  often  less  than  3^ -J- on  of  an  inch  in  diameter. 

It  has  been  shown  that  melanine  is  probably  derived  from  h^ma- 
tine,  and,  like  the  latter,  has  iron  associated  with  it ;  the  pigment  of 
the  choroid  coat  of  the  eye  containing  .254  per  cent,  of  this  metaL 

Distribution  of  Pigment  cells. 
In  the  human  body,  the  distribution  of  pigment-cells  is  quite 
limited.  In  the  eye,  they  are  found  on  the  inner  surface  of  the 
choroid  membrane,  on  the  ciliary  processes  and  the  iris  (uvei),  and 
between  the  choroid  and  the  sclerotica.  They  also  exist  in  the  skin 
of  the  perineum  and  of  the  genital  organs,  especially  of  the  scrotum, 
and  in  the  areola  of  the  mammary  gland.     Pigment-granules  also- 


132  SIMPLE   HISTOLOGICAL   ELEMENTS. 

give  tlie  gray  color  to  the  cells  of  the  cortical  substance  of  the 
cerebrum  and  cerebellum,  and  the  central  part  of  each  half  of  the 
spinal  cord ;  and  pigment-cells  are  also  found  in  the  cervical  pia 
mater  and  the  membranous  labyrinth. 

In  negroes,  the  skin  also  contains  a  layer  of  pigment-cells  over 
the  whole  surface  of  the  body ;  and  to  this  its  blackness  is  due. 
This  is  the  last  formed  and  deepest  layer,  consisting  of  cells  lying 
directly  on  the  basement  membrane  of  the  skin.  Similar  cells, 
darker  than  the  rest,  also  exist  in  this  layer  of  the  skin  of  Eu- 
ropeans, but  their  pigment  is  of  a  lighter  color.  In  fact,  the  differ- 
ence in  amount  and  color  of  pigment 
in  this  layer  of  cells  gives  rise  to  all 
the  varieties  of  color  presented  by  the 
different  races  of  men.  Fig.  68  repre- 
sents the  appearance  of  the  several 
layers  of  cells  in  the  cuticle  of  the 
Section  of  the  cuticle  of  the  negro,    jjegro.     lu  the  outcr  kycrs,  which  are 

a.  Deep  cells,  loaded  with  pigment.    6.  <=  _  . 

Cells  at  a  higher  level,  paler  and  more     flattened     iutO     SCalcS,     the     pigment     is 

flattened,     c    Cells  at  the  surface,  scaly     ^^^^^^y^       2h^QX^.\..       If  the    CUtlclc    of  the 

and  colorless,  as  in  the  white  races.  -J 

negro  be  removed  b}'-  a  blister,  the 
pigment-cells  on  its  inner  surface  will  be  found  clustered  together 
around  circular  spots  of  a  bright  color  where  the  cells  are  wanting. 
The  spots  correspond  to  the  depressions  in  the  under  surface  of  the 
cuticle  into  which  the  papillas  of  the  skin  projected.  On  the  other 
hand,  in  albinoes^  no  pigment-granules  are  found  in  the  epidermis 
at  all. 

Freckles  upon  the  skin  of  the  white  races,  whether  congenital  or 
otherwise,  are  also  due  to  a  development  of  pigment  cells  in  the 
layer  next  underneath  the  epidermis — the  Malpighian  stratum. 

The  pigment  in  the  lungs  of  man  and  the  lower  animals,  both 
under  the  pleura  and  in  the  parenchyma,  is  in  the  form  of  granules; 
but  which  are  not  contained  within  cells.  They  are  probably  mere 
particles  of  carbon.  In  the  lower  animals,  a  single  lobe  is  some- 
times quite  black,  while  the  rest  remains  unchanged ;  though  a 
section  of  it  shows  that  its  function  is  not  essentially,  if  at  all,  im- 
paired by  the  deposit. 

'  So  called  ffjom  nlhus,  white. 


PIGMENT-CELLS. 


133 


Peculiarities  of  Form  of  Pigment-cells. 

Greuerally,  pigment-cells  present  no  peculiarities  of  form;  but 
those  (the  pigmentum  nigrum)  of  the  choroid  membrane  of  the  eye 
are  of  a  hexagonal  form,  resembling  pavement  epithelium.  (Fig. 
69.)     Those  between  the  choroid  and  the  sclerotica  are  somewhat 

Fig.  69.  Fig.  70. 


r?S^^ 


Pigmentum  nigrum  of  adult  human  subject.  A.  Cells 
forming  epithelium  of  the  choroid.  B.  Irregular  cells 
from  substance  of  choroid.  Nuclei  visible  at  a;  pig- 
ment granules,  h. 


Cells  between  the  choroid  and  sclerotic 
of  the  sheep.  {Queckett.) 


fusiform,  and  sometimes  have  bifid  extremities.     Their  appearance, 


as  found  in  the  sheep,  is  shown  by  Fig, 
the  nuclei  are  seen  to  be  white.  In 
albinoes  there  are  no  pigment-granules 
in  the  cells  on  the  choroid,  and  hence 
they  are  not  pigment- qqWs.  Fig.  71 
shows  the  appearance  of  the  cells  of 
the  pigmentum  nigrum,  of  a  black  rab- 
bit at  A,  and  of  the  white  (albino)  rab- 
bit at  B.  In  the  human  foetus,  also, 
the  granules  are  less  numerous  than  in 
the  adult.  The  pigment-cells  of  the 
human  skin  also  often  present  the 
hexagonal  form ;  they  being  here,  in 
fact,  epithelial  (epidermic)  cells. 


70.     In  both  these  fio-ures 


Fig.  71. 


A.  Cells  on  choroid  of  black  rabbit. 
B.  Cells  on  choroid  of  white  rabbit,  des- 
titute of  pigment  granules.    {Queclcett.) 


Distribution  of  Pigment-cells  in  the  Lower  Animals. 

In  the  loiuer  animals^  pigment-cells  present  a  variety  of  forms. 
In  the  skin  of  the  lamprey  they  resemble  the  lacun;\3  and  pores  of 
bone.  (Fig.  72.)  In  the  skin  of  the  frog,  and  some  other  reptiles, 
they  are  of  a  more  stellate  form.  (B^ig.  73.)     In  the  iris  of  the  tiger 


134 


SIMPLE    HISTOLOGICAL    ELEMENTS. 

Fig.  72.  Fig.  73. 


1 

M 

■<  ^^ 

1 

1 

1 

s 

W. 

^^ 

(^ 

i 

1 

(j<,'.\    "^ 

i 

^ 
^ 

p5 

§ 
^ 

y 

^ 

^S:^"^ 

'T\ 

s 

Pigment-cells  of  the  skin  of  the  lamprey.    (Queckett.) 

boa  {Python  tigris),  white  pigment-cells 
are  found.  (Queckett.)  The  red  spots  on 
the  skin  of  the  plaice  are  produced  bj 
minute,  irregular  cells.  Pigment-cells 
are  often  found  in  the  peritoneum  of 
fishes  and  reptiles;  and  the  pigment  se- 
creted in  its  ink-bag,  so  called,  by  the 
cuttle-fish,  is  used  by  artists  under  the 
name  of  "sepia." 


Pigment-cells  in  tail  of  the  tadpole. 
The  transparent  ones  are  the  young 
cells,  in  which  the  pigment  granules 
have  not  yet  appeared. 


Color  of  the  Hair  and  Eyes. 

In  connection  with  the  color  of  the  skin,  that  of  the  hair  and 
eyes  should  be  alluded  to;  though  the  coloring  matter  may  be 
otherwise  than  black  in  case  of  either,  and  therefore  is  not  always 
melanine. 

The  pigment  coloring  the  hair  is  found  generally  both  in  the 
cortical  and  in  the  medullary  portions  of  the  shaft;  and  since  hair 
is  an  epithelial  appendage,  as  will  be  shown,  we  might  expect  that 
its  color  will  correspond,  within  certain  limits,  with  that  of  the  skin. 
Spots  of  black  hair  are  found  (as  in  the  hog)  to  grow  on  patches  of 
skin  of  the  same  color.  In  the  albino,  on  the  other  hand,  the  hair 
is  colorless.  For  the  particulars,  however,  consult  the  section  on 
"The  Hair." 

The  color  of  the  eye  is  determined  by  that  of  the  iris,  as  is  ex- 
plained in  the  last  chapter  of  this  work.  It  is  blue,  hazel,  and,  in 
some  cases,  nearly  jet  black.  The  conformity  of  color  with  that  of 
the  skin  (or  the  complexion)  is  not  so  rigid  as  is  that  of  the  hair; 
and  yet  the  disparity  ranges  within  certain  limits.  The  irides  of 
albinocs  are  of  a  pink  color;  since,  not  being  covered  with  pigment- 
cells,  the  numerous  very  minute  bloodvessels  of  the  iris  are  visible. 


PIGMENT-CELLS. 


135 


Section  of  skia  of  the  noee,  showing 
pigment.  (Queclcett.) 


The  sebaceous  follicles  of  the  skin  being  I'^ig-  74. 

in  close  relation  with  the  hair-bulbs,  are 
sometimes  found  distended  with  pigment. 
This  is  especially  the  case  in  acne,  a  dis- 
ease essentially  consisting  of  an  enlarge- 
ment and  suppuration  of  the  sebaceous 
follicles,  and  in  which  masses  of  black 
matter  may  be  pressed  from  them.  Fig. 
74  shows  a  section  of  the  skin  of  the 
nose  having  a  stratum  of  black  pigment 
in  the  deepest  portion  of  the  cuticle, 
which  also  dips  down  into  the  sebaceous 
follicles,  seen  on  each  side  of  the  two  hairs  growing  from  the  corium. 

development  of  Pigment-cells. 

The  stimulus  of  solar  light  doubtless  exerts  an  influence  on  the 
development  of  the  pigment-granules.  In  many  persons  a  strong 
sunlight  produces  freckles ;  and  exposure  for  several  years  to  a 
tropical  climate  renders  the  fairest  complexion  sallow.  The  Dutch 
who  have  for  several  generations  resided  in  Africa,  have  at  length 
become  so  black  as  to  be  distinguished  from  the  natives  by  their 
features  only,  and  not  by  their  color.  The  natives  of  the  torrid 
zone  almost  invariably  have  black  hair  and  eyes.  The  infant 
negro  is  scarcely  darker  than  the  white  during  the  first  few  days 
after  birth.^  The  genital  organs  become  colored  on  the  third  day, 
and  the  whole  body  on  the  fifth  and  sixth. 

The  stimulus  of  solar  light  is  essential  to  the  development  of  the 
green  pigment  (chlorophyl)  of  plants,  which  also  consists,  in  great 
part,  of  carbon ;  and  with  this  fact  the  preceding  may  be  naturally 
associated. 


Functions  of  Pigm^ent-cells. 
The  pigment-cells  in  the  pigmentum  nigrum  of  the  eye  are  im- 
portant principally  in  the  way  of  interrupting  or  absorbing  light, 
and  thus  contributing  to  the  perfection  of  vision.  Hence  albinoes 
cannot  see  well  in  the  full  light  of  a  sunny  day.  In  the  substance 
and  on  the  posterior  surface  of  the  iris,  however,  the  pigment-cells 

'  Some  writers  maintain  that  the  different  varieties  of  the  human  race  are  due 
to  climatic  influences,  exerted  through  a  long  succession  of  generations.  If  color 
alone  were  to  be  taken  into  the  account,  this  idea  would  be  more  plausible. 


136  SIMPLE    HISTOLOGICAL   ELEMENTS. 

seem  to  be  intended,  at  the  same  time,  for  ornament  also — giving 
the  peculiar  color  to  the  eye.  The  variously  colored  cells  on  the 
surface  of  the  lower  animals  apparently  subserve  the  latter  object 
alone.  We  cannot,  however,  remark  the  same  in  regard  to  the 
colored  spots  on  the  peritoneum  of  some  of  them. 

The  presence  of  pigment-cells  in  the  epithelium  of  the  skin  of 
man  bears  some  relation  to  the  degree  of  solar  light  and  heat  to 
which  it  is  exposed;  but  which  is  not  well  understood. 

Pigment-cells  abound,  as  has  been  stated,  in  the  human  brain  and 
spinal  cord.  That  the  function  of  these  organs,  or  of  even  the  cells, 
does  not  depend  on  the  color  of  the  contained  granules,  may  be 
inferred  from  the  fact  that  in  the  spinal  cord  of  the  frog  the  cells 
contain  colorless,  instead  of  colored,  granules. 

The  fact  that  the  pigment-granules  in  the  epidermic  cells  of  the 
areolae  around  the  mammilla  of  the  human  female  are  increased  in 
pregnancy,  is  well  known,  and  its  darker  color  is  regarded  as  one 
of  the  signs  of  that  condition.  We  can  only  associate  this  fact 
with  the  development  of  the  whole  mammary  gland  at  the  same 
time,  in  consequence  of  the  sympathy  existing  between  it  and  the 
uterus.  It  may  also  be  added  that  an  increased  tendency  to  develop 
pigment-granules  is  often  manifested  in  other  parts  of  the  body 
during  the  last  weeks  of  pregnancy,  in  the  form  of  freckles,  espe- 
cially of  the  face,  neck,  and  upper  part  of  the  chest. 

Regeneration  of  Pigment-cells. 
In  the  case  of  a  young  man  who  had  a  congenital  black  spot  on 
the  skin  just  below  the  angle  of  the  mouth,  a  blister  was  applied  to 
remove  the  epidermis,  and  then  the  nitrate  of  silver  till  the  corium 
was  completely  abraded.  Still,  the  pigment-cells  were  reproduced 
as  abundantly  as  before.  In  case  of  ephelis  hepatica  affecting  the 
forehead,  cheek,  or  back  of  the  neck,  the  same  experiment  has  been 
followed  by  the  same  result.  After  such  failure,  however,  the  pig- 
ment has  sometimes  spontaneously  disappeared.  In  negroes,  if  a 
portion  of  the  skin  be  lost,  that  which  replaces  it,  for  a  long  time,  is 
deficient  in  pigment-cells.  In  some  cases,  however,  the  new  skin, 
after  many  years,  becomes  as  black  as  the  original  integument. 

Pathological  Formation  of  Pigment-cells. 

The  abnormal  development  of  pigment-cells  or  granules  in  the 
tissues  constitutes  melanosis.    The  latter  is  not,  therefore,  itself  ma- 


CANCER-CELLS. 


137 


lignant,  but  it  often  forms  a  part  of  cancerous  and  other  malignant 
growths.  Pigment-cells  developed  on  patches  of  skin  (most  fre- 
quently of  the  forehead  or  other  part  of  the  face)  constitute  the 
disease  called  ephelis  hepatica;  it  being  usually  associated  with 
disease,  often  merely  functional,  of  the  liver.  A  different  form  of 
deposit  of  pigment  on  the  skin  is  also  mentioned  by  Queckett,  in 
which  it  could  be  brushed  off  from  the  surface  with  a  camel's-hair 
pencil.  It  is  believed  that  the  face  only  is  liable  to  this  form  of 
deposit;  and  its  actual  existence  is  to  be  distinguished  from  some 
other  pigment  purposely  applied  by  the  patient  (usually  a  female) 
to  deceive  the  medical  attendant. 

Moles  and  freckles,  when  congenital,  are  due  to  a  deposit  of  pig- 
ment-cells, from  a  cause  not  understood. 

The  deposit  of  pigment  sometimes  occurring  in  cases  of  acne  has 
already  been  mentioned. 


II.   Cancer-cells. 

Cancerous  masses  consist  of  the  four  following  elements,  in  addi- 
tion to  bloodvessels : — 

1.  A  matrix  of  homogeneous  substance,  either  hyaline  or  gran- 
ular. 

2.  Fibres  more  or  less  approaching  those  of  white  fibrous  tissue 
in  appearance. 

3.  A  great  variety  of  cells  and  nuclei,  some  of  which  are  gene- 
rally regarded  as  peculiar  to  cancer. 

4.  A  peculiar  cream-like  fluid,  termed  the  "cancer-juice." 
These  elements  vary  extremely  in  their  proportion  in  the  different 

forms  of  cancer,  of  which  three  are 

usually  designated : —  ^^'  ' 


"whi 

the  fibres,  one  or  both,  predominate, 

(Fig.  75.) 

2.  Encephaloid,  or  cellular  cancer, 
being  constituted  mainly  of  cells. 
(Fig.  76.) 

3.  Colloid  cancer,  in  which  there 
is  a  predominance  of  a  peculiar  ge- 
latinous fluid. 

These  three  forms  are  often  found 
coexisting  in  the  same  cancerous 
mass.  Melanotic  cancer  is  distin- 
guished merely  from  having  pig- 
ment-cells added  to  the  cancer  ele- 
ments. (Fig.  77.) 

Neither  the  homoo-eneous  matrix 


Caucer-ccUs  iu  ii  librous  stroma. 


138 


SIMPLE    HISTOLOGICAL   ELEMENTS. 


nor  the  fibres  can  be  regarded  as  peculiar  to  cancer.    Only  the  cells 
and  the  cancer-fluid  are  so.     But,  in  encephaloid  cancer,  the  fluid  is 


Fig.  76. 


Fig.  77. 


Encephaloid.     Simple  and  compound  cancer-cells. 


Melanotic  cancer.  {Bennett.) 


not  always  found.  The  cells  alone  will  be  here  described ;  and  the 
investigations  of  Dr.  F.  Donaldson,  of  Baltimore,  will  be  quoted,  as 
the  most  explicit  account  hitherto  given  of  their  various  forms.* 

With  a  power  of  555  diameters.  Dr.  D.  found  that  the  cells,  the 
nuclei,  and  the  nucleoli  existing  in  cancer  are  all  peculiar  to  it. 

A.  The  cancer-nuclei  (Fig.  78),  whether  inclosed  in  a  cell  or  free, 
are,  in  their  form  and  appearance,  the  most  constant  and  unva- 
rying of  all  the  cancer  ele- 
ments. They  are  generally 
round  or  ovoid  in  shape, 
with  a  length  of  from  ^s^jso 
to  jg'g^  of  an  inch.  Their 
contour  is  dark  and  well 
defined,  the  interior  con- 
taining minute  granules. 
In  width  they  measure 
from  3  3'^,  5  to  55'j5(j  of  an 
inch.  It  is  noticeable  that 
while  in  other  cells  the 
nucleus  is  generally  found 
near  the  centre,  in  cancer 
no  rule  in  this  respect  is 
observed.  Two  or  more 
nuclei,  with  their  nucleoli, 
both  of  great  size  in  pro- 
portion to  the  diameter  of 


Cancer  nuclei,  a.  Type  form.  b.  The  .«ame,  witli  a  piece 
nicked  out  of  the  side  accidentally,  e.  Shows  a  free  nu- 
cleus in  which  the  molecular  granules  are  very  minute, 
often  met  with  in  perfectly  fresh  specimens,  d.  A  nucleus 
in  which  larger  granules  have  commenced  to  form.  e.  The 
characteristic  nucleolus,  with  its  dark  contour  and  bright 
centre,  h.  Fine  molecular  granules,  i.  Tlio  second  va- 
riety of  granules,  or  gray  granulations.    J.  Fat-granules. 


American  Journal  of  the  Medical  Sciences,  vol.  xxv.  p.  43. 


CANCER-CELLS. 


139 


the  cell,  are  often  seen  in  all  the  varieties  of  cancer-cells ;  while 
other  cells,  as  the  epithelial,  rarely  have  more  than  one. 

B.  The  nucleoli  are  of  a  yellowish  tinge  and  peculiar  brightness, 
and  average  Yaii^u  of  an  inch  in  diameter.  Sometimes  two  or  three 
are  found  in  the  same  cell.  For  the  perfect  exhibition  of  these  cha- 
racteristics of  cancer-nucleoli,  it  is  necessary  that  the  specimen  be 
fresh. 

M.  Eobin  notices  the  action  of  acetic  acid  upon  cancer-nuclei  and 
their  nucleoli  as  peculiar,  since  it  renders  the  nucleus  and  cell  gra- 
dually paler,  though  destroying  neither,  while  the  nucleolus  is  en- 
tirely unaffected  by  it  (p.  116). 

c.  Cells. — Cancer-cells  present  a  considerable  diversity  of  form. 
Dr.  Donaldson  mentions  the  following  varieties: — 

1.  The  polygonal  or  more  or  less  spherical  and  ovoid  cell. 

2.  The  caudated  cell. 
8.  The  fusiform  cell. 

4.  The  concentric  cell. 

5.  The  compound  or  mother  cell. 

6.  Agglomerated  nuclei  connected  by  granular  homogeneous 

substance. 

1.  The  polygonal  cell  (Fig.  79)  may  be  regarded  as  the  type  in 
cancer.  Thus,  in  hard  tumors  the  cells  are  found  irregular,  and 
sometimes  almost  triangular  in  form.  In  medullary  (encephaloid) 
cancer,  cells  of  an  ovoid  or  spherical  shape  are  oftenest  met  with. 

Fig.  79. 


Polygonal  cancer-cells,  g.  Spherical  cells,  a.  Dark  contour  of  inclosed  nucleus,  e.  The  nucle- 
olus, k.  A  nucleus  with  its  contour  pressed  out  of  shape.  I.  A  form  of  cell  frequently  seen,  where 
there  is  a  deficiency  of  part  of  the  wall.    /.  From  pressure  rendered  triangular. 


140 


SIMPLE    HISTOLOGICAL    ELEMENTS. 


Perfectly  round  cells  are  rarely  seen ;  though  cells  approaching  this 
form,  of  variable  diameter,  are  often  discovered. 

2.   Caudated  Cells. — This  form  is  invariably  found  in  the  bladder 
and  was  formerly  considered  the  cancer-cell.   It  is  of  irregular  form 


Fig.  80. 


ludated  cancer-cclls.    m.  The  most  usual  forms,     n.  Cells  containing  double  nuclei.   Cancer  of  the 
bladder  invariably  contains  this  variety. 


Fig.  81. 


having  from  two  to  five  prolongations  or  poles'branching  off  from 

the  body  of  the  cell.  (Fig.  80.) 

3.  Fusiform  Cancer-cell  (Fig.  81). 
— This  shape  is  caused  by  a  swelling 
in  the  centre,  the  ends  being  point- 
ed so  as  to  form  an  acute  angle.  M. 
Robin  has  invariahhj  found  it  when- 
ever cancer  has  attacked  the  bones. 
These  cells  somewhat  resemble  the 
fusiform  fibres  of  fibro-plastic  tissue^ 
(Fig.  82),  but  may  be  distinguished 
from  them  by  their  greater  width 
and  length,  the  presence  of  the  clear, 
bright  centre,  and  the  greater  size 
of  the  nuclei. 

Fusiform  cancer-cells,  a.  The  nucleus,  wtich  In 
tills  variety  of  cell  is  almost  constantly  ovoid.  The 
transverse  diameter  of  the  cell,  and  the  size  of  the 
nucleus  in  proportion  to  the  coll,  together  with  the 
characteristic  nucleolus,  distinguish  this  variety  from 
the  fusiform  fibro-plastic  element. 


And  have  been  mistaken  for  them  hy  some  oh.servers. 


CANCEK-CELLS. 


141 


Fig.  82. 


Fig.  83. 


rusiform  fibres  of  fibro-plastic  tissue.  4.  The  narrow 
and  long  fusiform  cell,  containing  a  nucleus  (.5)  with  a 
small  dot  in  its  centre  for  a  nucleolus.  Average  length 
of  cell,  l-300th  of  an  inch. 


Two  concentric  cancer-cells,  a.  The 
cancer-nucleus,  the  size  of  which  is  al- 
ways in  proportion  to  the  innermost  cir- 
cle,    e.  The  brilliant  nucleolus. 


4 
body, 


The  concentric  cancer-cell  is  formed  of  an  ovoid  or  spherical 
surrounded  by  concentric  rings,  increasing  in  size  as  they  go 

further  out.     This  variety 


Fig.  84. 


never  forms  the  basis  of  a 
cancerous  tumor,  and  is 
met  with  but  rarely.  (Fig. 
88.) 

5.  The  compound  or  mo- 
ther cells  of  cancer  have  re- 
ceived this  name  from  the 
idea  entertained  by  some 

Fig.  85. 


Compound  cancer-cells,  a.  Nucleus  :  when  there  are  more 
than  one  nucleus  within  a  cell,  they  are  smaller  than  the  sin- 
gle nucleus,    o.  From  Lebert. 


Agglomerated  cancer-nuclei,  a 
Nucleus,  p.  Granular  homogene- 
ous matrix. 


authors,  of  their  splitting  up  into  smaller  segments,  and  multiplying 
by  division.  They  are  of  variable  form,  and  often  contain  three, 
four,  or  more  cancer-nuclei.  (B^igs.  84  and  64.) 

6.  Agglomerated  nuclei  are  also  rarely  met  with,  which  seem  to  be 
held  together  by  the  granular  homogeneous  substance  in  which 
they  are  generated.  They  seem  to  have  no  cell-wall  about  them, 
and  may  be  recognized  by  the  bulk  of  their  envelop.  (Fig.  "60) 


142 


SIMPLE    HISTOLOGICAL    ELEMENTS. 


as 


4  5  0 


to 


# 


>^ 


Spherical  fibro-plastic  cells.  6.  Well- 
marked  cell.  7  and  8.  Nuclei  inclosed 
in  cells  or  floating  free  ;  tran.sverse  dia- 
meter, l-,W00fh  inch. 


Fig.  87. 


Elements  liable  to  be  mistalcenfor  Cancer-cells. 

It  is  important,  in  this  connection,  to  specify  the  histological  ele- 
ments which  may  be  mistaken  by  the  microscopist  for  the  cancer- 
cells  just  described;  though,  with  the  exception  of  the  first  two,  the 
distinction  is  easily  made  at  a  glance. 

1.  H\\Q  fusiform  corpuscles  of  fibro-j)lastic  tissue^  are  often  as  much 
of  an  inch  long.  Their  comparative  narrowness,  the 
smallness  of  their  nuclei,  the  nucleolus, 
and,  indeed,  their  whole  aspect,  distin- 
guish them  from  cancer-cells.  They 
have  already  been  shown  by  Fig.  82. 

2.  The  fibro-plastic  cells  and  their  free 
nuclei  (Fig.  86)  may  be  mistaken  for 
cancer-cells  by  a  superficial  observer. 
These  cells  are  ovoid,  sometimes  poly- 
gonal, and  vary  from  gg'^u  ^o  tsju  of 
an  inch  in  diameter.  The  nucleus  and 
nucleolus,  however,  appear  different 
from  those  of  cancer,  and  the  granules 
they  contain  are  very  much  finer  and 
of  more  uniform  size.  The  free  nuclei 
are  so  much  smaller  as  to  be  at  once 
recognized. 

Both  of  the  fibro-plastic  elements  just 
mentioned  are  found  in  the  brain,  blad- 
der, ovaries,  mammary  gland,  uterus,  &c., 
and  in  the  healthy  state  as  well  as  in 
inflammatory  products.  These  will  also 
be  found  ivith  cancer-cells,  if  inflam- 
mation has  existed  in  a  cancerous  de- 
posit. 

3.  Mr.  Bennett  thinks  that  the  cells 
escaping  from  the  cavities  of  enchondro- 
maious  tumors,  while  they  are  softening, 
may  be  mistaken  for  cancer-cells.  Dr. 
Donaldson  does  not  accept  this  as  pro- 
bable. 

4.  Nor  can  pus-corpuscles  be  mis- 
taken for  cancer-cells,  though  often 
found  mixed  with  the  latter. 

5.  The  appearance  of  tubercle-corpus- 
cles^ as  contrasted  with  cancer-cells,  is 

shown  in  Fig.  87.     The  former  were,  however,  magnified  833  times, 
the  cancer-cells  but  555  times. 

6.  The  contrast  between  epithelial  cells  in  different  stages  of  de- 

'  This  is  a  phrase  applied  to  the  fibres,  cell?,  &c.,  developed  in  exuded  plasma, 
generally  in  case  of  inflammation. 


,./ 


Tubercle-corpuscles  (nuclei)  distin- 
ijttishedfrom  cancer.  1.  Corpuscle.s  found 
la  softened  tuliercular  matter  ;  small, 
irregularly  forniod,  globular  bodies  with 
many  nucleoli.  2.  Nucleoli  and  inte- 
rior granules.     .3.  Free,  loose  granules. 


CAXCER-CELLS, 


143 


velopment,  and  of  the  various  kinds,  and  cancer-cells,  is  seen  in  the 
four  next  figures  (Figs.  88  to  91). 


Fig.  88. 


Fig.  89. 


Young  epithelial  cells  filled  with  few  and 
small  gnmules.  w.  Cell-wall.  x.  The  nu- 
cleus, very  small  in  proportion  to  cell,  and 
containing  no  nucleolus.   (Lebert.) 


Cells  from  the  epidermis,  y.  Nucleus  without  nucle- 
olus, diminutive  in  proportion  to  cell.  i.  The  cell,  with 
homogeneous  minute  granulations  filling  up  the  cen- 
tre. Diameter  of  the  cell,  when  taken  from  the  skin, 
l-250th  inch. 

Fig.  91. 


Buccal  epithelial  scales.  11.  Irregularly  poly- 
gonal contour.  12.  The  characteristic  nucleus 
without  any  appearance  of  a  nucleolus ;  which  is 
rarely  met  with  in  epidermic  cells,  or  in  those  com- 
ing from  the  buccal  surface. 


Ciliated  epith^um  from  air-passages.  9. 
Hair-like  appendages  (cilia),  which,  during 
life,  are  constantly  in  motion.  10.  Nucleus  clear 
in  the  centre. 


Since  crystals  of  cholesterine,  of  ammonio-magnesian  phosphate, 
and  of  margarine,  fat-globules,  filaments,  and  pus,  may  be  found 
mixed  with  cancer-cells,  Dr.  Donaldson  insists  upon  the  examination 
of  every  part  of  a  mass  supposed  to  be  cancerous,  before  deciding 
that  it  is  not  so.  "If  but  one  cancer-cell  be  found,  it  is  conclusive," 
says  Dr.  Donaldson;  a  proposition,  however,  which  should  not  be 
practically  adopted,  as  will  appear. 

"Out  of  the  body,  cancer  elements  change  more  rapidly  than  any 
others;  nor  can  they  be  preserved  in  any  fluid;"  therefore  they 
should  be  examined  at  once.  Within  the  first  day  they  may  become 
degenerated  by  the  appearance  of  fatty  granules,  which  often  hide 
their  distinctive  characteristics. 

Epithelial  cancer  will  be  spoken  of  in  connection  with  "  Epithe- 
lium." 


Much  discussion  has  arisen,  of  late,  in  regard  to  the  value  of  the 
microscope  in  the  diagnosis  of  cancer ;  one  party  contending  that 
this  instrument  is  totally  unreliable  in  this  respect,  while  the  oppo- 


144  SIMPLE   HISTOLOGICAL    ELEMENTS. 

site  would  rely  upon  it  alone.     The  following  is  believed  to  be  the 
only  tenable  view  of  this  subject : — 

1.  In  all  cases  of  ic ell- developed  cancerous  formation,  the  micro- 
scope, in  the  hands  of  one  skilled  in  its  use,  will  alone  demonstrate 
the  true  character  of  the  growth,  unaided  by  any  knowledge  of  its 
appearance  to  the  naked  eye,  of  its  tactile  properties,  or  of  the  his- 
tory of  the  case.  This  it  will  do  by  detecting  one  or  more  of  the 
peculiar  forms  of  cell  or  nucleus  already  described.  Here,  therefore, 
the  diagnosis  may  be  positively  expressed  in  the  affirmative. 

2.  But  there  are  all  possible  grades  of  development,  from  the  en- 
cephaloid,  as  the  most  strongly  pronounced  form  of  cancer,  to  the 
fibrous  cancer,  and  onward  to  the  simple,  innocent  sarcoma.  There 
will,  therefore,  be  a  corresponding  shading-oft"  of  the  peculiarities 
of  the  minute  cancer  elements  (cells,  nuclei,  &c.)  into  the  normal 
elements  of  the  tissues.  Besides,  when  cancer-cells  are  still  young, 
they  do  not  present  the  peculiarities  before  mentioned.' 

In  the  imperfect  or  early  development  of  cancer,  therefore,  the 
cancer-cell  may  so  nearly  resemble  the  fibro-plastic  or  some  other 
cell,  that  a  microscopic  discrimination  is  impossible.  Here,  then, 
the  microscopic  diagnosis  must  be  guarded,  and  the  history  of  the 
case  and  the  other  sensible  properties  of  the  growth  must  decide. 

3.  The  cancer  elements  may  exist  in  small  amount  in  a  mass  sup- 
posed to  be  cancerous,  and  in  the  midst  of  a  variety  of  other  minute 
elements,  and  therefore  escape  detection.  If  so,  the  microscopic 
diagnosis  is  inferentially  negative,  but  not  unqualifiedly  so.  The 
unaided  eye,  the  sense  of  touch,  and  the  history  of  the  case  may, 
however,  together,  decide  the  diagnosis  unqualifiedly,  either  in  the 
affirmative  or  the  negative. 

4.  In  cases  of  well-developed  cancer,  therefore,  the  microscope, 
since  it  alone  may  decide  the  diagnosis,  is  in  the  highest  degree 
reliable.  In  the  other  two  cases  mentioned,  it  is  less  reliable  than 
the  other  means  alluded  to;  but  here,  also,  it  may  prove  of  the 
highest  value,  by  confirming  or  opposing  the  diagnosis  suggested 
by  tbem.  It  is  the  absurd  assumption  that  the  microscope  can  de- 
cide in  every  possible  case,  which  has  brought  the  instrument  into 
disrepute.  It  merely  enables  us  to  see  what  would  be  invisible 
without  it;  and  gives,  so  far  as  the  minute  elements  are  concerned, 
an  advantage  over  those  who  refuse  to  use  it,  like  that  which  one 
who  has  perfect  sight  enjoys  in  respect  to  things  visible  to  the 
naked  eye,  as  compared  with  the  purblind.  But  as  the  unaided 
sight  alone  is  almost  never  expected  to  decide,  in  case  of  suspected 
cancer,  without  regard  to  the  tactile  properties  and  the  history  of  the 
case;  so  the  sight,  when  aided  by  the  microscope — for  it  is  mere 
sight  still — must  not,  except  in  a  single  class  of  cases,  be  relied 
upon  alone.  In  these  it  should  be  recognized  as  an  arbiter  in  the 
diagnosis  of  cancer;  in  all  other  cases  it  is  merely  a  valuable  aid. 

'  All  pulhoh)(ji((tl  narlij-f armed  cdh  have  no  ospccial  character  peculiar  to  thcni. 
(  Wedl,  p.  60.) 


SECOND  DIVISION. 

THE  FLUIDS  OF  THE  HUMAN  BODY  (HYGROLOGYO- 

In  their  histological  relations,  the  fluids  may  be  considered  under 
the  four  following  chapters : — 

I.  The  blood,  including  lymph  and  chyle. 
II.  Serous  secreiions  and  transudations  (effusions),  and  exudations. 

III,  Mucous  and  glandular  secretions. 

IV.  The  cutaneous  secretions. 

There  is,  however,  one  histological  element  which  is  common  to 
no  less  than  six  of  the  fluids  about  to  be  considered,  and  this  will 
be  described  before  entering  upon  the  fluids  individually.  This 
element  is  the  "cytoid  corpuscle"*  {Senle),  and  which  has  been 
variously  termed  the  lymph-corpuscle,  the  chyle-corpuscle,  the  co- 
lorless blood-corpuscle,  the  mucus,  the  pus,  and  the  exudation-cor- 
puscle, accordingly  as  it  has  been  found  in  these  six  fluids  respect- 
ively. 

Cytoid  corpuscles  (Fig.  92)  have  a  granular  investing  membrane 
or  cell- wall,  and  contain  either  a  single  round  and  occasionally  oval 
or  reniform  nucleus,  or  several  nuclei  heaped  one 
upon  another.      They  are  not  perfectly  spherical.         ^^^'  ^^' 
Their  diameter  varies  with  the  specific  gravity  of  the         *^ 
fluid  containing  them,  since  they  are  highly  endos-         •      3 
motic.     Hence  they  are  larger  in  saliva  than  in  pus.       (©)  ^ 
The  addition  of  water  to  any  fluid  containing  them, 

■1  .  .  Cytoid  corpuscles 

causes  them  to  enlarge,  and  their  mvestmg  mem-   of  tiood.  1.  :fatu- 
brane  to  appear  less  folded  and  smoother.     Their  r^i  ^.ppearanee    2 

^^  _  and  3.  Changed  by 

diameter  varies,  therefore,  even  in  the  same  fluid,   dilute  acetic  acid. ' 

'  From  'vypk,  wet,  fluid,  and  Xoyog.  The  term  Phlegmatology  has  also  been  used  : 
but  its  derivation  being  founded  on  the  obsolete  notions  of  the  ancients  respecting 
phlegm,  it  should  be  discarded. 

^  /.  e.  cell-resembling  corpuscle,  from  xvro;,  cell,  and  iT^of,  resemblance. 

10 


146 


THE   FLUIDS. 


witli  variations  in  its  composition.  It  usually  ranges  between  ^^^-^ 
and  o^'oo  of  an  inch  in  the  six  fluids  before  named.  Bowman  re- 
marks that  these  corpuscles  are  usually  smaller  in  mucus  than  in 
pus,  and  that  they  are  also  less  distinctly  granular;  and  Hassall 
asserts  that  they  are  smaller  in  chyle  than  in  lymph.  In  the  blood 
they  are  specifically  lighter  than  the  colored  corpuscles,  since  they 
both  contain  more  fat,  and  are  also  deficient  in  the  ferruginous 
haematine. 

Cytoid  corpuscles  are  ^Iso  easily  acted  upon  by  extremely  dilute 
mineral  acids,  or  moderately  dilute  solutions  of  organic  acids  (uric, 
lactic,  &c.);  all  of  which  render  the  nuclear  matter  more  perceptible. 
And  since  pus  easily  passes  into  the  acid  fermentation,  on  exposure 
to  the  air,  its  previously  invisible  nuclei  are  at  once  thus  rendered 
apparent.    Hence  the  "pus-corpuscle,"  so  called,  when  observed,  has 

been  generally  found  to  be  more  gran- 
ular than  the  "  mucus-corpuscle ;"  and 
the  original  simple  nucleus  is  seen  to 
have  divided  into  two,  three,  or  more 
vesicles,  in  which  one  or  two  granules 
may  be  distinguished.  (Fig.  93.) 

But  the  peculiar  modifications  un- 
dergone by  the  cytoid  corpuscle',  in  the 
fluids  just  mentioned,  will  be  more 
particularly  adverted  to  in  connection 
with  each  in  detail. 


Fig.  93. 


Ptts-corpuscles  changed  by  acetic  acid. 
«.  Tlie  irregular  contour  of  the  corpuscle 
Ireed  from  the  granules,  leaving  the 
nuclei  clear,  t.  Characteristic  nucleus 
without  any  nucleolus,  u.  Free  nuclei, 
the  walls  having  been  destroyed,  v. 
Remnant  of  contour. 


Development  of  Cytoid  Corpuscles. 
The  lymph,  chyle,  and  colorless 
blood-corpuscles  are  uniformly  regard- 
ed as  instances  of  free  cell-develop- 
ment (p.  120).  It  is  probable  that  the 
cytoid  corpuscle  is  always  so ;  in  pus, 
mucus,  and  exudations,  as  well  as  in  the  three  fluids  just  mentioned. 
It  appears  to  be  a  general  law  that  cytoid  corpuscles  are  developed 
in  any  fluid  approximating  nearly  in  composition  to  the  blood- 
plasma,  since  such  a  fluid  contains  their  nutritive  elements.  The 
latter,  of  course,  exist  in  exudations;  and  the  relations  to  these  oi' 
pus,  which  will  be  pointed  out  in  the  following  chapter,  demonstrate 
their  presence  in  pus  also.  In  mucus,  the  cytoid  corpuscles  are  also 


LYMPH.  147 

probably  developed  in  the  liquor  muci,  the  latter  containing  their 
nutritive  elements;  and  are  not  secreted  by  the  epithelial  cells  of  the 
mucous  membrane,  as  is  often  asserted.  The  idea  of  Gluge,  that 
pus-corpuscles  are  merely  free  nuclei,  can  be  adopted  only  by  such 
as  still  maintain  that  there  is  a  wide  distinction  between  them  and 
the  mucus-corpuscle  (p.  116). 

Functions  of  Gytoid  Corpuscles. 

The  colorless  corpuscles  of  the  blood  are,  with  very  valid  reasons, 
regarded,  by  T.  "Wharton  Jones,  as  the  parent  cells  of  the  red  cor- 
puscles ;  and  those  of  lym.ph  and  chyle  are  formed  in  these  fluids 
preliminarily  to  entering  the  blood.  In  the  lymphatics  of  the 
spleen,  and  in  the  thoracic  duct,  however,  the  cytoid  corpuscles 
appear  already  to  have  developed  red  blood-corpuscles,  and  which 
enter  the  blood  with  the  lymph  and  chyle. 

In  exudations,  the  cytoid  corpuscles  constitute  the  basis  of  new 
tissue,  as  is  generally  understood;  while  in  mucus  and  pus  they 
appear  to  be  developed  in  accordance  with  the  law  announced 
above,  but  do  not  advance  to  any  higher  degree  of  organization. 


CHAPTER   I. 


THE   HISTOLOGICAL   RELATIONS   OF  THE  BLOOD,  INCLUDING 
LYMPH  AND   CHYLE. 

Since  lymph  and  chyle  are,  in  a  physiological  point  of  view,  to 
be  regarded  as  blood  in  its  primary  stages  of  development,  some 
remarks  on  these  fluids  may  appropriately  precede  the  description 
of  the  blood  itself. 

I.  Lymph. 

Lymph,  as  obtained  from  the  lymphatic  vessels,  is  a  colorless  or 
slightly  yellowish  and  somewhat  opalescent  fluid,  of  a  saltish,  insi- 
pid taste,  with  an  alkaline  reaction.  It  coagulates  in  from  four  to 
twenty  minutes  after  being  exposed  to  the  air,  forming  a  gelatinous, 
colorless  coagulum. 


148  THE   FLUIDS. 

Seen  under  the  microscope,  lymph  consists  of  two  portions :  1. 
The  fluid  portion,  or  liquor  lymphce,;  2.  Certain  morphological  ele- 
ments. 

1.  The  liquor  lymphcB  is  similar  in  chemical  composition  to  the 
liquor  sanguinis,  as  might  be  expected ;  there  being,  however,  more 
water,  with  less  albumen  and  fibrine.  The  saline  and  extractive 
matters  are,  however,  proportionably  more  abundant.  It  is,  in  fact, 
a  dilute  liquor  sanguinis.  The  albumen  varies  from  4.34  {Mar- 
chawl)  to  60.02  {L' Rentier)  in  1,000  parts,  and  the  fibrine  from  .32 
to  .52.  Fat  constitutes  .264,  and  water  924.36  to  969.26  parts.  Of 
the  liquor  sanguinis  about  903  parts  in  1,000  are  water.  Contrary 
to  what  has  been  asserted,  the  albumen  and  fibrine  of  the  lymph 
appear  to  be  identical  with  those  of  the  blood. 

2.  The  histological  elements  of  lymph  are — 1.  Cytoid  corpuscles 
(lymph-corpuscles) ;  2.  Fat-drops ;  and  3.  Nucleus-like  formations. 

1.  The  cytoid  corpuscles  have  already  been  described  (p.  145). 
They  average  about  og^oti  of  an  inch  {s-q^o  to  ssVo)  i°  diameter  in 
this  fluid  (2 52 5)  Sassall). 

2.  The  fat-globules  present  nothing  peculiar.  (See  p.  73.) 

3.  The  nucleus-like  bodies  are  probably  the  still  undeveloped 
cytoid  corpuscles. 

It  should  also  be  added  that  in  the  lymph  obtained  from  the 
lymphatics  of  the  spleen,  red  corpuscles,  identical  with  those  of  the 
blood,  are  found.  They  have  also  been  found  in  the  lymph  of 
starving  animals.  The  explanation  of  this  fact  has  already  been 
given  (p.  147),  though  it  has  also  been  suggested  that  they  are  ob- 
tained from  bloodvessels  opened  in  the  search  for  them. 

Origin. — Lymph  is  derived  mainly  from  the  overplus  of  the 
plasma  exuded  from  the  capillaries,  into  the  parenchyma  of  organs 
for  their  nutrition,  or  for  the  formation  of  secretions.  It,  more- 
over, contains  some  of  the  immediate  principles  resulting  from  the 
dis-assimilation  of  the  tissues. 

It  is  impossible  to  calculate,  with  any  approximation  to  accuracy, 
the  quantity  of  lymph  in  the  human  body.  Bidder  believes  that 
about  28.6  pounds  pass  from  the  thoracic  duct  into  the  subclavian 
vein  in  twenty-four  hours — Q.Q  pounds  being  true  chyle,  and  22 
pounds  being  lymph.  Few  will  object  to  the  last  estimate  as  not 
being  sufficiently  high. 

Uses. — Lymph,  though  derived  from  the  blood,  is  to  enter  it  a 
second  time.    It  is,  therefore,  to  be  regarded  as  blood  in  its  primary 


CHYLE.  149 

stage  of  formation.     As  it  traverses  the  lymphatic  glands,  and  is 

elaborated  by  them,  it  approximates  more  and  more  nearly  to  the 
blood  itself,  till  it  is  at  last  mingled  with  the  latter  from  the  thoracic 
and  the  great  right  lymphatic  ducts.  In  the  lowest  animals  the 
blood  itself  is  scarcely  a  higher  development  than  mere  lymph,  and 
in  none  of  the  invertebrata  do  lymphatic  vessels  exist.  In  the 
lowest  vertebrata,  also,  no  lymphatic  glands  are  found,  but  lymph- 
atic vessels  merely,  and  the  lymph  is  poured  directly  from  these 
into  the  nearest  veins. 

II.  Chyle. 

Chyle  is  the  fluid  obtained  from  the  lacteals  (lymphatics  of  the 
small  intestine)  and  the  thoracic  duct;  where  it  is,  however,  of 
course,  mixed  with  lymph.  It  results  from  the  digestion  of  certain 
elements  of  the  food ;  and  the  experiments  of  Bernard  would  prove 
that  it  is  derived  from  the  fatty  alone.  It  differs  in  appearance  with 
the  part  of  the  chyliferous  system  from  which  it  is  obtained,  and 
with  the  state  of  the  animal  as  to  having  been  lately  fed  or  not. 
Indeed,  lymph  alone  exists  in  the  lacteals  and  thoracic  duct  during 
fasting.     Chyle  also  varies  in  different  species  of  animals. 

Human  chyle  is  generally  a  milky,  opalescent,  yellowish  white 
or  pale  reddish  fluid,  with  a  saline  and  mawkish  taste,  and  an  alka- 
line reaction.  It  coagulates  into  a  very  soft,  friable  coagulum,  in 
about  ten  minutes  after  its  removal  from  the  vessels. 

Under  the  microscope,  the  chyle  shows — 1.  The  liquor  chyli : 
2.  The  morphological  elements. 

1.  The  liquor  chyli  (intercellular  fluid — Lehmann)  is  very  similar 
to  the  liquor  sanguinis,  especially  if  the  former  be  taken  for  exa- 
mination from  the  thoracic  duct.  The  amount  of  fibrine  in  human 
chyle  is  not  yet  precisely  ascertained,  but  it  augments  while  the 
chyle  is  passing  through  the  mesenteric  glands.  Subtracting  this 
element  from  the  liquor  chyli,  the  remainder  is  called  the  chyle- 
serum.  This  resembles  the  blood-serum  in  composition,  being,  how- 
ever, poorer  in  albumen,  while  it  is  richer  in  water,  fat,  extractive 
matters,  alkalies,  and  salts — especially  the  chlorides  of  sodium  and 
potassium.  Whether  it  is,  like  blood-serum,  free  from  iron,  is  not 
yet  positively  decided.  It  becomes  more  turbid  and  milky  if  more 
fat  is  taken  in  the  food,  but  not  otherwise,  whether  animal  or  vege- 
table food  be  taken.  The  fat,  however,  diminishes  while  the  fluid 
is  passing  through  the  mesenteric  glands;  partly,  doubtless,  from 


150  THE   FLUIDS. 

the  fact  that  it  is  required  for  the  development  of  the  cytoid  cor- 
puscles. 

2.  The  histological  elements  of  the  chyle  are — 1.  Extremely  minute 
granules;  2.  Coarse  granules;  3.  Distinct  nuclei  with  nucleoli ;  and 
4.  Cytoid  corpuscles.  It  is  only  during  digestion,  however,  that 
these  elements  appear  in  a  marked  degree. 

1.  The  granules  cover  the  field  of  view  like  a  minute  veil.  They 
constitute  what  Mr.  Gulliver  termed  the  molecular  base  of  the  chyle. 
Miiller  found  them  to  be  fat-granules  surrounded  by  a  proteine-like 
(albuminous?)  substance.  Probably  no  true  fat-glohules  normally 
exist  in  the  chyle.  To  this  molecular  base  of  the  chyle  its  turbidity 
and  milky  appearance  are  due.  It  is  more  abundant  in  proportion 
as  the  food  contains  more  fat. 

2.  The  coarse  granules  are  grouped  together'  and  appear  to  be 
held  in  contact  by  a  hyaline  substance.  {Muller) 

3.  The  nuclei  are  sharply  defined,  contain  nucleoli,  and  are  some- 
times covered  with  individual  granules.  {Kblliker) 

4.  The  cytoid  corpuscles  are  identical  with  those  of  lymph  (p.  148). 
It  is,  however,  an  interesting  fact,  that,  while  they  are  often  2  4'o(j  of 
an  inch  in  diameter  in  the  lacteals,  they  are  seldom  more  than  45'g^ 
to  3()'(j(j  in  the  thoracic  duct. 

Colored  blood-corpuscles  are  also  always  found  in  the  chyle  from 
the  thoracic  duct,  these  being  either  developed  there  from  the  cytoid 
corpuscles,  or  being  derived  from  the  lymphatics  of  the  spleen,  as 
already  explained  (p.  147). 

The  quantity  of  the  chyle  entering  the  blood  in  twenty-four 
hours  is  not  satisfactorily  settled.  Yierordt  estimates  it  at  5J 
pounds ;  Bidder  at  Q.Q  pounds,  as  already  stated  (p.  148). 

Origin. — Bernard  concludes  that  chyle  is  formed  by  the  digestion 
of  the  fat  alone  in  the  food.  If  this  be  true,  chyle  is  scarcely  other- 
wise than  mere  lymph,  with  an  addition  of  fat.  It  is,  however,  very 
certain  that  not  all  the  fat  in  the  food  is  converted  into  chyle  and 
absorbed  by  the  lacteals,  since  the  blood  of  the  vena  portse  is  almost 
twice  as  rich  in  fat  during  the  process  of  digestion  as  during  fast- 
ing. And,  on  the  other  hand,  it  is  probable  that  the  other  elements 
of  food,  besides  fat,  are  not  entirely  excluded  from  absorption  by 
the  lacteals,  since  the  albuminous  matters  of  the  chyle  are  more 
likely  to  have  been  admitted  with  the  fat  than  to  have  been  deve- 
loped from  the  latter  by  the  addition  of  nitrogen  from  the  blood  in 
the  mesenteric  glands,  as  has  been  suggested.     Since,  however,  the 


THE   BLOOD.  151 

albumen  and  fibrine  of  the  chyle  may  have  existed  in  the  lymph, 
or  have  been  absorbed  directly  from  the  bloodvessels,  it  is  not  yet 
necessary  to  controvert  the  conclusion  of  Bernard,  that  the  fat  alone 
of  the  food  is  directly  absorbed  by  the  lacteals  to  form  the  chyle. 

The  uses  of  the  chyle  need  not  be  enlarged  upon  after  the  pre- 
ceding remarks  upon  lymph.  Its  abundance  of  fat,  however,  ren- 
ders it  more  prolific  than  the  latter  in  the  development  of  the  cytoid 
corpuscles,  which  are  to  constitute  an  important  element  of  the 
blood ,  and  its  other  elements  also  are  developed  in  it,  as  prepara- 
tory to  their  admission  into  the  latter  fluid. 

III.  The  Blood. 

The  histological  relations  of  the  blood  are  all-important,  since 
the  elements  for  the  development  of  the  tissues,  and  for  the  forma- 
tion of  the  fluids,  except  chyle,  are  derived  from  it. 

Blood  is  distinguished  from  all  other  animal  fluids  by  its  bright 
cherry-red  color,  which,  however,  undergoes  certain  variations  in 
circumstances  anon  to  be  specified.  It  is  a  thick,  slightly  trans- 
lucent fluid,  with  an  alkaline  reaction.  Its  specific  gravity  is  from 
1045  to  1075 — averaging  1055 ;  being  less  in  women  than  in  men, 
in  children  than  in  adults,  and  in  pregnant  women  than  in  those 
not  so. 

Normal  blood  solidifies  or  coagulates  after  its  withdrawal  from 
the  vessels,  a  change  depending  on  its  fibrine,  and  whose  properties 
have  been  specified  on  page  90.  This  process  includes  three  pe- 
riods :  1.  The  blood  becomes  viscid  and  gelatinous  in  from  two  to 
four  minutes  after  its  withdrawal.  2.  After  seven  to  fourteen 
minutes  it  has  become  a  consistent  jelly.  3.  The  fibrine  contracts 
and  pours  out  from  its  fibrillated  network  a  thin,  colorless,  or  pale 
yellow  fluid,  the  serum,  which  rises  to  the  surface.  This  increases 
in  quantity  in  proportion  as  the  other  part,  the  clot,  contracts,  its 
contraction  continuing  for  a  time  varying  from  twelve  to  forty 
hours.  The  particulars  respecting  the  fibrillation  of  the  fibrine  in 
the  clot  have  been  stated  on  page  92,  and  the  microscopical  appear- 
ances have  been  represented  by  Fig.  43.  The  clot  consists  of  the 
fibrine  of  the  blood,  together  with  the  blood-corpuscles,  both  red 
and  colorless;  and  its  lower  part  is  of  a  darker,  and  the  upper  part 
of  a  brighter  red  than  the  original  blood.  Arterial  blood  coagu- 
lates more  rapidly  than  venous;  and  the  blood  of  women  more 
rapidly  and  less  firmly  than  that  of  men. 


152 


THE   FLUIDS. 


Seen  under  the  microscope,  while  circulating,  the  blood  consists 
(1)  of  a  fluid  portion — the  liquor  sanguinis — containing  (2)  histo- 
logical elements  of  two  kinds,  viz.,  the  white  and  the  red  corpuscles. 
Of  1,000  parts  of  blood,  510  to  520  are  corpuscles,  and  from  490  to 
480  are  liquor  sanguinis. 

1.  The  Liquor  Sanguinis, 

The  fluid  portion  of  the  blood,  called  the  liquor  sanguinis,  blood- 
plasma,  and  the  intercellular  fluid  [Lehmann),  consists  of  the  serum 
already  mentioned  and  the  fibrine.  Its  specific  gravity  varies  but 
little  from  1028.  It  contains  all  the  elements  necessary  for  the  de- 
velopment of  the  tissues,  viz.,  those  of  the  first  class,  fat,  and  the 
albuminous  compounds  of  the  third  class.  It  also  contains  many 
of  the  principles  of  the  second  class  resulting  from  the  metamor- 
phosis or  dis-assimilation  of  the  tissues,  as  urea,  creatine,  &c.  It 
may,  indeed,  be  regarded  as  a  solution,  in  903  parts  of  water,  of  97 
parts  of  the  principles  just  mentioned ;  for,  though  not  all  of  the 
latter  are  directly  soluble  in  water,  it  has  been  shown  that  all  are 
actually  in  solution  in  the  blood  (pp.  55  and  48). 

The  following  is  an  analysis  of  1,000  parts  of  liquor  sanguinis, 
by  Lehmann,  the  specific  gravity  being  1028 : — • 


Water 

Solid  constituents 


902.90 
97.10 


Fibrine 4.05 

Albumen 78.84  to  98. 

Fat 1.72 

Extractive  matters 3.94 

Mineral  Substances  (8.55). 


^     8.55 


Chlorine   . 

.       3.644 

Sulphuric  acid  . 

.       0.115 

Phosphoric  acid 

.       0.191 

Potassium 

.       0.323 

Sodium     . 

.      3.341 

Oxygen    . 

.       0.403 

Phosphate  of  lime    . 

.       0.311 

Phosphate  of  magnesia 

.      0.222 

The  fibrine  constitutes  4.05  in  1,000  of  the  plasma  alone,  and  from 
2  to  2.2  (about  3 — Lehmann)  in  1,000  of  the  whole  blood.    Arterial 


THE   BLOOD.  153 

contains  more  than  venous  blood.  There  is  but  little  in  the  portal 
vein,  less  in  the  splenic,  and  a  mere  trace  or  none  at  all  in  the  he- 
patic. We  shall  recur  (p.  158)  to  its  uses  in  the  blood,  and  its  rela- 
tions to  the  tissues,  after  speaking  of  the  other  elements  in  the 
plasma. 

The  serum  is  best  obtained,  in  its  isolated  state,  from  coagulated 
blood,  after  the  contraction  of  the  clot  has  ceased.  It  is  sometimes 
seen  to  contain  a  quantity  of  undissolved  particles  in  suspension, 
which  give  it  a  milky  appearance,  and  which  consist  of  fat-globules, 
granules  of  precipitated  albumen,  or  of  colorless  (cytoid)  blood- 
corpuscles. 

The  amount  of  water  in  the  serum  is  generally  directly  propor- 
tioned to  that  in  the  whole  blood,  and  inversely  to  the  number  of 
the  blood-corpuscles.  A  very  watery  serum,  however,  necessitates 
an  increase  of  water  in  the  individual  blood-corpuscles,  from  endos- 
mosis.  In  the  serum  of  the  blood  of  adult  males  it  averages  90.5 
per  cent.;  in  that  of  females,  especially  during  pregnancy,  somewj^at 
more.  Arterial  blood  contains  more  water  than  that  of  the  veins ; 
that  of  the  portal  vein,  however,  contains  the  most  water  of  all  of 
the  latter,  especially  during  digestion,  and  the  blood  of  the  hepatic 
vein  less  than  that  of  any  other  vessel.  The  serum  becomes  more 
watery  in  most  diseases,  except  in  the  first  stages  of  typhus  fever, 
measles,  scarlet  fever,  and  cholera.  The  blood  of  the  amphibia 
contains  more  water,  and  that  of  birds  less,  than  the  blood  of  the 
mammalia. 

The  principal  constituent  of  the  blood-serum  is  albumen,  of  which 
there  is  from  7.9  to  9.8  per  cent.;  and  from  63  to  70  parts^  in  1,000 
of  blood.  {Becquerel  and  Rodier)  Arterial  blood  contains  less  albu- 
men than  venous;  in  the  horse,  as  9.2  to  11.4.  (Lehmann.)  The 
blood  of  the  hepatic  vein  is  very  rich  in  it,  while  the  portal  vein 
has  still  less  than  the  arteries.  The  quantity  of  albumen  in  the 
blood  of  the  veins  increases  considerably  during  digestion.  Human 
blood  contains,  on  an  average,  more  albumen  than  that  of  most 
mammalia.  In  most  diseases  the  amount  of  albumen  is  diminished, 
it  having  been  found  increased  only  in  plethora,  intermittent  fever, 
and  cholera. 

It  is  not  yet  satisfactorily  demonstrated  that  caseine  exists  in  the 

'  This  includes  about  4  parts  of  albuminose.  {Robin  and  Verdeil.)  Lelimann's 
analysis  would,  however,  give  only  about  44  iu  1,000  parts  of  blood,  which  is  pro- 
bably nearer  the  fact. 


154  THE   FLUIDS. 

blood-serum  even  of  pregnant  women,  and  of  tlie  placental  vessels. 
The  "serum-caseine"  may  be  merely  albumen  deficient  in  alkali  and 
salts.  {Lehmann.) 

The  fats  of  the  serum  consist  principally  of  stearic,  oleic,  and 
margaric  acids,  and  cholesterine.  What  has  been  called  "seroline" 
is  a  mixture  of  the  crystallizable  part  of  these  fats ;  these  prepon- 
derating in  the  serum,  while  the  more  oily  and  yellow-colored  are 
found  in  the  red  corpuscles.  Phosphoretted  substances  soluble  in 
ether  do  not  exist  in  the  serum,  though  they  do  in  the  corpuscles. 
The  amount  of  fat  in  the  serum  is  not  precisely  determined,  but  it 
is  constantly  increased  during  digestion.  It  is,  on  the  average, 
more  abundant  in  the  serum  of  women  than  in  that  of  men.  The 
blood  of  the  veins  contains  more  fat  than  that  of  the  arteries,  and 
the  portal  vein  the  most  of  all  (p.  77).  In  diseases,  the  ordinary 
fats  appear  to  diminish,  while  the  cholesterine  increases. 

Glucose,  or  grape  sugar  (p.  70),  is  also  a  constituent  of  the  blood- 
sepum,  though  in  extremely  small  quantity.  After  the  use  of  amy- 
laceous or  saccharine  food  it  may  be  increased  to  0.5  per  cent.  The 
blood  of  the  hepatic  vein  abounds  in  sugar,  while  that  of  the  portal 
vein  contains  only  traces  of  it.  Bernard  has  found  that  the  glucose 
is  formed  in  the  substance  of  the  liver,  and,  sometimes  at  least,  from 
a  nitrogenized  material.  M.  Figuier's  statement,  that  the  sugar,  is 
formed  in  the  portal  vein  and  stored  up  in  the  liver,  has  not  yet 
been  confirmed. 

Ui'ea,  hippuric  acid,  creatine,  and  creatinine  exist  in  serum,  but  in 
iquantity  too  small  to  be  determined.  A  peculiar  yellow  coloring 
matter  has  also  been  supposed  to  exist  in  it,  but  this  is  not  decided. 

Formic,  acetic,  and  lactic  acids  may  also  exist  in  the  serum,  since 
the  first  is  formed  in  the  perspiration,  and  the  last  in  the  muscles ; 
but  they  have  been  detected  only  in  the  blood  of  the  splenic  vein. 
Hypoxanthine  has  been  found  in  the  blood  of  the  spleen.  It  occurs 
also  in  case  of  leucaemia ;  as  do  the  three  acids  just  mentioned,  and 
glutin. 

Biliary  coloring  matter  and  acids  occur  only  in  diseased  blood,  and 
sometimes  when  there  is  no  decided  lesion  of  the  liver.  Uric  acid 
has  been  found,  with  certainty,  only  in  diseased  blood,  especially  in 
arthritis. 

Of  the  mineral  constituents  of  the  serum,  the  chloride  of  sodium 
is  the  most  abundant,  averaging  61  per  cent,  of  the  ash.  Next  is 
carbonate  of  soda,  28.9  per  cent.      Chloride  of  potassium  varies 


THE   BLOOD.  156 

much,  but  averages  about  4  per  cent,  of  the  ash ;  the  phosphate  of 
soda  about  3  per  cent. ;  while  the  sulphate  of  potassa  depends  mostly 
on  the  manner  of  incineration.  The  salts  together  average  about 
.85  per  cent,  of  the  serum.  They  are  more  abundant  in  the  blood  of 
men  and  of  adults  than  in  that  of  women  and  children.  There  are 
more  salts  in  arterial  than  in  venous  blood,  except  that  of  the  portal 
blood,  which  contains  more  than  that  of  the  arteries.  In  case  of 
repeated  bleedings,  more  salts  are  found  in  the  blood  last  drawn 
than  in  the  first.  The  serum  salts  are  much  diminished  in  violent 
inflammations,  and  still  more  so  in  cholera ;  while  they  are  consi- 
derably increased  in  acute  exanthemata,  typhus,  dysentery,  Bright's 
disease,  and  especially  in  dropsy. 

The  carbonate  of  ammonia  is  found  in  the  blood  only  in  severe 
diseases,  and  especially  in  uraemia;  and  almost  always  in  the  blood 
of  cholera  patients. 

Origin. — The  liquor  sanguinis  is  derived  from  the  lymph  and  the 
chyle,  principally  from  the  latter. 

The  sources  from  which,  its  mineral  constituents  are  originally 
derived  have  been  specified  in  connection  with  each  of  the  imme- 
diate principles,  in  the  first  part  of  this  work.  The  fats  are  almost 
entirely  taken  in  the  food.  The  albumen  is  derived  directly  from 
albuminose ;  the  latter  being  formed  in  the  small  intestine,  as  has 
been  shown  (p.  87),  from  the  digestion  of  the  albuminous  sub- 
stances (albumen,  caseine,  and  fibrine)  and  the  peculiar  organized 
immediate  principles  (osteine,  musculine,  elasticine,  &c.)  of  the  food. 
The  fibrine  is  also  formed  at  once  from  the  albuminose,  or  from  the 
albumen  in  the  blood. 

Uses. — From  the  liquor  sanguinis  all  the  tissues  and  the  fluids, 
except  chyle,  are  formed,  unless  the  blood-corpuscles  also  have 
some  part  in  the  development  of  the  former ;  which  will  be  shown 
to  be  improbable  when  the  functions  of  the  corpuscles  are  discussed. 

Nor  is  it  difficult  to  decide  what  is  the  precise  function  of  each 
of  the  elements  of  the  liquor  sanguinis,  excepting  the  albumen  and 
the  fibrine.  The  water  is  indispensable,  both  as  a  solvent  of,  and 
as  a  vehicle  for  carrying,  the  blood  constituents  to  the  capillaries; 
and  it  also  enters  into  the  composition  of  all  the  solids  and  fluids 
of  the  body  (p.  45).  The  salts  are  essential  constituents  of  the 
tissues  and  the  fluids,  and  the  use  of  each  is  specified  in  the  first 
part  of  this  work.  E.  g.  common  salt  aids  in  the  assimilation  and 
the  dis-assimilation  of  the  tissues,  and  prevents  the  solution  of  the 


156  THE   FLUIDS. 

blood-corpuscles  in  the  serum  (p.  50).  The  phosphate  of  lime  is 
indispensable  for  the  formation  of  bone.  The /ate  are  also  required 
for  the  development  of  adipose  tissue,  and  the  formation  of  all  the 
fluids  containing  fat  (p.  77);  while  the  other  principles  of  the 
second  class,  as  urea,  creatine,  creatinine,  &c.,  result  from  the  dis- 
assimilation  of  the  tissues,  and  are  to  be  eliminated  from  the  blood, 
in  the  excretions,  as  effete  materials. 

In  regard  to  the  uses  of  albumen  and  fibrine,  it  is  generally 
asserted  by  authors  that  the  former  exists  in  the  blood  principally 
as  the  material  from  which  the  fibrine  is  formed,  though  it  also 
becomes  solidified  in  certain  organs  (especially  the  nervous  centres), 
and  forms  a  part  of  the  serous  secretions  and  the  transudations; 
while  the  fibrine  is  the  only  plastic  or  organizable  element  in  the 
liquor  sanguinis,  and,  therefore,  the  one  from  which  all  the  tissues 
are  formed. 

But  in  the  first  place,  it  is  impossible  that  any  single  immediate 
principle  can  be  the  source  of  all  the  tissues,  since  all  of  the  latter 
consist  of  several  of  these  principles  combined.  The  phosphate  and 
carbonate  of  lime  are  as  indispensable  in  the  formation  of  bone  as 
is  the  organic  substance  which  unites  with  them,  whether  it  be 
formed  from  fibrine  or  albumen.  Hence,  also,  both  albumen  and 
fibrine  naturally  have  these  salts  and  some  others  always  associated 
with  them  (pp.  84  and  90).  So  far  as  this  point  is  concerned,  therefore, 
albumen  may  be  a  plastic  element  as  well  as  fibrine ;  and  it  occurs 
at  once  as  improbable  that  all  the  tissues  can  be  developed  and 
nourished  from  an  element  constituting  only  about  ■^\^  part  {Leh- 
mann)  of  the  blood,  while  another  similar  immediate  principle  ex- 
ists in  at  least  twenty  times  ("nearly  twenty  times" — Lehmann)  that 
amount.  But  we  proceed  to  examine  the  grounds  of  the  view 
usually  entertained. 

1.  The  tissues  are  said  to  be  developed  and  nourished  from 
fibrine  only,  because  all  plastic  exudations  contain  fibrine.  If  this 
were  true,  we  might  also  remember  that  they  also  contain  albumen. 
But  Lehmann  asserts  that  plastic  exudations  are  sometimes  entirely 
deficient  in  fibrine.'  Fibrine,  therefore,  cannot  be  the  only  organ- 
izable element  in  the  liquor  sanguinis,  at  any  rate ;  albumen  must 
be  organizable  in  exudations  containing  no  fibrine.  And  if  so  in 
such  cases,  it  is  probably  in  all,  for  we  find  no  exudations  not 

'  Physiological  Chemistry,  vol.  ii.  p.  290. 


THE   BLOOD. 


157 


containing  albumen.  Gluge's  assertion,  that  "the  organization  of 
fibrinc  into  fibres  and  cells  is  a  matter  of  direct  observation,"  has 
already  been  quoted  (p.  119).  We  know  that  it  is  developed  into 
fibres  by  mere  coagulation,  but  have  shown  that  there  is  no  proof 
of  cells  being  developed  from  fibrine.  On  the  other  hand,  they  are 
probably  never  developed  from  fibrine,  but  from  albumen  rather; 
fibrine  never  rising  to  a  higher  organization  than  mere  simple  fibre. 
2.  It  is  asserted  that  false  membranes  are  at  first  formed  from 
organized  fibrine  alone,  and  that  this  is  subsequently  converted  into 
a  higher  tissue,  usually  some  modification  of  the  areolar.  It  is  true 
that  the  future  new  membrane  is  at  first  shadowed  forth  by  the 
fibrillated  fibrine.  The  latter  is,  however,  either  ultimately  reab- 
sorbed and  replaced  by 

other  permanent  tissues;  ^^s-  ^■** 

or  the  fibres  themselves 
remain,  and  present  the 
appearance  represented 
by  Fig.  9-i.  The  fibril- 
lated fibrine  constitutes 
the  matrix  or  nidus  in 
which  the  cells  and  other 
histological  elements  (if 
any)  are  developed  from 
the  albumen  and  other 
immediate  principles,  as 
there  is  every  reason  to 
believe ;  and,  having  per- 
formed    this     temporary 

function,  the  fibrine  usually  disappears.  If,  however,  no  other  his- 
tological elements  are  formed  in  it,  it  sometimes  remains.  The  fact 
is  undoubted  that  it  is  the  fibrine  which  is  organized  into  the  fibres, 
and  this  alone  shows  that  it  cannot  be  also  organized  into  higher 
elements  and  tissues;  for  every  histological  element  has  its  own 
identity  and  independent  vitality.  Hence  fibres  are  never  converted 
into  cells,  nor  any  one  tissue  into  another  (p.  82).  It  must,  there- 
fore, be  something  else  that  is  converted  into  cells  and  tissues,  and 
we  can  assign  no  other  element  than  the  albumen.  In  respect  to 
the  tissues,  therefore,  albumen,  and  not  fibrine,  is  the  i:)lastic  element 
of  the  blood-plasma.     Ordinarily,  however,  the  coagulated  fibrine 


A.  Fibres  in  flbro-cystic  tumor,  b.  After  addition  of  acetic  acid. 


158  THE    FLUIDS. 

must  shadow  forth  the  future  tissue  as  its  matrix,  and  hence  it  is 
almost  always  present  in  the  plastic  exudations. 

The  histological  relations  of  the  fibrine  in  the  liquor  sanguinis 
are,  therefore,  it  is  believed,  comprised  in  the  following  paragraphs 
(pp.  91  and  95): — 

1.  Fibrine  is  the  primum  organizatum  of  the  liquor  sanguinis,  the 
element  first  organized  in  the  plasma.  It  therefore  becomes  the 
matrix  or  nidus  in  which  other  and  more  permanent  tissues  are  de- 
veloped. This  is  also  the  fact,  whether  the  original  development 
of  the  tissues,  or  the  formation  of  pathological  new  growths,  or  the 
normal  reparative  process,  be  in  question.  Hence  the  blood  of 
pregnant  women  contains  an  increase  of  fibrine  (to  4.4  parts  in 
1,000)  during  the  last  two  or  three  months  of  pregnancy,  while  the 
tissues  of  the  foetus  (and  its  blood,  also)  are  being  most  rapidly 
developed  (p.  91). 

"2.  But  fibrine  has  also  a  not  less  important  relation  to  the  Mooditself. 
The  blood,  as  well  as  the  tissues,  has  its  own  vitality  to  maintain ; 
and  without  its  power  of  coagulation,  depending  on  its  fibrine,  the 
spontaneous  arrest  of  hemorrhage  would  be  impossible.  Nor, 
indeed,  could  art  long  restrain  it,  were  even  the  smallest  vessel 
divided,  without  the  aid  of  the  clot  invariably  formed  (p.  91). 
When  we  use  pressure  to  arrest  hemorrhage,  or  apply  a  ligature,  it 
does  so  merely  till  the  clot  is  formed  and  sufficiently  organized  to 
allow  of  the  removal  of  the  artificial  appliances. 

3.  Fibrine  is,  therefore,  a  peculiar  and  indispensable  element  of 
the  hlood^  merely  as  such ;  and  it  is  surprising  that  so  small  a  propor- 
tional amount  (^i^j  to  3^3),  has  the  power  to  secure  the  temporary 
solidification  of  all  the  blood  effused  in  hemorrhages.  Hence  it  may 
be  said,  indeed,  that  fibrine  exists  first  and  especially  for  the  advan- 
tage of  the  blood  alone ;  and  secondly,  for  the  benefit  of  the  tissues. 
Thus,  also,  it  appears  that  the  vitality  of  the  blood  inheres  in  the 
fibrine;  though  in  part  only,  as  will  appear  in  the  sections  upon  the 
blood-corpuscles.  Mr.  Simon  maintained  that  fibrine  is  an  excremeu- 
titious  matter.  Difficult,  however,  as  it  may  be  to  account  for  its 
increase  in  the  blood  in  certain  pathological  states,  we  are  obliged  to 
reject  at  once  the  idea  that  the  blood  owes  its  vitality,  in  part,  and 
its  power  of  self-preservation,  to  an  ejfete  substance  floating  in  it. 

On  the  other  hand,  albumen  is  the  great  histogenetic  element  of 
the  blood,  since  from  it  all  the  tissues  are  directly  formed.  Thus 
it  is,  indeed,  directly  the  pa6w?wm  of  the  tissues.     It  is  also,  pro- 


THE   BLOOD.  159 

bably,  the  source  of  the  fibrine  in  the  plasma ;  both  the  latter  and 
the  tissues  assimilating  it  to  themselves  (p.  86). 

2.  The  Blood-corpuscles. 
The  blood  of  the  lowest  animals  consists  of  a  fluid  merely,  the 
analogue  of  the  lic^uor  sanguinis  already  described.  As  we  ascend 
in  the  scale,  we  first  find  colorless  corpuscles  added  to  this  por- 
tion; and,  in' the  vertebrate  animals,  still  a  third  element,  also,  the 
colored  corpuscles. 

A.   The  Colorless  Corpuscles  of  the  Blood. 

The  colorless  corpuscles  of  the  blood  (lymph-corpuscles — Figs. 
95  and  96)  are  the  cytoid  corpuscles  already  described  (p.  145)  as 
existing  in  lymph,  chyle,  and  exuda- 
tions. They  are  far  less  numerous  ^'S-  95. 
than  colored  corpuscles  (1  to  346,  or 
even  400  in  adults'),  are  more  globu-  ^^  ^^  (^ 
lar,  though  not  perfectly  spherical, 
and  are  not  elastic.  They  average  ^  ^^ 
j^^OTj  o^  ^^  moh  in  diameter.  They 
have  a  granular  cell-membrane,  or 
capsule,  and  either  a  single  round  or  coioriess  wood-corpuscies.  (Magnified4oo 
reniform  nucleus,  or  several  small  nu-  '^"'^  ^"^^^ 
clei  heaped  upon  each  other.  They  are  lighter  than  the  red  cor- 
puscles, since  they  contain  a  larger  amount  of  fat,  and  are  also  de- 
ficient in  the  iron  contained  in  the  latter.  The  capsule  is  so  viscid, 
that  they  possess  a  well-marked  tendency  to  conglomerate  into  larger 
or  smaller  groups.  Hence,  while  circulating  in  the  capillary  vessels, 
they  are  seen  rolling  slowly  along  upon  the  internal  surface,  while 
the  red  corpuscles  move  rapidly  on  in  the  central  portion  of  the 
blood-column.    Their  quantitative  analysis  has  not  been  attempted. 

The  cell-memhrane^  or  capsule,  is  probably  an  albuminous  sub- 
stance. 

The  contents  of  the  cytoid  corpuscles  consist  of  an  albuminous 
solution,  containing  extremely  fine  granules  in  suspension,  most  ol' 
which  are  formed,  doubtless,  of  fat.  A  distinct  molecular  motion 
is  produced  in  them  by  the  endosmotic  action  of  water. 

'  Moleschott  finds  the  proportion  in  children  2^  to  12  years  old,  as  1  to  226  ;  at 
22  years,  1  to  330  ;  30  to  50  years,  1  to  346  ;  60  to  80  years,  1  to  381  ;  women  when 
menstruating,  1  to  247 ;  not  menstruating,  1  to  389  ;  in  pregnancy,  1  to  2S1. 


160  THE   FLUIDS. 

The  nuclei  are  single,  double,  triple,  or  multiple.  They  are  ren- 
dered more  visible  by  the  action  of  water,  but  dilute  acetic  acid 
exposes  them  by  dissolving  the  cell-wall. 

The  size  of  the  colorless  corpuscles  is  varied  by  the  endosmotic 
action  of  the  fluid  portion  of  the  blood ;  hence  the  richer  the  blood 
is  in  water,  the  larger  they  are,  and  vice  versa  (p.  145). 

The  cytoid  corpuscles  of  the  blood  are  more  abundant  in  young 
animals,  and  after  venesection ;  and  in  the  blood  of  pregnant  women 
during  the  last  months  of  pregnancy.  They  are  also  more  abun- 
dant in  venous  blood.  {KoUiker.)  An  abnormal  development  of 
them  constitutes  leuccemia.  Pyeemia,  also,  is  scarcely  distinguish- 
able from  the  latter,  since  the  pus-corpuscle  is  not  to  be  distin- 
guished from  that  under  consideration,  as  will  be  shown  under  the 
head  of  "Pus." 

Origin. — The  colorless  blood-corpuscles,  like  all  other  cytoid  cor- 
puscles (p.  146),  are  originally  developed,  by  free  cell-development, 
in  the  lymph,  the  chyle,  and  perhaps  also  the  liquor  sanguinis. 
Secondarily,  however,  new  cells  may,  doubtless,  be  developed  from 
pre-existing  ones,  and  thus  their  multiplication  seems  actually  to 
occur.  Lehmann  states  that  they  are,  "under  certain  conditions, 
doubtless  formed  in  the  liver ;  but  their  formation,  or,  at  all  events, 
their  development  and  growth,  are  not  confined  to  any  one  definite 
locality,  but  proceed  in  the  vessels  of  very  different  organs."    Kdl- 

liker  maintains  that  the  cytoid  cor- 

Fig-  96.  puscles  of  the  chyle  originate  in  the 

rt  minutest  lacteals.   He  there  found  nu- 

>Bp         &     a         ^  ^^®^'  ^i^^®^  ^^^^  o^  surrounded  by  gran- 

^         •  ^        ules,  and  very  fragile  young  cells,  with 

walls  almost  touching  the  nucleus,  and 
states  that  they  increase  in  size  on 
their  way  to  the  thoracic  duct.  In  the 
latter  he  found  none  of  these  nuclei, 
but  two  kinds  (larger  and  smaller)  of 
lymph-granules;  and  maintains  that 
Colorless  blood-corpuscles  in  various    the  smallci  ooly  are  convcrtcd  into 

phases,    a.a.  Stellate  form  occasionally        ,  t     i  i         i  i  i  -i        ^i 

.een  after  escape  of  their  contents.     b,h.       the     Icd     blood-COrpUSClcS,     whllc     the 

Free  nuclei,    c.  A  nucleus  surrounded    Jargcr  arc  gradually  dissolvcd  in  the 

by  a  few  granules.  d,e.  Small  cells,  fiome  rrn  •     '  T_  c     ^      • 

with  a  distinct  nucleus. /,  jr.  Larger  cells,      blood.        Thc    VanOUS   phaSCS    01    their 

one  with  a  visible  nucleus,  h.  Similar    development  arc  showu  lu  Fig.  96. 

cell  after  addition  of  water,     i.  Similar  ■••  _  _  "    _ 

coll  after  addition  of  acetic  acid.  UsCS. IllStologically,  the  Cytoid  COI- 


THE   BLOOD.  161 

puscles  of  the  blood  (especially  the  smaller)  may  be  regarded  as 
merely  a  transitional  stage  of  development  of  the  red  corpuscles. 
The  idea  of  Kcilliker,  however,  that  they  are  not  all  converted  into 
the  colored  corpuscles  in  the  human  body,  is  confirmed  by  com- 
parative histology ;  since  in  all  the  white-blooded  animals  they  are 
arrested  in  their  development,  and  form  no  colored  corpuscles, 
though  they  are  in  some  animals  quite  abundant. 

The  manner  in  which  the  red  corpuscles  are  developed  from 
those  under  consideration  will  be  specified  in  the  following  section 
(p,  168).  But  it  should  be  here  added  that  even  in  the  white-blooded 
animals  they  cannot,  during  their  development  and  their  metamor- 
phosis, be  without  influence  on  the  composition  of  the  blood,  and 
thus,  directly  or  indirectly,  on  the  development  and  the  metamor- 
phosis of  the  tissues.  Besides,  they  will  incidentally  secure  a 
patulous  condition  of  the  minute  vessels,  and  thus  subserve  the 
circulation  of  the  liquor  sanguinis  in  these  species.  The  former 
remark  may  also  be  applied  to  the  human  cytoid  corpuscles,  since 
they  are  living  cells  manifesting  an  active  interchange  of  matter 
with  the  blood-plasma. 

To  them,  therefore,  as  well  as  to  the  fibrine,  the  blood  owes  its 
vitality.  Those  who  maintain  that  fibrine  is  the  pahulum  of  all  the 
tissues,  have  suggested  that  the  colorless  corpuscles  elaborate  fibrine 
from  the  albumen  in  the  blood.  This  is  quite  improbable;  for 
though  the  amount  of  fibrine  and  the  number  of  colorless  corpuscles 
are  sometimes  simultaneously  increased  (as  in  inflammation),  there 
are  no  grounds  for  the  opinion  that  these  cells  contain  any  fibrine 
at  all.^  In  leuc£emia,  also,  the  cells  are  abnormally  numerous 
(even  one  to  three  red  blood-corpuscles),  while  the  fibrine  is  not 
increased ;  and  the  same  is  also  true  of  the  blood  of  young  and 
growing  animals.  They  are,  therefore,  to  be  regarded  as  entirely 
independent,  histologically,  of  fibrine,  and  their  increase  or  dimi- 
nution must  be  attributed  to  causes  acting  independently  upon 
them.  Wherever  growth  is  going  on,  cytoid  corpuscles  appear — 
e.  g.  in  new  formations,  reparative  or  otherwise,  or  in  the  original 
development  of  the  tissues — and  it  might  be  expected  that  they 
would  be  developed  rapidly  in  the  blood  also  of  young  animals,  as 
one  of  its  normal  constituents ;  its  metamorphosis  being  rapid,  as 

'  An  increase  of  fibrine  in  tlie  blood  is  perhaps  always  attended  by  an  increase 
of  wbite  corpuscles,  but  the  converse  of  this  does  not  hold. 
11 


162 


THE   FLUIDS. 


Fig.  97. 


well  as  that  of  the  tissues.  On  the  other  hand,  in  leuccemia  there 
appears  to  be  rather  a  general  arrest  of  development  of  the  white 
corpuscles,  and  thus  a  great  proportional  diminution  of  the  colored 
ones.  That  the  cytoid  corpuscles  of  the  blood  are  also  liable  to  dis- 
ease, especially  to  fatty  degeneration,  is  a  fact  recently  established 
by  the  investigations  of  Wedl  and  others. 

B.  The  Colored  Blood-corpuscles. 
The  colored  blood-corpuscles  (red  corpuscles,  blood-cells,  blood- 
disks — Fig.  97),  which,  in  their  natural  or  moist  state,  constitute  510 

to  520  parts  in  1,000  of  blood,  and 
about  one-half  of  its  mass,  are  thick, 
circular,  slightly  biconcave  disks,  ave- 
raging 33L3  of  an  inch  Q^'^^  to  5 J^^, 
Hassall)  in  diameter.  Their  thickness 
at  the  circumference  is  about  one-fifth 
of  their  diameter.  Their  specific  gra- 
vity is  1088.5  to  1088.9  in  men,  and 
1086  to  1088  in  women.  They  consist 
of  a  colorless  cell-membrane,  with  red, 
or,  by  transmitted  light,  yellow  viscid  contents.  Some  of  them  are 
also  originally  found  to  contain  one  or  more  amorphous  granules, 
but  none  ever  contain  a  nucleus.  The  corpuscles  of  the  embryo 
are  somewhat  larger  than  they  are  after  birth.  All  the  mammalia 
have  circular  and  discoid  blood-corpuscles,  except  the  camel,  the 
dromedary,  and  the  lama,  in  which  they  are  elliptical  and  biconvex. 
In  birds  the  corpuscles  are  long  and  oval,  elevated  in  the  centre, 
and  thick  at  the  margin ;  in  the  amphibia  they  are  oval  and  very 
convex.  Those  of  most  mammalia  are  smaller  than  those  of  man, 
while  those  of  the  amphibia  are  far  larger — in  some  cases  (the  pro- 
teus)  3^5  of  an  inch  in  diameter. 

The  following  are  the  mean  dimensions  of  the  blood -corpuscles  of 
several  of  the  lower  animals,  compared  with  man  {Schmidt) : — 


Colored  blood-corpuscles.    (Magnified 
400  diameters.) 


Man   . 

•  s-^hs 

Mouse 

•    4T5S 

Elephant   .  ^^^^ 

Dog    . 

'    ^3^0 

Ox     . 

•    4  5's? 

Frog  ^^^toyg'^g 

Kabbit 

•    ?B50 

Cat     . 

•    ?50^ 

Siren     .     .    5^5 

Rat     . 

•    400U 

Horse 

•  it'ttj 

Proteus      .    ^ijj 

Pig     • 

•    it's  5 

Sheep 

•    Sl\^ 

It  is  evident  that  the  blood-corpuscles  and  their  viscid  contents 
must  have  a  different  composition  from  the  intercellular  fluid,  or 


THE   BLOOD. 


163 


liquor  sanguinis,  in  which  they  float.  The  following  is  Lehmann's 
analysis  of  1,000  parts  of  corpuscles,  the  specific  gravity  being 
1088,5,  the  water  being  to  the  solids  as  2.14  to  1,  and  the  or- 
ganic to  the  inorganic  constituents  as  40  to  1. 

One  thousand  parts  of  blood-corpuscles  contain — 


Water  .... 

.       688.00 

1 

Solids  .... 

.      312.00  f 

Hsematine     .... 

.      16.75 

Globuline  and  cell-membranes      .         .         .    282.22 

Fat       ...         . 

2.31 

Extractive  matters 

2.60 

Mineral  substances  without 

iron  (8.12). 

Chlorine 

1.686  ^ 

Sulphuric  acid 

0.066 

Phosphoric  acid    . 

1.134 

Potassium     . 

3.328 

-    8.12 

Sodium 

1.052 

Oxygen 

.667 

Phosphate  of  lime 

.114 

Phosphate  of  magnesia 

.073  , 

The  cell-memhranes,  once  erroneously  believed  to  be  fibrine,  when 
isolated,  form,  in  the  moist  state,  a  whitish-gray  adhesive  mass,  which 
has  not  a  fixed  composition.  [Lehmann.)  In  the  hepatic  veins  the 
cell-membranes  are  distinguished  from  those  of  all  other  vessels  in 
not  being  made  entirely  to  disappear  by  the  addition  of  water. 
They  are,  probably,  an  albuminous  substance ;  but  not  fibrine,  nor 
the  deutoxide  of  protein,  as  has  also  been  stated. 

The  viscid  contents  of  the  blood-corpuscles  have  been  said  to  con- 
sist principally  of  the  coloring  matter  called  hsematine,  held  in  solu- 
tion by  the  globuline.  Lehmann,  however,  terms  it,  as  a  whole, 
hoemaio-crystaUine.  We  prefer  the  term  hcemaio- globuline  (p.  96). 
There  is  from  18  to  26  per  cent,  of  dry  hasmato-globuline  in  the 
moist  corpuscles ;  in  the  whole  blood,  from  9  to  12  per  cent.  But 
the  hsematine  and  globuline  do  not  stand  in  a  definite  numerical 
relation  to  each  other.  The  insoluble  ferruginous  substance  called 
hsematine  does  not  exist  as  such  in  the  blood,  but  is  a  product  of 
the  transformation  of  the  actual  blood-pigment  (p.  103).  In  the 
blood  the  latter  is  soluble,  and  it  is  calculated  to  constitute  16  to  17 


164  THE   FLUIDS. 

per  cent,  of  the  contents  of  the  blood-corpuscles  of  an  adult  man. 
'The  iron  in  the  ash  of  the  corpuscles  belongs  to  the  hcematine 
alone,  and  varies  with  it — constituting  6.64  per  cent,  of  the  htema- 
tine,  and  4.348  per  cent,  of  the  dry  corpuscles.  {Schmidt})  But  a 
considerable  part  of  the  fats  of  the  blood  is  also  contained  in  the 
red  corpuscles — their  quantity  amounting  to  .2  or  .3  per  cent,  of  the 
moist  cells.  It  appears  that  more  fat  is  found  in  the  cells  of  venous 
than  of  arterial  blood.  The  so-called  extractive  matters  also  exist 
in  the  blood-corpuscles;  of  which,  however,  neither  the  amount 
nor  their  precise  composition  is  known.  Of  the  mineral  constitu- 
ents of  the  blood-corpuscles,  the  phosphates  and  the  combinations 
of  potassa  are  in  great  excess  over  the  chlorine  and  the  sodium 
combinations.  The  common  salt  is  confined  almost  entirely  to  the 
serum  of  the  blood,  as  already  shown.  The  cells  of  arterial  blood 
always  contain  more  salts  than  those  of  venous  blood ;  but  those 
of  the  hepatic  vein  are  especially  rich  in  them.  Finally,  the  gases 
of  the  blood  are  especially  contained  in  the  corpuscles.  These  are 
carbonic  acid  gas,  oxygen,  and  nitrogen.  Whipped  blood  absorbs 
1|  times  its  volume  of  carbonic  acid  gas,  and  only  15  per  cent,  of 
its  volume  of  oxgen.  Nitrogen  is  not  more  largely  absorbed  by 
blood  than  by  water,  and  about  equal  quantities  are  found  in  arte- 
rial and  venous  blood.^  There  is  only  more  oxygen  relatively  to 
carbonic  acid  in  arterial  than  venous  blood ;  the  proportions  being 
in  the  former  as  6  to  16,  and  in  the  latter  as  4  to  16.  That  these 
gases  exist  in  great  part  in  the  blood,  and  especially  in  the  cor- 
puscles, in  a  chemical  combination,  though  a  loose  one,  is  no  longer 
doubtful  {Lehmann);  there  being  from  11  to  14  times  the  amount 
that  could  be  taken  up  by  mere  mechanical  absorption.  The  hoe- 
mato-globuline  manifests  a  remarkable  affinity  for  them.  There  are 
other  gases,  however,  as  carbonic  oxide  and  several  carbo-hydro- 
gens,  which  combine  with  the  corpuscles  so  energetically  as  to 
blacken  or  even  to  destroy  them.  It  has  already  been  stated  that 
the  gases  in  the  blood  are  in  Su  fluid  state  (pp.  43,  44). 

'  The  metallic  iron  constitutes  1  part  to  230  of  dry  corpuscles,  1  to  229  in 
women,  1  to  248  in  pneumonitis,  1  to  260  in  chlorosis,  and  1  to  249  in  pregnancy ; 
in  the  first  stage  of  typhus,  1  to  220.  The  blood-cells  in  the  hepatic  veins  con- 
tain but  two-thirds  as  much  iron  as  those  in  the  vena  portae.  In  hydraemia  the 
cells  contain  an  excess  of  peroxide  of  iron ;  the  globuline  being  diminished,  and 
thus  the  hsematine  relatively  increased.  (Schmidt.)  Berzelius  found  less  iron  than 
Scliiiiidt  in  the  dry  corpuscles.    (See  p.  102.) 

*  Robin  and  Verdeil  say  1^  times  as  much  in  arterial  as  in  venous  blood. 


THE   BLOOD. 


165 


Fig.  98. 


Wliippcd  blood  also  contains  certain  morphological  elements 
called  fibrinous  fialces.  Thej  do  not,  however,  consist  of  fibrine, 
but  are  more  allied,  chemically,  to  horny  substances ;  consisting  of 
epithelial  cells,  partly  from  the  inner  coat  of  the  vessels,  and  partly 
of  fragments  from  the  cuticle  of  the  observer,  as  Briich  suggests, 
which  have  fallen  into  the  blood.  The  fragments  of  destroyed  cell- 
membranes  have  also  been  mistaken  for  them. 

The  cell-membrane  of  the  blood-corpuscles  being  powerfully  en- 
dosmotic,  the  latter  undergo  changes  of  form  from  currents  between 
their  contents  and  the  intercellular  fluid,  and  hence,  also,  changes 
in  specific  gravity.  The  latter,  of  course,  increases  when  water  is 
abstracted  from  them,  and  vice  versa.  Evaporation,  or  the  addition 
to  the  blood  of  small  quantities  of  neutral  alkaline  salts,  sugar,  or 
gum,  may  remove  a  part  of  the  water;  when  they  may  present  the 
shrivelled  appearance  represented  by 
Fig.  98.  Eepeated  bleedings  also  in- 
crease the  specific  gravity  of  the  blood- 
corpuscles.  (Lehmann.) 

On  the  other  hand,  an  increase  of 
water  in  the  corpuscles  diminishes  their 
specific  gravity,  and  may  distend  them 
till  they  become  almost  spherical,  or 
even  burst.  Hence  their  lower  specific 
gravity  in  anasmia.  They  are  also 
lighter  when  they  contain  an  excess  of 
fatty  granules. 

These  changes  in  the  weight  and  the  form  of  the  blood- cells  affect 
both  their  tendency  to  sink  in  the  plasma  (and  thus  modify  the  ap- 
pearance of  the  clot),  and  also  modify  the  color  of  the  blood. 

1.  The  "tendency  to  sink"  is  increased  by  an  increased  specific 
gravity  of  the  corpuscles;  and,  apparently,  also  by  an  excess  of  car- 
bonic acid  in  the  corpuscles,  and  a  diminished 
quantity  of  albumen  in  the  serum.  At  least, 
the  blood  in  inflammations  manifests  the  pecu- 
liarities of  composition  just  mentioned ;  and  in 
this  state,  also,  the  corpuscles  sink  more  rapidly 
than  those  of  healthy  blood.  The  effect  of  this 
peculiarity  on  the  color  of  the  clot  has  been 
alluded  to  (p.  93).  The  aggregation  of  the  siood-corpuscies  in  nnm- 
corpuscles  into  nummular  rolls  (Fig.  99)  seems    '""'"''  'f '•  ^"^'^''^  '"^ 

•^  \      o  /  tirely  adherent  at  a,  and 

to  be  a  consequence,  rather  than  a  cause,  of  this    partiauy  at  6. 


Blood-corpuscles  shrivelled  by  chemical 
agents. 


Fig.  99. 


166  THE   FLUIDS. 

increased  tendency  to  sink,  since,  on  sinking,  tliey  necessarily  apply 
their  broad  sides  to  each  other. 

2.  The  precise  color  of  the  blood,  as  a  whole,  depends  very  much 
on  the  shape  of  the  blood-corpuscles,  and  therefore  indirectly  upon 
physical  conditions,  some  of  which  have  been  already  mentioned. 
While  the  corpuscles  retain  the  biconcave  form,  their  color  is 
lighter ;  when  distended  by  endosmosis  so  as  to  become  biconvex, 
they  disperse  the  light  more,  and  thus  render  the  blood,  as  a  whole, 
darker.  Hence  all  substances  abstracting  water  from  the  blood-cells 
without  decomposing  them,  and  thus  rendering  their  central  de- 
pression more  distinct,  produce  in.  it  a  bright  red  to  a  vermilion 
color — as  all  neutral  alkaline  salts,  solutions  of  sugar,  &c.;  while 
those  agents  which  render  them  more  nearly  spherical — as  water, 
ether,  and  dilute  organic  acids — give  to  the  blood  a  dark  bluish-red 
color.  Still,  the  form  alone  does  not  always  determine  the  color ; 
for  the  blood-cells  of  the  amphibia  are  naturally  biconvex,  and  can- 
not become  biconcave,  and  yet  they  are  colored  bright  red  by  the 
solutions  of  sugar  and  of  the  salts  mentioned  above.  The  following 
salts  produce  a  vermilion  color  in  the  blood  of  the  mammalia,  of 
birds,  and  of  the  amphibia :  sulphates  of  potash  and  soda,  nitrates 
of  potash  and  soda,  chloride  of  potassium,  phosphate  of  soda,  car- 
bonate and  bicarbonate  of  soda,  ferro-cyanide  of  potassium,  borax, 
iodide  of  potassium,  sulpho-cyanide  of  potassium,  sal  ammoniac, 
sulphate  of  magnesia,  &c. 

But  the  ihichiess  of  the  cell-memhrmies,  and  their  amount  of  folding, 
must  also  influence  the  color  of  the  blood.  If  the  cells  are  collapsed, 
the  membrane  is  thicker  and  folded ;  if  distended,  they  are  thinner 
and  smooth.  In  the  latter  case,  the  coloring  matter  shines  through 
in  its  natural  hue,  which  is  a  very  dark  red ;  as  in  a  thin  milk-glass 
a  dark  red  fluid  still  appears  so,  but  in  a  thick  one,  light  red.  Hence 
the  darker  color,  usually,  of  venous  blood,  and  the  fact  that  all  sub- 
stances which  corrugate  the  cell-membranes  render  the  blood  dark 
red,  as  acetic  acid,  the  alkalies,  &c.  The  above-mentioned  salts,  when 
found  experimentally  to  give  a  brighter  color  to  the  blood  of  the 
amphibia,  are  seen  to  wrinkle  the  large  blood-cells.  According  to 
some,  oxygen  also  contracts,  and  carbonic  acid  gas  expands  the  cor- 
puscles ;  and  herein  is  another  cause  of  the  bright  color  of  arterial, 
and  the  darker  hue  of  venous  blood.  It  is  also  found  that  if  even 
colorless  solid  substances  strongly  reflecting  light  are  mixed  among 
the  corpuscles,  they  give  to  the  mass  of  blood  a  brighter  red  tinge. 


THE   BLOOD. 


167 


Hence  the  bright  color  of  the  fatty  blood  of  drunkards ;  and  the 
blood  in  leucaemia  is  also  bright  red,  since  the  cytoid  corpuscles, 
in  which  it  abounds,  strongly  reflect  the  light. 

Thirdly,  it  must  be  admitted  that  chemical  combinations  with  the 
blood-pigment,  especially  of  oxygen  and  carbonic  acid,  affect  the 
color  of  the  blood ;  the  former  rendering  it  lighter,  and  the  latter 
darker  colored.  Indeed,  all  the  salts  which  at  first  contract  the 
blood -cells,  and  reader  the  blood  lighter  colored,  entirely  dissolve 
the  in  when  in  a  more  concentrated  solution,  and  then  give  to  the 
blood  a  deep  dark-red  hue. 

The  proportional  amount  of  the  moist  corpuscles  has  already 
been  generally  stated  at  510  to  520  in  1,000;  the  extremes  in  adults 
being  472  and  542,  and  the  average  512.  The  blood  of  women,  how- 
ever, especially  in  pregnancy,  contains  a  smaller  proportion  of  them, 
which  is  also  diminished  by  repeated  losses  of  blood  and  other 
fluids.  Of  the  lower  animals,  the  blood  of  swine  contains  the 
greatest  amount  of  corpuscles ;  that  of  the  amphibia  comparatively 
few  of  them. 

The  enumeration  of  the  blood-cells  has  been  recently  attempted 
by  Yierordt  and  Welcker,  and  it  is  found  that  from  42,700,000  to 
45,500,000  corpuscles  exist  in  a  single  cubic  line  of  healthy  human 
blood!  [Lehmaim.)  Assuming  the  whole  amount  of  blood  to  be 
20  pounds,  their  whole  number  is  about  65  billions  and  570,000 
millions.     They  are  more  numerous  in  venous  blood.  {Kolliker) 

In  former  analyses,  the  blood-corpuscles  were  previously  dried, 
and  were  then  found  to  constitute  about  140  parts  out  of  1,000  of 
blood.  The  following  is  the  analysis  of  Becquerel  and  Rodier, 
showing  the  elements  in  the  liquor  sanguinis  and  corpuscles,  taken 
together;  the  mean  being  given  for  both  men  and  women: — 


Man. 

Woman 

Water    .         .        .        .        . 

779.0  ) 
221.0  ) 

791.1 

Solid  constituents    . 

208.9 

Fibrine 

2.2 

2.2 

Corpuscles       .         .        .        . 

141.1 

127.2 

Albumen^        .        .        .        . 

69.4 

70.5 

Eat^ 

1.6 

1.6 

Extractive  and  salts  of  serum  . 

6.8 

7.4 

'  This  is  too  liigh  an  estimate  for  the  albumen.     (See  note,  page  153.) 

^  The  amount  of  fat  in  the  blood  is  not  sensibly  affected  by  its  amount  in  the  food. 


168 


THE   FLUIDS. 


Origin. — The  blood-cells  first  formed  in  the  embryo  appear  to 
have  their  origin  in  the  primordial  cells  of  the  germinal  structure ; 
some  of  these  developing  tissues,  and  others  becoming  isolated  and 
metamorphosed  into  blood -cells.  These  also  are  multiplied  by 
bipartite  division  (p.  126).  But  in  the  human  embryo  the  first 
brood  of  corpuscles  disappears  entirely  by  the  end  of  the  second 
month,  when  the  lymph  and  chyle  begin  to  be  poured  into  the 
blood,  and  when  they  are  superseded  by  those  developed  from  the 
lymph  and  chyle-corpuscles.  {Paget)  The  first  blood-cells  are 
larger  than  the  subsequent  ones;  being  about  o^^o  ^^  ^^  mah.  in 
diameter,  and  nucleated.  The  nucleus  is  ^-qq-q  of  an  inch  in  diame- 
ter, central,  circular,  very  little  prominent  on  the  surface  of  the  cell, 


Development  of  first  set  of  red  corpuscles  (mammalian  embryo),  a.  Dotted  nucleated  and  nucle- 
olated  embryo'^cell.  b.  Same  with  a  dividing  nucleus  ;  the  division  being  complete  at  c.  At  D, 
the  cell  also  is  dividing,     e.  Cell  still  containing  a  few  granules,     r.  Perfect  blood-corpuscle. 


Fig.  101. 


'A. 


Phases  of  the  red  blood- 
corpuscle  (man),  a  and  6. 
Colorless  corpuscles  or  gran- 
ule-cells in  the  coarsely  and 
the  finely  granular  state,  c 
and  d.  Nucleated  cells  with- 
out and  with  color,  e.  Free 
cellffiform  nucleus,  or  perfect 
red  corpuscle. 


and  slightly  granular  or  tuberculated.  Fig. 
100  shows  the  several  stages  of  their  develop- 
ment. 

The  doctrine  that  the  continued  development 
of  the  red  corpuscles  occurs  from  the  colorless 
corpuscles  of  the  blood,  is  the  most  plausible, 
though  open  to  some  objections.  Mr.  Whar- 
ton Jones  has  shown  that  in  the  whole  animal 
kingdom  five  forms  of  blood-corpuscle  are  to 
be  met  with  (which  are  represented  by  Fig. 
101),  viz:  1.  Coarse  granule-cells  (a);  2.  Fine 
granule-cells  (h) ;  3.  Colorless  nucleated  cells 
(c) ;  4.  Colored  nucleated  cells  {d) ;  5.  Colored 
non -nucleated  cells  (e),  or  perfect  red  cor- 
puscles of  man  and  the  mammalia.     These 


THE   BLOOD.  169 

five  forms  are  believed  to  correspond  to  as  many  stages  of  develop- 
ment. The  third  form  (the  colorless  nucleated  cell)  is,  however,  the 
highest  stage  of  development  in  the  white  blood  of  the  invertebrate 
animals.  The  "colored  nucleated  cell"  (fourth  stage)  is  the  highest 
form  in  the  oviparous  mammalia;  while  the  "colored  non-nucleated 
cell"  is  the  perfect  blood-cell  of  the  mammalia.  It  does  not,  how- 
ever, follow  that  the  human  blood-cell  passes  through  the  five  stages 
mentioned  by  Mr.  Jones,  nor  that  any  stage  corresponds  precisely 
with  one  of  these.  There  is,  however,  a  general  correspondence 
not  without  interest.  The  following  account  of  their  development 
is  extracted  from  Mr.  Paget's  lectures,'  and  which  may  be  accepted 
as  the  most  reliable  hitherto.    Fig.  102  represents  the  five  stages  of 


Development  of  the  red  from  the  colorless  corpuscles  of  the  blood,  a.  Cytoid  corpuscle,  b.  Same, 
heing  converted  into  a  red  corpuscle,  c.  Cytoid  corpuscle  with  its  membrane  raised  by  the  action 
of  water,  d.  Same,  having  lost  most  of  its  granules,  e.  Same,  acquiring  color ;  a  single  granule 
remaining  like  a  nucleus,    f.  Perfect  red  corpuscle. 

development  of  the  colorless  into  the  colored  cell ;  though  the  im- 
probability has  already  been  remarked  that  all  the  cytoid  corpuscles 
are  thus  transformed  (p.  161): — 

"The  white  corpuscle,  at  first  tuberculated,  containing  many  gran- 
ules, and  darkly  shaded  (a),  becomes  smoother,  paler,  less  granular^ 
and  more  dimly  shaded  or  nebulous  (b).  In  these  stages  the 
cell- wall  may  be  easily  raised  from  its  contents  by  the  contact  and 
penetration  of  acetic  acid,  or  by  the  longer  action  of  water  (c) ;  and, 
according  to  the  stage  of  development,  so  are  the  various  appear- 
ances which  the  contents  of  the  cell  thus  acted  on  present.  In  the 
regular  progress  of  development,  it  becomes  at  length  impossible 
to  raise  the  cell- wall  from  its  contents  (d).    Then  the  corpuscles 

'  On  the  Life  of  the  Blood.     1848. 


170  THE   FLUIDS. 

acquire  a  pale  tinge  of  blood  color,  and  this  always  coincides  witli 
the  softening  of  the  shadows  which  before  made  them  look  nebu- 
lous, and  with  the  final  vanishing  of  all  the  granules,  with  the  ex- 
ception sometimes  of  one,  which  remains  some  time  longer  like  a 
shining  particle  in  the  corpuscle,  and  has  probably  been  often  mis- 
taken for  a  nucleus  (e).  The  blood  color  now  deepens,  and  at  the 
same  rate  the  corpuscles  become  smooth  and  uniform ;  biconcave, 
having  previously  changed  the  nearly  spherical  form  for  a  lenticular 
or  flattened  one ;  smaller,  apparently  by  condensation  of  their  sub- 
stance, for  at  the  same  time  they  become  less  amenable  to  the  influ- 
ence of  water;  more  liable  to  corrugation  and  to  collect  in  clusters; 
and  heavier,  so  that  the  smallest  and  fullest  colored  corpuscles 
always  lie  deepest  in  the  field  (f).  Thus  the  most  developed  state 
of  the  mammalian  red  corpuscles  appears  to  be  that  in  which  they 
are  full-colored,  circular,  biconcave,  small,  uniform,  and  heavy.  This 
is  the  state  in  which  they  appear  to  live  the  longer  and  the  most 
active  part  of  their  lives."* 

It  will  be  observed  that  Mr.  Paget  regards  the  mature  blood- cor- 
puscles not  as  mere  free  nuclei,  as  some  observers  have  done  (p.  115), 
but  as  non-nucleated  cells.  The  blood-cells  of  the  amphibia  are, 
however,  always  nucleated. 

The  idea  maintained  by  Weber  and  others,  that  the  liver  is  the 
special  agent  in  the  development  of  the  blood-cells  in  the  embryo, 
appears  to  be  applicable  to  oviparous  animals,  but  not  to  the  mam- 
malia. The  fact,  however,  that  the  blood  of  the  hepatic  vein  in 
man  contains  a  much  greater  amount  of  blood-cells  than  does  that 
of  the  vena  portee,  indicates  that  they  are  developed  with  peculiar 
activity  in  that  organ.  This,  however,  may  be  a  mere  consequence 
of  the  fact  that  the  blood  of  this  vein  is  also  rich  in  colorless  cor- 
puscles, and  which  undergo  their  development  while  in  the  hepatic 
vessels,  independently  of  any  peculiar  action  of  the  liver  itself. 

Thus  the  life  of  the  blood  is  seen  to  inhere  in  the  red  corpuscles, 
the  colorless  corpuscles,  and  the  fibrine  (pp.  158  and  161). 

Function. — The  view  which  ascribes  to  the  red  corpuscles  the 
function  of  absorbing  oxygen  while  in  the  lungs,  and  giving  it  par- 
tially off  in  the  capillaries,  while  they  also  absorb  carbonic  acid  in 
the  capillaries,  and  give  it  off  in  the  air  expired  from  the  lungs, 

'  The  necessity  of  fatty  elements  in  aid  of  the  development  of  the  blood-cells  is 
inferred  from  their  composition,  already  stated.  Hence,  also,  their  rapid  formation 
from  the  use  of  cod-liver  oil,  as  observed  by  Popp. 


THE   BLOOD.  171 

has  been  controverted  by  the  observations  of  Hannover  (p.  103)  and 
Marchand;  though  Lchmann  regards  it  as  "completely  proved." 
The  fact  that  chlorotic  persons  exhale  as  much  carbonic  acid  as 
those  in  health,  may  be  explained  by  the  supposition  that,  there 
being  a  certain  amount  to  be  removed,  each  corpuscle  absorbs  more 
than  in  health ;  and  the  fact  that  the  liquor  sanguinis  always  ab- 
sorbs a  part  of  this  gas.  It  is  also  very  certain  that  a  part  of  the 
oxygen  taken  up  by  the  blood-cells  is  only  mechanically  absorbed, 
while  a  part  (and  probably  the  greater  portion)  acts  chemically  upon 
their  constituents.  Lehmann  found  that  after  the  inspiration  of 
oxygen  the  mineral  substances  and  the  hasmatine  in  the  blood-cor- 
puscles increased,  while  the  organic  substances,  and  more  especially 
the  fats,  were  considerably  diminished ;  the  latter  being  destroyed 
by  oxidation,  and  their  effete  products  being  transferred  to  the 
intercellular  fluid,  or,  at  all  events,  undergoing  a  considerable  loss 
of  weight  by  the  formation  of  carbonic  acid  and  water.  Heat  is 
also  evolved  in  connection  with  the  formation  of  the  latter. 

The  blood-cells,  therefore,  have  a  direct  relation  to  the  function 
of  respiration  (aeration),  and  to  the  rapidity  of  the  metamorphosis 
and  repair  of  the  tissues.  Hence,  in  the  different  species  of  animals, 
we  find  a  direct  ratio  between  the  normal  amount  of  the  blood-cells 
in  the  blood,  the  activity  of  the  aerating  process,  the  waste  of  the 
tissues  and  their  repair  (and,  of  course,  the  amount  of  food  required), 
and  the  natural  (or  organic)  heat  of  the  organism.  But  the  oxygen 
merely  mechanically  contained  in  the  blood -cells  also  leaves  the 
latter  in  the  capillaries  and  combines  with  the  tissues,  thus  securing 
their  metamorphosis  also,  and  again  developing  heat. 

At  present,  therefore,  we  must  regard  the  blood-cells  as  the  great 
agents  for  effecting  the  dis-assimilation  of  the  tissues,  and  of  the 
blood  itself.  And  since  vital  phenomena  are  impossible  without  a 
constant  metamorphosis  of  the  molecules  of  the  tissues  manifesting 
them,  the  blood-cells  are  indispensable  in  all  the  more  active  species 
of  the  animal  kingdom,  and  incidentally  the  natural  temperature  of 
each  is  proportioned  to  their  activity.  Still,  the  corpuscles  are  only 
the  special^  but  not  the  sole  carriers  of  oxygen ;  the  blood-plasma 
also,  to  some  extent,  possessing  that  power.  Hence  the  slow  dis- 
assimilation  and  low  temperature  of  the  invertebrata  may  be  secured 
without  them.  In  some  of  the  latter,  also,  Avhich  possess  a  high 
degree  of  activity  (as  the  insects),  the  corpuscles  are  not  required, 
since  oxygen  is  brought  into  direct  contact  with  all  their  tissues 


172  THE   FLUIDS. 

through  the  ramifications  of  the  tracheae,  which  open  upon  the  sur- 
face of  their  bodies. 

Lehmann's  idea,  that  the  blood-cells  are  laboratories  in  which  the 
individual  constituents  of  the  plasma  are  prepared  for  the  higher 
function  of  aiding  in  the  formation  and  reproduction  of  the  tissues, 
is  scarcely  tenable,  since  the  nutrition  of  the  tissues  is  equally  per- 
fect, so  far  as  can  be  perceived,  in  animals  whose  blood  is  destitute 
of  this  histological  element.  Indeed,  that  the  red  corpuscles  have 
any  direct  relation  to  the  formation  of  the  tissues,  is  very  impro- 
bable; c?{5-assimilation  and  the  consequent  development  of  vital 
force  being,  it  is  believed,  their  special  function. 

We  have  no  certain  knowledge  of  the  length  of  time  the  blood- 
cells  exist.  Since  the  cells  of  the  same  blood  differ  in  the  length 
of  time  during  which  they  resist  chemical  agents,  it  is  probable  that 
the  more  easily  decomposed,  and  which  are  usually  of  a  deeper 
color,  are  the  older ;  while  the  paler  and  less  easily  acted  upon,  and 
which  present  in  their  granules  the  rudiments  of  a  nucleus,  are  of 
more  recent  origin.  That  their  regeneration  is  not  very  rapidly 
effected  is  probable,  from  the  fact  that  the  blood  is  poor  in  corpuscles 
for  several  days  after  a  moderate  venesection,  and  exhibits  a  great 
deficiency  of  them  for  a  prolonged  period  after  repeated  bleedings; 
and  since  there  is  a  copious  supply  of  colorless  corpuscles  after 
severe  losses  of  blood.  If,  however,  they  are  slowly  regenerated, 
they  cannot  have  a  very  short  existence,  since  otherwise  the  num- 
ber of  the  colored  cells  would  not  so  far  exceed  that  of  the  colorless 
corpuscles.  (Lehmann.) 

Whether  the  blood-cells  are  disintegrated  in  one  particular  part 
or  organ,  is  not  yet  satisfactorily  decided.  Schult  designated  the 
liver,  and  Kolliker  the  spleen,  as  the  organ  where  this  process  is 
effected.  On  the  other  hand,  Gerlach  and  Schaffuer  regard  the 
spleen  as  the  organ  in  which  the  corpuscles  are  formed.  Scherer's 
investigations  confirm  the  idea  of  Kolliker.  If  there  be  a  particu- 
lar organ  in  which  the  corpuscles  are  formed,  and  another  in  which 
they  are  disintegrated  and  dissolved — which  is  still  very  doubtful, 
however — we  should  mention  the  liver  as  the  former,  and  the  spleen 
as  the  latter  (p.  170). 

•  Quantity  of  Bhod  in  the  Human  Body. 
Very  different  estimates  of  the  whole  amount  of  blood  have  been 


THE   BLOOD.  173 

made,*  it  being  usually  stated  that  its  weight  constitutes  one-fifth  of 
that  of  the  whole  body.  Ed.  Weber  has,  however,  recently  insti- 
tuted some  experiments,  according  to  which  only  one-eighth  of  the 
weight  of  the  body  is  blood,  or  18  pounds  for  a  man  weighing  144 
pounds.  Lehmann  calculates  that  the  whole  amount  of  blood  in  a 
young  man  is  17|  to  19  pounds.  The  estimate  of  Weber  appears 
to  be  the  most  accurate  hitherto  made.  It  is  calculated  that  only 
one-third  of  the  whole  blood  can  be  lost  rapidly  without  fatal  con- 
sequences. But  much  more  than  this  may  be  ultimately  lost  by 
frequently  recurring  hemorrhages,  the  vessels  thus  having  time  to 
adapt  themselves  to  the  diminished  amount  of  their  contents,  so 
that  the  circulation  is  still  maintained. 

Yarieties  in  the  Composition  of  the  Blood  in  different  Physiological 

Conditions. 

1.  Sexual  varieties.  The  blood  of  women  is  of  a  lighter  red  color 
than  that  of  men.  is  specifically  lighter,  contains  more  water,  and 
evolves  a  less  intense  odor  of  perspiration  when  treated  with  1\ 
times  its  volume  of  sulphuric  acid.  It  generally  contains  less  cor- 
puscles, but  the  same  amount  of  fibrine  {Lehmann) ;  and  some  more 
serum  in  proportion  to  the  clot.  It  usually  contains  more  albumen 
and  salts  (especially  the  soluble),  and  less  fat  and  extractive  matters. 

2.  In  pregnancy  the  blood  is  darker  than  usually,  is  richer  in 
water  and  poorer  in  corpuscles  and  albumen,  and  therefore  speci- 
fically lighter.  There  are  no  certain  data  respecting  the  fats  and 
salts ;  but  the  fibrine  is  relatively  increased  in  the  last  months,  and 
the  clot  is  generally  very  small,  witb  a  superficial  stratum  of  fibrine 
frequently  resting  upon  it  (p.  158). 

3.  Varieties  depending  on  age.  The  blood  of  new-horn  infants 
abounds  in  solid  constituents,  especially  blood-corpuscles  and  iron, 
while  it  is  poor  in  fibrine  and  salts.  It  contains  about  the  same 
amount  of  fat  and  albumen  as  in  the  adult,  and  a  much  larger  pro- 
portion of  extractive  matters.  In  advanced  life^  and  in  the  female 
after  tbe  cessation  of  the  catamenia,  the  blood  is  poorer  in  corpuscles, 
and  the  serum  loses  in  some  of  its  constituents,  but  the  cholesterine 
increases. 

4.  During  digestion^  both  the  plasma  and  the  cells  become  richer 
in  solid  constituents ;  though  the  latter  experience  a  relative  loss 

'  Blumenbach.  estimates  it  at  8J  to  10  pounds  ;  Reil  at  even  44  pounds. 


174  THE   FLUIDS. 

in  haematine.     The  fibrine  coagulates  more  slowly,  and  is  richer  in 
fat;  the  serum  is  denser,  sometimes  even  exhibiting  a  milky  tur- 
bidity from  an  abundance  of  fat-globules  (Fig. 
Fig.  103.  103)  and  cytoid  corpuscles.   The  fat,  albumen, 

extractive  matters,  and  the  salts  of  the  serum 
are  also  pretty  uniformly  augmented. 


5.  Among  the  lower  animals,  the  blood  of 
the  omnivora  (hog,  &c.)  is  the  most  abundant 
in  corpuscles  (and  therefore  in  soluble  phos- 
phates of  iron);  birds  are  next  in  order;  then 
Fat-globules  in  blood.  the  camivora  and  the  herbivora.  Of  fibrine, 
the  blood  of  birds  contains  the  most;  then 
that  of  the  omnivora,  herbivora,  and  the  carnivora.  Of /a^,  the  blood 
of  birds  also  contains  most ;  then  the  carnivora  and  the  herbivora. 
The  blood  of  the  mammalia  contains  more  albumen  than  that  of 
birds.  The  solid  constituents  of  the  serum  also  preponderate  in  the 
omnivora.  In  the  cold-blooded  vertebrata  (fishes  and  amphibia),  the 
blood  is  poorer  in  corpuscles  and  richer  in  water  than  in  the  warm- 
blooded. 

Normal  Differences  in  Composition  of  the  Blood  in  different  Vessels. 

A.  In  arterial  blood  the  red  corpuscles  are  less  numerous  than  in 
venous  blood  {Kolliker),  and  contain  more  water  and  less  solid  con- 
stituents; though  they  have  relatively  more  h^ematine  and  salts, 
but  far  less  fat.  The  white  corpuscles  are  also  less  numerous.  {Kol- 
liker.) The  intercellular  fluid  of  the  arteries  is  richer  in  fibrine 
than  that  of  venous  blood,  and  its  serum  contains  somewhat  more 
water  and  less  albumen'  and  fats;  while  their  extractive  matters  are 
slightly  increased,  and  the  salts  still  more  so.  Arterial  blood  also 
contains  more  oxygen,  but  only  relatively  to  its  carbonic  acid  gas 
(p.  164).  It  absolutely  contains  more  of  both  these  gases  than 
venous  blood,  and  about  the  same  amount  of  nitrogen  (pp.44, 164). 

B.  The  blood  of  certain  veins  is  peculiar. 

1.  The  portal  vein.  During  digestion,  if  sufficient  drink  has  been 
taken  with  the  food,  the  portal  blood  is  rich  in  intercellular  fluid 
and  in  water,  and  the  number  of  blood-cells  is  therefore  small.  The 
fibrine  is  slightly,  and  the  fat  considerably,  increased;  while  the 
albumen,  extractive  matters,  and  salts  are  moderately  so.  Compared 
with  the  blood  of  the  jugular  vein,  the  portal  blood  is  poor  in  cells 

'  In  the  solid  constituents  alone  of  the  serum,  an  equal  quantity  of  albumen  is 
found  in  arterial  and  venous  blood.    {Lehmann.) 


THE   BLOOD,  175 

and  in  solids  generally.  The  cells  are  also  partly  flocculent,  easily 
distorted,  and  soon  become  jagged  after  their  removal  from  the 
body,  are  richer  in  hasmatine  and  poorer  in  globuline,  and  contain 
twice  as  much  fat.  The  intercellular  fluid  contains  a  less  quantity 
of  a  fatty  fibrine ;  while  the  serum  contains  less  solid  constituents 
generally  (especially  albumen),  but  more  fat  and  extractive  matters 
and  more  salts  than  any  other  vessel.  Biliary  substances  have  not 
been  found  in  portal  blood,  and  sugar  only  seldom  occurs. 

2.  The  blood  of  the  hepatic  vein  differs  much  from  that  of  any 
other  vessel.  Compared  with  the  portal  vein,  it  is  poor  in  water ; 
as  3  to  4  during  digestion,  and  as  5  to  12  after  it.  Its  clot  is  volu- 
minous, and  easily  falls  to  pieces ;  and  it  contains  less  serum,  in  the 
proportion  of  15  to  34.  It  is  far  richer  in  both  cytoid  and  colored 
corpuscles,  the  former  presenting  every  variety  of  size  and  form, 
and  the  latter  forming  heaps  of  a  purplish-red  color.  The  cell- walls 
of  the  latter  are  also  less  easily  destroyed  than  those  of  the  blood 
generally  (p.  163),  and  the  proportional  amount  of  moist  blood-cells 
in  the  blood  of  the  hepatic  and  the  portal  veins  is  as  317  to  141. 
The  latter  are,  however,  poorer  in  fat  and  richer  in  salts,  and  espe- 
cially poor  in  heematine,  or  at  least  in  iron  (two-thirds  as  much  as 
in  the  vena  portas),  but  somewhat  richer  in  extractive  matters. 
Still,  they  have  a  greater  specific  gravity,  though  lighter  in  relation 
to  the  serum,  since  the  intercellular  fluid  is  far  more  dense,  and  con- 
tains much  more  of  the  solid  constituents  (as  11.8  to  8.4).  The 
latter  is,  however,  either  wholly  deficient  in  fibrine,  or  only  con- 
tains a  scarcely  perceptible  trace  of  it ;  and  contains  less  albumen^ 
and  fat,  and  much  less  salts,  with  considerably  more  extractive 
matter,  including  sugar. 

3.  The  blood  of  the  splenic  vein  has  been  analyzed  in  horses  by 
Mr.  Gray.'^  Compared  with  that  of  the  jugular  vein,  it  contains 
more  water,  iron  and  fat,  and  more  albumen  and  fibrine.  There  is 
also  less  solid  residue  in  the  serum,  which  always  presents  a  dark- 
reddish  tinge,  and  the  corpuscles  are  very  much  diminished, 

c.  The  blood  of  the  placental  vessels  contains  but  little  albumen 

'  The  serum  of  the  blood  of  the  hepatio  vein  contains  bnt  two-thirds  as  ranch 
albumen  as  is  found  in  the  portal  vein.  The  remaining  one-third  received  from 
the  portal  vein  has  probably  been  assimilated  in  the  development  of  the  blood- 
cells  which  abound  in  the  blood  of  the  hepatic  vein. 

^  On  the  Structure  and  Use  of  the  Spleen.     London,  1854. 


176  THE   FLUIDS. 

and  fibrine  {Stas),  but  a  large  amount  of  serum-caseine.    Stas  also 
found  urea  in  tliis  blood. 

D.  Zimmerman n  found  the  serum  of  tlie  blood  of  tbe  veins  of  the 
lower  extremities  poorer  in  water  tlian  that  of  the  upper  extremities. 

E.  The  menstrual  fluid  is  to  be  regarded,  histologically,  merely  as 
a  hemorrhage^  periodically  recurring  from  the  interior  of  the  uterus, 
and  therefore  as  pure  hhod.  It  is,  however,  discharged  per  vaginam 
in  a  state  of  admixture  with  the  mucus  of  the  cervix  uteri  and  the 
vagina,  and  therefore  contains  epithelial  cells  and  cytoid  corpuscles. 
(Fig.  109.)  Jul.  Vogel  states  that  menstrual  blood  contains  no  fibrine. 
On  the  other  hand,  E.  H.  Weber  found  coagulated  blood  on  the  mu- 
cous membrane  of  a  young  girl  who  had  committed  suicide  during 
the  catamenial  period.  The  fact  that  in  ordiuary  circumstances  the 
menstrual  fluid  does  not  coagulate,  has  generally  been  attributed  to 
the  action  of  the  acid  mucus  of  the  vagina,  and  not  to  the  absence 
of  fibrine,  the  former  holding  the  latter  in  solution.  Certain  it  is, 
that  where  the  menstrual  flow  is  so  increased  as  to  constitute  a  pa- 
thological condition  (menorrhagia),  there  is  no  deficiency  either  of 
fibrine  or  of  coagula. 

Pathological  States  of  the  Blood  in  certain  Diseases. 

1.  Inflammation.  The  changes  in  the  intercellular  fluid  in  inflam- 
mation are  these :  1.  In  all  inflammations  accompanied  by  a  febrile 
reaction  there  is  an  increase  of  fibrine  (hyperinosis),  it  ranging  from 
4.7  to  10.5  parts  in  1,000  of  the  blood.  The  highest  increase  occurs 
in  acute  rheumatism  and  pneumonitis.  It  may  be  considerable 
when  the  inflammation  is  not  extensive,  as  in  erysipelas ;  but  in 
each  particular  disease  it  is  proportioned  to  the  degree  and  duration 
of  the  inflammation.  It  is  independent  of  the  strength  of  the  pa- 
tient, and  of  the  increase  or  decrease  of  the  other  solid  constituents 
of  the  blood,  occurring  in  the  most  decided  anaemia  or  hydrasmia, 
and  as  abundantly  in  meningitis  and  other  acute  cerebral  diseases  as 
in  inflammation  of  other  parts.  2.  The  albumen  is  somewhat  dimi- 
nished in  inflammatory  blood.  The  serum  also  frequently  becomes 
turbid  from  the  presence  of  separated  albumen.  {Scherer.)  3.  There 
is  less  chloride  of  sodium  in  inflammatory  than  in  normal  blood,  but 
the  sulphate  of  soda  and  of  potassa  are  increased. 

The  red  corimscles  are  diminished  in  violent  inflammation  (rheu- 
matism and  pneumonitis),  but  not  in  any  marked  degree  unless 
other  pathological  conditions  coexist  to  induce  a  simultaneous  dimi- 

'  Those  who  maintain  that  this  fluid  is  an  exudation,  or  an  effusion,  overlook 
the  fact  that  the  blood-corpuscles  can  leave  the  vessels  only  after  a  rupture  of  their 
walls.     See  next  chapter,  on  "Effusions"  and  "Exudations." 


THE   BLOOD.  177 

nution  of  the  whole  mass  of  blood-cells.  In  some  cases  scarcely 
any  diminution  is  observed.  Still,  the  carbonic  acid  in  the  red  cor- 
puscles is  increased  in  inflammatory  blood,  as  are  also  the  colorless 
coj-jmscles;  and  the  former  manifest  an  increased  tendency  to  sink. 

The  diminution  of  the  solid  constituents  of  the  blood  is  usually 
proportioned  to  the  violence  of  the  inflammation  and  the  quantity 
of  exudation  thrown  off".  If  there  be  but  a  small  amount  of  the 
latter,  they  may,  indeed,  be  rather  augmented  than  diminished. 

Finally,  inflammatory  blood  coagulates  slowly,  and  the  clot  usually 
presents  the  buflfy  coat  (p.  93),  and  often  the  "cupped"  apjDcarance 
also. 

2.  Fever.  Becquerel  and  Eodier  found  the  blood  in  fever  to  be 
generally  somewhat  richer  in  water  than  in  the  normal  state,  and 
the  phosphorized  fats  and  cholesterine  to  be  especially  increased ; 
while  the  phosphates  are  also  considerably  so.  The  blood-corpuscles 
are  slightly  diminished  in  number.  Fibrine,  extractive  matters,  and 
soluble  salts  occur  in  the  normal  amount.  In  simple  ejjhemeral  and 
remittent  fever,  however,  the  albumen,  as  well  as  the  cholesterine,  was 
increased.  In  slight  iyitermittent  fever  they  found  the  fibrine  usually 
diminished,  while  Zimmermann  found  it  usually  normal.  In  marsh 
fevers  the  fibrine,  albumen,  and  fats  are  diminished,  and  the  blood- 
corpuscles  are  increased. 

In  typhus  (also  including  typhoid)  the  blood  exhibits  no  changes 
warranting  us  in  regarding  it  as  a  dyscrasia.  From  the  fifth  to  the 
eighth  day  it  is  very  similar  to  that  of  plethora.  From  the  ninth  day 
it  undergoes  a  great  change,  being  specifically  lighter,  chiefly  from 
a  diminution  of  the  corpuscles;  though  the  solid  constituents  of  the 
serum  also  diminish  daily  through  the  disease,  with  a  rapidity  pro- 
portioned to  the  intestinal  affection.  The  salts  and  extractive  mat- 
ters are  relatively  increased,  rather  than  absolutely  diminished. 

3.  Cholera.  In  this  disease  the  whole  blood  is  especially  dense 
and  viscid.  The  fibrine  is  unchanged;  the  serum  is  denser,  and 
poorer  in  water  and  salts.  Eelatively,  however,  it  is  richer  in  salts, 
and  very  rich  in  albumen.  But  it  contains  more  potash  salts,  and 
phosphates  than  normal  serum,  with  some  urea,  and  an  extractive 
substance  which  rapidly  converts  urea  into  carbonate  of  ammonia. 

The  blood-corpuscles  are  augmented — from  613  to  559  in  1,000 
in  men,  and  from  400  to  464  in  women.  {Schmidt)  This  increase 
is,  however,  relative,  since  many  blood-cells  are  actually  destroyed. 
They  are  also  poorer  in  salts,  and  their  proportional  amount  of  water 
is  diminished  (2.14  to  1.77).  The  proportion  of  organic  to  inorganic 
constituents  is,  however,  increased — from  44.1  to  58.1.  The  specific 
gravity  of  the  corpuscles  is  increased  in  men  to  1102.6. 

4.  Dysentery.  In  this  disease  the  corpuscles  are  fewer  and  lighter, 
their  specific  gravity  being  but  1085.5.  The  fibrine  is  usually  in- 
creased, the  solids  of  the  serum  decreased,  especially  the  albumen, 
and  the  salts  considerably  increased. 

12 


178  THE   FLUIDS. 

5.  In  the  acute  exanthemata  there  is  a  diminution  of  the  blood- 
cells,  and  increase  of  the  intercellular  fluid.  The  serum  is  denser 
than  usual,  and  its  salts  more  augmented  than  the  organic  substances. 

6.  In  puerjyeral  fever  there  is  considerable  diminution  of  the  co- 
lored corpuscles ;  the  fibrine  is  increased,  is  soft  and  gelatinous,  and 
almost  always  forms  a  crust.  In  most  cases  the  solid  constituents 
are  considerably  diminished,  though  sometimes  increased.  Bile- 
pigment  is  occasionally,  and  free  lactic  acid  not  unfrequently,  met 
with ;  the  blood  sometimes  also  having  an  acid  reaction. 

7.  Brie/Jit's  disease.  The  blood-cells  and  the  constituents  of  the 
serum  are  diminished.  The  specific  gravity  of  the  former  is  often 
reduced  to  1084.5.  Cholesterine  and  the  salts  of  the  serum  are, 
however,  increased.  On  an  average,  there  is  more  fibrine  than  in 
normal  blood. 

8.  In  plethora  the  blood-cells  are  rather  more  numerous,  and  the 
albumen  is  somewhat  increased.  In  other  respects  the  blood  is 
nearly  or  quite  normal. 

9.  Hydrcemic  blood  is  very  much  attenuated,  pale,  watery,  and 
forms  a  loose,  infiltrated,  gelatinous  clot. 

10.  Ancemia.  The  character  of  the  blood  depends  much  on  the 
cause  of  the  anaemia.  In  respect  to  the  diminution  of  the  blood- 
cells,  it  corresponds  with  the  blood  of  hydrsemia  and  chlorosis. 

11.  In  chlorosis  the  blood  forms  a  solid  clot,  covered  with  a  buffy 
coat,  and  floating  in  a  large  quantity  of  serum.  The  corpuscles  and 
iron  are  both  diminished,  in  a  small  or  an  excessive  degree,  without 
any  relation  to  the  intensity  of  the  disease.  The  fibrine  is  nearly 
normal ;  the  albumen  is  increased  only  relatively  to  the  cells. 

12.  In  leuccemia  the  blood  is  pale  red,  often  marked  with  whitish 
streaks,  is  rich  in  colorless  blood-corpuscles  (even  one  of  these  to 
three  colored  cells),  and  has  an  alkaline  reaction,  though  the  fluid 
filtered  from  the  clot  is  acid.  It  contains  true  glutin,  a  body  which 
ranks  between  glutin  and  albumen,  hypoxanthine,  and,  finally, 
formic,  acetic,  and  lactic  acids. 

13.  In  pyoimia  the  fibrine  is  diminished,  and  the  colorless  blood- 
cells  augmented.  This  state  is  difficult  to  distinguish  from  leu- 
caemia. 

14.  In  carcinoma  there  is  an  increase  of  fibrine.  The  blood-cells 
are  slightly  diminished. 

15.  In  diabetes  there  is  simply  an  increase  of  sugar  in  the  blood. 

16.  Etherization.  The  immediate  efiect  of  the  inhalation  of  ether 
seems  to  be  to  make  the  blood  richer  in  water  and  fat,  and  poorer 
in  blood-corpuscles. 

Finally,  in  regard  to  variations  in  the  amount  of  particular  ele- 
ments of  the  blood  in  diflcrent  diseases,  the  following  may  be  re- 
garded as  established : — 

1.  The  fibrine  is  increased  (hyperinosis)  in  all  inflammations  and 
in  carcinoma.     An  increase  also  occurs  during  the  last  months  of 


SEROUS  SECRETIONS.  179 

pregnancy.    It  is  diminished  (hypinosis)  slightly  in  intermittent  and 
marsh  fevers,  and  in  pyajmia, 

2.  The  albumen  of  the  blood  is  increased  in  plethora,  in  intermit- 
tent fevers,  after  drastic  purgatives,  and  in  cholera.  It  is  diminished 
in  simple  ephemeral  fevers  (slightly),  in  severe  inflammations,  in  the 
later  stages  of  typhus,  in  scurvy,  malaria,  puerperal  fever,  dysentery, 
Bright's  disease,  and  dropsy  from  organic  affections. 

3.  The  extractive  matters  are  increased  in  puerperal  fever  and 
scurvy. 

4.  The  salts  of  the  serum  (and  especially  the  chloride  of  sodium) 
are  increased  in  all  cases  in  which  the  albumen  is  diminished  {Schm^idt) ; 
hence  in  dysentery,  acute  exanthemata,  Bright's  disease,  typhus,  and 
especially  in  dropsy.  They  are  diminished  in  inflammation,  and  still 
more  so  in  cholera. 

6.  The  colorless  corjyuscles  are  increased  in  inflammation,  leucae- 
mia, and  pyaemia,  and  after  repeated  losses  of  blood. 

6.  The  colored  corpuscles  are  increased  in  plethora,  in  cholera,  in 
the  first  stages  of  heart-disease  and  the  first  eight  or  ten  days  of 
typhus,  and  in  marsh  fever.  They  are  diminished  in  violent  in- 
flammations, in  dysentery,  anaemia,  the  last  stages  of  typhus,  in. 
hydrgemia,  chlorosis,  puerperal  fever,  acute  exanthemata,  Bright's- 
disease,  carcinoma,  and  scurvy.  Their  specific  gravity  is  increased 
in  cholera  (to  1102.6),  and  diminished  in  albuminuria  (to  1084:.5) 
and  dropsy  (to  1081.19). 

The  number  of  the  red  corpuscles  is  also  diminished  by  prolonged 
fasting^  and  extreme  losses  of  blood  or  of  other  fluids;  while  the 
plasma  becomes  poorer  in  albumen  and  other  organic  constituents, 
but  richer  in  salts;  the  whole  blood  becoming  much  the  same  as  in 
anaemia.  Similar  results  are,  moreover,  produced  by  substances 
interfering  with  digestion,  or  the  formation  of  blood,  especially  the 
preparations  of  lead,  acids,  &c. 


CHAPTER   II. 

SEROUS   SECRETIONS,  TRANSUDATIONS,  AND   EXUDATIONS. 

Secretion  implies  a  separation  of  certain  elements  from  the 
blood  by  the  direct  action  of  cells.  It  is,  therefore,  a  vital  action, 
and  not  dependent  on  mere  physical  agencies.  In  the  case  of  se- 
creting membranes,  the  secreting  cells  always  constitute  an  epithe- 
lium upon  its  free  surface.     By  the  bursting  of  the  secreting  cells, 


180  THE   FLUIDS. 

the  contained  fluid  is  set  free,  and  is  then  recognized  as  the  proper 
secretion  of  the  surface  on  which  it  is  found. 

Transudation,  on  the  other  hand,  is  merely  a  physical  phenome- 
non, dependent  upon  the  permeability  of  membranes,  by  certain 
elements  of  the  blood  contained  in  their  vessels ;  and  must  not  be 
confounded  with  the  vital  process  before  defined.  The  word  effu- 
sion is  sometimes  used  to  express  the  same  phenomenon. 

Exudation  is  also  a  vital  process,  as  will  appear. 

I.  The  Serous  Secretions. 
Lehmann  has  included  all  the  serous  secretions  under  the  head 
of  transudations.  This  is,  however,  incorrect,  since  it  has  been 
proved  that  the  normal  serous  secretions  are  separated  from  the 
blood  by  the  epithelial  cells  of  the  serous  membranes.  The  serous 
surfaces  are,  however,  very  liable  to  transudations  also ;  and  in  all 
cases  where  an  excessive  amount  of  fluid  is  accumulated  in  a  serous 
cavity,  a  transudation  (or  an  exudation,  which  consists  of  the  blood- 
plasma  very  nearly),  directly  from  the  blood,  has  occurred,  and  be- 
come mixed  with  the  proper  secretion ;  e.  g.  in  ascites  from  pressure 
of  abdominal  tumors,  the  accumulation  is  almost  exclusively  from 
transudation,  and  very  slightly  from  the  natural  secretion. 

The  proper  serous  secretions  are,  therefore,  the  fluids  normally 
found  upon  the  various  serous  membranes,  viz.,  on  the  pleura,  peri- 
toneum, pericardium,  the  cerebral  layer  of  the  arachnoid,  and  the 
membrane  lining  the  ventricles  of  the  brain.  To  these  may  also 
be  added  the  aqueous  humor  of  the  eye,  the  liquor  Cotunnii,  and 
the  endolymph  of  the  internal  ear.  The  liquor  amnii  is  a  serous 
secretion ;  but,  apparently,  to  a  still  greater  extent,  also  a  transuda- 
tion. The  synovial  are  incorrectly  termed  serous  membranes,  and 
their  secretion  is  intermediate  between  the  serous  and  the  mucous 
secretions. 

None  of  the  serous  secretions  contain  histological  elements,  ex- 
cepting fragments  of  the  epithelial  cells  (or  still  perfect  ones)  which 
secreted  them.  Molecular  granules  or  cytoid  corpuscles  are  merely 
accidental  constituents,  when  present. 

In  fact,  the  serous  are  the  simplest  of  all  secretions.  They  ap- 
proximate more  or  less  nearly  to  the  serum  of  the  blood ;  while 
other  secretions  contain  elements  peculiar  to  themselves,  which  they 
have  formed  from  the  blood-plasma.  It  is,  indeed,  for  this  reason 
that  physicists  would  regard  them  as  mere  transudations.     Still, 


TRANSUDATIONS.  181 

they  are  not  identical  in  composition  on  all  the  serous  membranes, 
but  vary  to  suit,  the  requirements  of  each ;  e.  g.  the  fluid  of  the 
ventricles  of  the  brain  contains  the  least  albumen  of  all  (0.5  per 
cent.),  that  of  the  peritoneum  1  per  cent.,  and  that  of  the  pleura  the 
most  of  all  (1.8  per  cent.).  Albumen  is  entirely  wanting  in  the 
aqueous  humor,  and  in  the  liquor  amnii  during  the  last  months  of 
pregnancy.  (Lehmann.)  But  to  the  physiologist  the  idea  that  this 
adaptation  of  the  fluid  to  the  requirements  of  the  surface  is  dele- 
gated to  a  mere  physical  force,  is,  a  priori,  in  the  highest  degree 
improbable,  were  there  no  facts  to  disprove  it. 

It  is  impossible  to  ascertain  the  normal  quantity  of  the  serous 
secretions,  their  amount  is  so  small.  Much  of  the  fluid  found  after 
death  in  the  serous  cavities  is  a  mere  transudation,  doubtless,  occur- 
ring during  the  last  moments  of  life. 

Origin. — From  the  epithelial  cells  of  the  serous  membranes,  as 
already  described. 

Uses. — The  serous  secretions  are  merely  for  the  prevention  of 
friction  of  the  opposed  surfaces  of  the  serous  membranes.  In  the 
eye  and  the  ear  they  evidently  conduce  to  the  perfection  of  the 
senses  of  sight  and  hearing. 

II.  Transudations. 

It  has  been  already  stated  that  mere  transudations  are  very  liable 
to  occur  on  serous  surfaces,  and  these  also  are  very  similar  in  com- 
position to  blood-serum.  Indeed,  the  true  serous  secretions  being 
normally  in  so  small  amount  that  enough  for  analysis  can  hardly 
be  obtained,  the  analyses  of  serous  secretions  (so  called)  are  usually 
those  of  transudations,  mixed  with  a  very  small  amount  of  the 
former.  In  all  cases  when  the  secretion  is  abundant  we  may  as- 
sume that  the  major  part  is  a  transudation  merely.  And,  except  in 
a  few  instances,  transudations  are  to  be  regarded  as  pathological, 
while  the  serous  secretion  is  physiological. 

The  transudations  which  may  be  regarded  as  physiological  are 
the  serous  fluid  in  the  areolae  of  areolar  tissue,  the  halitus  from  the 
lungs,  and  a  certain  amount  of  fluid  also  given  out  on  the  skin,  in- 
dependently of  the  true  perspiration. 

The  pathological  transudations  include  all  cases  of  simple  cedema, 
and  of  dropsy  (ascites,  anasarca,  hydrothorax,  hydrocephalus,  hy- 
drocele, hydrops  articuli,  ovarian  dropsy,  &;c.).  Colliquative  sweats, 
diarrhoeas,  and  the  discharges  in  cholera  must  be  also  referred  to 


182  THE   FLUIDS. 

this  head ;  and  the  hydragogue  effects  (so  called)  of  certain  cathar- 
tics.' 

Transudation  results,  as  a  jyhyskal  necessity^  whenever  bloodvessels 
are  exposed  very  near  to  a  surface  in  contact  with  the  air,  as  is  the 
case  with  the  air-passages  and  the  skin.  But  the  state  of  fulness  of 
the  vessels,  and  the  rapidity  of  the  circulation  through  them,  as 
well  as  the  physical  and  chemical  character  of  the  blood  itself,  also 
exert  a  controlling  influence  on  the  amount  of  fluid  transuded.  The 
fuller  the  vessels,  and  the  slower  the  motion  of  the  blood-current, 
the  greater  is  its  amount.  Hence  congestion  of  the  vessels  of  a 
part  is  a  common  cause  of  transudations ;  e.  g.  diarrhoea  from  portal 
congestion.  And  since  congestion  is  often  produced  by  pressure 
on  venous  trunks,  the  latter  is  commonly  accompanied  by  oedema, 
anasarca,  or  ascites ;  as,  in  case  of  the  last,  from  abdominal  tumors, 
ovarian  or  otherwise.  That  the  accumulation  in  such  cases  is  not 
secretion  merely,  is  evidenced  by  the  fact  that  it  amounts  in  some 
instances  to  2  or  even  3  pounds  per  day. 

Transudations,  like  serous  secretions,  very  nearly  resemble  the 
blood-serum  in  chemical  composition,  and,  like  them,  they  also  nor- 
mally contain  no  fibrine.  But  since  animal  membranes  are  more 
easily  penetrated  by  water  than  by  the  other  constituents  of  the 
blood-serum,  next  by  the  extractive  matter  and  soluble  salts,  and 
then  by  albumen,  it  follows  that  transudations  will  contain  more 
water  proportionally  to  the  solids  than  blood-serum  does,  and  more 
salts  in  proportion  to  their  albumen. 

The  quantity  of  albumen  in  transudations  varies  exceedingly. 
Lehmann  states  that  it  mainly  depends  on  the  following  circum- 
stances : — 

1.  Certain  systems  of  capillaries  transude  more  than  others;  e.g. 
those  of  the  pleura  most  of  all,  and  those  of  the  ventricles  of  the 
brain  least  of  all. 

2.  The  slower  the  blood-current  in  the  capillaries,  the  richer  in 
albumen  is  the  transudation ;  e.  g.  more  albumen  is  found  in  peri- 
toneal transudations  (ascites)  when  dependent  on  pressure  from 
large  tumors  than  when  caused  by  less  disturbance  of  the  circula- 
tion, as  by  cirrhosis  of  the  liver. 

3.  The  poorer  the  blood  is  in  albumen,  the  less  appears  in  transu- 

'  Lehmann  also  adds  hydatids,  and  vesicular  eruptions  on  the  skin  from  any 
cause,  to  this  list. 


TRANSUDATIONS.  183 

dations.  Hence  they  contain  little  albumen  in  Bright's  disease  of 
the  kidney. 

The  salts  in  the  transudations  are  most  abundant  when  the  blood 
is  richer  in  water;  though  they  are  always  less,  proportionally,  than 
in  the  blood-serum,  except  in  some  cases  of  Bright's  disease.  The 
chlorine  and  potassium  compounds  predominate  over  the  other  solu- 
ble salts,  in  the  transudations  as  well  as  in  the  blood-serum.  In  cho- 
lera, or  after  the  administration  of  drastic  purgatives,  the  quantity 
of  salts  is  five  or  even  seven  times  as  great  as  that  of  the  albumen ; 
these  transudations  being,  at  the  same  time,  richer  in  water  than 
any  other  fluid  in  the  organism. 

Fibrine  is  said  by  Lehmann  to  be  present  in  some  morbid  transu- 
dations, and  which  are  termed  fibrinous  transudations  by  Jul.  Vogel. 
We  should,  however,  term  a  fluid  containing  fibrine  in  the  circum- 
stances supposed,  an  exudation^  and  not  a  mere  transudation.  If 
blood-corpuscles  appear  in  a  transudation,  laceration  of  the  minute 
vessels  must  also  have  occurred. 

But  little  of  the  neutral  and  saponifiable  fats  is  found  in  the 
transudations.  The  non-saponifiable  fats  (cholesterine  and  seroline) 
are  far  more  abundant.  The  former,  especially,  is  often  very  abun- 
dant in  the  fluid  of  ovarian  dropsy  and  of  hydrocele.  It  often 
abounds,  also,  in  those  from  the  ventricles  of  the  brain,  and  from 
the  peritoneum  and  pleura. 

Bile-pigment  and  urea  are  also  found  in  transudations ;  and  sugar, 
in  cases  of  diabetes. 

The  quantity  of  the  transuded  fluids  varies  greatly  in  pathological 
conditions,  between  the  least  perceptible  increase  of  the  normal 
transudation  or  secretion  and  the  highest  extremes.  In  a  case  re- 
ported by  the  author,  103  pounds  of  transuded  fluid  were  removed 
from  the  peritoneal  cavity ;  the  patient  (a  female)  being  63  inches 
in  circumference.^ 

Uses. — The  normal  transudation  in  the  areolar  tissue  gives  it  its 
required  fulness  and  suppleness;  while  the  halitus  of  the  lungs  and 
the  transudation  of  the  skin  aid  incidentally  in  preserving  a  moist 
condition  of  the  pulmonary  mucous  membrane  and  the  external 
integument.     The  rest  are  merely  pathological  phenomena. 

'  American  Journal  of  tlie  Medical  Sciences,  Jan.  1856. 


184  THE   FLUIDS, 

III.  Exudations. 

Exudation  has  been  very  often  confounded — and  especially  by 
chemists — with  mere  transudation ;  from  which,  however,  it  is 
widely  diiJerent,  both  histologically  and  physiologically.  Leh- 
mann,  however,  admits  that  while  transudation  is  the  result  of  mere 
physical  agencies,  as  has  been  explained  (p.  182),  exudation  is  due 
to  vital  power.  But  he  limits  exudations  to  inflammation  as  their 
producing  cause,  and  admits  that  their  organizahility  distinguishes 
them  from  mere  transudations. 

We  cannot  restrict  the  idea  of  exudation  to  the  inflammatory 
process  alone,  however.  We  equally  find  organizable  elements 
separated  from  the  blood  in  cases  where  there  is  no  inflammation; 
and  we  cannot  apply  to  such  cases  the  term  transudation,  any  more 
than  we  can  in  case  of  inflammatory  exudations.  Any  organizable 
fluid  spontaneously  separated  from  the  bloodvessels^  ivithout  rupture  of 
their  walls,  is  an  exudation,  whether  it  be  in  the  case  of  repair  (in 
wounds,  &c.)  without  inflammation,  or  m  cases  of  actual  inflam- 
mation. 

Exudations  differ  from  transudations— ^^rs^,  in  regard  to  the  cir- 
cumstances in  which  they  are  formed;  and,  secondly,  in  respect  to 
their  constituents. 

1.  Transudations  are  the  result  of  physical  agencies  merely,  and 
occur  upon  the  natural  free  surfaces  more  especially,  and  while  their 
epithelium  is  still  in  a  normal  state,  and  in  the  areola?  of  the  areolar 
tissue  (p.  181) ;  escaping,  also,  as  Wedl  suggests,  through  the  walls 
of  the  veins.  Exudations  occur  in  consequence  of  some  modified 
action  of  the  vital  force,  and  directly  from  the  capillaries;  and  if 
upon  natural  free  surfaces,  in  consequence  usually  of  inflammation 
or  irritation  of  the  same.  They  also  elevate  and  detach  the  epi- 
thelium, as  is  seen  in  case  of  vesicular  diseases  of  the  skin.  But 
exudations  also  occur — and  not  transudations — upon  free  surfaces 
artificially  produced ;  as  in  case  of  wounds,  with  or  without  loss  of 
substance.  In  all  cases,  indeed,  in  which  repair  takes  place,  or  in 
which  new  formations  (false  membranes,  indurations,  &c.)  are  pro- 
duced, exudations  occur ;  and  it  is  by  their  organization  that  the 
repair  or  the  formation  of  the  new  tissue  is  secured.  Moreover,  in 
normal  nutrition  an  exudation  of  the  plastic  elements  of  the  blood 
occurs  in  the  substance  of  the  tissues,  and  from  which  the  latter  are 
nourished.   But  this  topic  is  included  under  the  subject  of  nutrition; 


EXUDATIONS.  185 

though  the  fact  shows  that  stasis  of  the  blood  is  not  necessary  to 
exudation,  as  some  have  maintained. 

2.  It  follows,  therefore,  that  exudations  differ  from  transudations 
in  their  constituents,  since  the  latter  are  not  organ  izable,  and  there- 
fore cannot  become  the  medium  of  the  reparative  process,  nor  be 
converted  into  adventitious  growths  in  cases  of  inflammation.  In 
exudations  a  considerable  amount  of  fibrine  is  almost  always  pre- 
sent;' an  element  always  wanting,  we  believe,  in  mere  transudations 
(p.  183).  There  is  also  far  more  albumen  in  exudations,  and  the 
phosphates  and  potassium  compounds  are  more  abundant.  Blood- 
corpuscles,  more  or  less  altered,  are  also  often  found  in  fresh  exuda- 
tions ;  but  they  are  not  an  essential  constituent,  and  depend  upon  a 
rupture  of  the  minute  vessels  of  the  part.  Sometimes,  also,  the 
exuded  fluid,  in  case  of  inflammation,  is  stained  by  the  hsematine 
which  has  been  dissolved  out  of  the  blood-corpuscles  stagnant  in 
the  inflamed  part.  Exudations,  indeed,  approximate  more  nearly 
to  the  blood-plasma,  and  transudations  to  the  blood-serum  merely. 
But  the  latter  are  never  precisely  identical  with  the  serum ;  and 
exudations  abound  far  more  in  water  and  in  the  phosphates  than 
does  the  liquor  sanguinis,  while  they  contain  less  fibrine. 

Thus  it  appears  that  no  histological  elements  exist  in  pure  exu- 
dations when  first  separated  from  the  blood,  though  the  former  are 
soon  developed  in  them,  unless  the  exudation  is  promptly  reab- 
sorbed, as  will  appear. 

Origin. — Exudations  are  poured  directly  from  the  bloodvessels 
of  the  part ;  and  as  they  normally  contain  no  blood-corpuscles,  no 
rupture  of  the  vessels  is  required  for  their  effusion,  any  more  than 
in  the  case  of  transudations.  The  exudation  in  an  incised  wound 
is  entirely  free  from  blood-corpuscles,  and  occurs  after  all  hemor- 
rhage ceases.  Exudation  is  not,  therefore,  a  modification  of  secre- 
tion, no  cell  (epithelial  or  otherwise)  nor  other  special  structure 
being  required  for  their  production.  In  inflammatory  exudations, 
blood-corpuscles  are  frequently  also  found,  since  rupture  of  the  ves- 
sels, and  consequent  hemorrhage,  is  a  very  common  concomitant  of 
inflammation.  It  is  in  accordance  with  a  vital  law  of  the  organism 
that  where  new  material  for  repair  is  required^  or  wherever  an  inflam- 
mation occurs,  an  exudation  is  poured  out  from  the  vessels  of  the  part. 

'  Lehmann  states,  however,  that  plastic  exudations  sometimes  occur  without 
fibrine  (vol.  ii.  p.  290).     Non-plastic  exudations  also  contain  it. 


186  THE    FLUIDS. 

Uses. — The  use  of  the  normal  exudations  is  explained  in  the 
preceding  sentence,  since  they  alone  afford  the  materials  for  the 
reparative  process.  Inflammatory  exudations  are,  however,  to  be 
regarded  as  pathological,  and  are  almost  always  productive  of  only 
mischief. 

Varieties  of  Exudations. 

Exudations  differ  much  in  different  circumstances,  in  respect  to 
the  properties  of  their  chemical  constituents ;  but  the  only  varie- 
ties necessary  to  be  mentioned  here  are  the  euplastic,  or  highly 
organizable,  and  the  cacoplastic,  or  imperfectly  organizable.  In- 
flammatory exudations  are  always  cacoplastic ;  and  non-inflamma- 
tory exudations  are  so  also  in  unfavorable  circumstances,  especially 
when  the  blood  is  impoverished.  In  favorable  circumstances,  and 
in  which  exudations  are  required — as  in  incised  wounds — the  latter 
are  euplastic.   Plastic  exudations  contain  more  fat  than  those  not  so. 

Mr.  Paget's  division  into  the  fibrinous  and  the  corjniscular  exuda- 
tions has  reference  to  the  forms  of  organization  occurring  in  them, 
and  which  may  or  may  not  be  due  to  original  differences  in  their 
constituents,  as  will  appear  under  the  next  head.  All  pure  exuda- 
tions at  first  manifest  the  transparency  and  other  physical  properties 
of  the  liquor  sanguinis,  as  has  been  already  stated.  The  physio- 
logical and  histological  differences  between  the  inflammatory  and 
non-inflammatory  exudations,  as  shown  by  their  subsequent  or- 
ganization, will  next  be  explained. 

Changes  occurring  in  Exudations. 

Exudations,  whether  inflammatory  or  not,  generally  become  co- 
agulated soon  after  their  separation  from  the  vessels,  and  then 
promptly  present  the  fibrillated  appearance  already  described.  (Fig. 
49.)  They  may  subsequently  be  (1)  reabsorbed,  or  (2)  may  be  or- 
ganized into  a  new  tissue ;  or  (3)  may  be  converted  into  pus. 

1.  Absorption  of  an  exudation  may  occur  either  before  or  after 
coagulation.  In  almost  all  cases  it  is  desirable  that  infiammatory 
exudations  be  reabsorbed  as  soon  as  possible,  since  only  swelling  of 
the  part  and  other  mischiefs  result  from  their  presence.  The  ex- 
ceptions to  this  proposition  are  very  few,  and  will  be  insisted  upon 
by  those  only  who  still  maintain  the  doctrine — never  sustained  by 
proof  of  any  kind — that  inflammation  and  the  reparative  process 
are  identical.     E.  g.  it  is  never  desirable  that  the  plasma  exuded  in 


EXUDATIONS.  187 

the  cavity  of  the  pleura,  or  the  pericardium,  or  in  the  substance  of 
the  lungs,  or  in  pleuritis,  peritonitis,  or  pneumonitis,  should  remain  ; 
the  sooner  it  is  reabsorbed,  the  better.  In  case  of  non-inflammatory 
exudations,  however,  it  is  usually  desirable  that  they  remain  and 
become  organized  into  new  tissue,  since  they  alone  afford  the  ma- 
terials for  repair.  We  should  receive  the  idea  of  J.  Vogel,  that  a 
coagulated  exudation  is  dissolved,  before  reabsorption,  by  another 
exudation,  called  the  "solvent,"  with  doubt. 

2.  Either  inflammatory  or  non-inflammatory  exudations  may  be- 
come organized;  the  latter  into  tissues  more  nearly  resembling  the 
normal,  since  they,  when  normal  in  composition,  are  euplastic.  In 
case  of  the  inflammatory  exudations  (which  have  been  most  studied), 
coagulation  of  the  fibrine  is  always  the  first  step  towards  organiza- 
tion, the  fibrillation  becoming  more  distinct  than  it  is  in  the  normal 
coagulation  of  healthy  blood;  and  exudation-cells  and  glomeruli 
(Fig.  69)  being  subsequently  developed  among  them,  if  permanent 
new  tissues  are  to  be  formed.  Thus  indurations,  false  membranes, 
&c.,  are  produced  as  sequelae  of  inflammations.  On  the  other  hand, 
euplastic  (non-inflammatory)  exudations  are  organized  into  tissues 
more  nearly  resembling  the  original,  as  in  the  healing  of  wounds 
by  adhesion  or  "first  intention."  This  form  of  organization  is, 
therefore,  to  be  regarded  as  an  ascending  metamorphosis  of  the 
exudation.  It,  however,  when  occurring  on  mucous  membranes, 
proceeds  no  further  than  fibrillation,  and  to  the  subsequent  develop- 
ment of  cells,  perhaps.  The  false  membrane  (so  called)  in  croup 
never  becomes  vascular;  and  therefore,  since  it  has  no  constant 
supply  of  nourishment  from  the  blood,  is  always  spontaneously 
detached  if  the  patient's  life  is  prolonged.  But  in  case  of  inflam- 
mation on  serous  membranes,  well-organized  false  membranes  are 
frequently  found,  as  will  appear.    (Ch.  XI.  Sect.  lY.) 

3.  Both  kinds  of  exudations  are  liable  to  become  converted  into 
corpuscles,  instead  of  fibres,  and  then  into  pus.  Especially  is  this 
the  case  if  they  are  exposed  to  the  action  of  the  atmosphere.  In 
this  case,  exudation-  or  pus-corpuscles  are  usually  developed  in  the 
exudation,  without  any  previous  coagulation;  and  hence  Paget 
terms  it  the  corpuscular,  and  Eokitansky  the  croupous  exudation. 
It  usually  contains  more  fat,  and  the  fluid  part  is  mostly  absorbed 
after  the  corpuscles  are  formed.  The  formation  of  pus  in  an  exu- 
dation is  sometimes  said  to  be  characteristic  of  the  "suppurative 
inflammation."     It  is,  in  fact,  mere  swp'purat'mh — ^.  e.  the  production 


188  THE   FLUIDS. 

of  pus — and  not  inflammation  itself,  nor  necessarily  dependent  on 
inflammation  in  any  sense.  The  corpuscles  first  formed  are  some- 
times called  "exudation-corpuscles,"  as  if  peculiar  to  exudations. 
They  are,  however,  merely  the  cytoid  corpuscles  already  described 
(p.  145),  and  are  developed  in  accordance  with  a  law  stated  on 
page  146.  That  they  are  also  here  histologically  (though  not  phy- 
siologically) identical  with  pus-corpuscles,  will  be  shown  under  the 
characteristics  of  pus. 

Whether  an  inflammatory  exudation  is  to  become  organized  into 
fibres  and  tissues,  or  into  corpuscles  (pus)  merely,  depends  mainly 
upon  three  circumstances  {Paget): — 

1.  The  condition  of  the  blood,  and  therefore  the  composition  of  the 
exudation  itself.  Hence  empyema  is  more  common  as  a  result  of 
pleuritis  in  scrofulous  and  other  debilitated  subjects,  and  adhesions 
in  the  more  robust,  (p.  94.) 

2.  The  seat  of  the  inflammation.  If  this  be  on  serous  membranes 
(as  the  pleura),  fibrillation  and  false  membrane  are  common;  if  the 
tissue  of  the  lung  itself  is  attacked  (pneumonitis),  the  exudation  first 
coagulates  (forming  the  red  hepatization,  as  it  is  improperly  called), 
and  is  then  converted  into  pus,  which,  by  an  equal  misnomer,  is 
termed  the  "gray  hepatization."  In  true  croup,  the  exudation  first 
fibrillates,  and  subsequently,  if  sufficient  time  is  given,  is  developed 
into  pus,  the  fibres  being  previously  dissolved.  Hence,  in  an  abscess 
containing  pus,  fibres  are  also  frequently  found  intermixed,  espe- 
cially in  the  portions  of  pus  first  formed. 

3.  The  intensity  of  the  inflammatory  lorocess  affects  the  organization 
of  the  exudation  by  modifying  its  plasticity.  The  more  intense  the 
former,  the  more  liable  is  the  latter  to  be  developed  into  pus. 

While  the  organization  of  exudations  into  tissues  is  an  ascending 
metamorphosis  of  the  former,  their  conversion  into  pus  must  be  re- 
garded as  an  abortive  attempt  at  the  same.  The  pus-corpuscle  is, 
histologically,  identical  with  the  exudation-corpuscle,  and  not  a  de- 
generation of  the  latter,  as  has  been  asserted.  It  is  merely  an  arrest 
of  development  of  the  exiidation-corpiiscle.  Exudation-corpuscles  nor- 
mally form  cell-walls  around  them,  and  then  develop  the  higher 
tissues;  and  hence  the  exudation  (cytoid)  corpuscles  become,  in  fact, 
the  nuclei  of  exudation-cells,  of  which  less  notice  has  been  taken. 
Hence  Gluge  regards  pus-corpuscles  tis  nuclei,  "because  in  granu- 
lations and  the  formation  of  cicatrices  it  is  readily  and  directly 
conclusive  that  cells  form  upon  pus-corpuscles;  for  the  nuclei  of 
young  cicatrix-cells,  in  appearance  and  chemical  relatious,  are  per- 
fectly identical  with  the  latter."^  We  would  say,  exudation-ceZfe 
form  upon  exudation-corpuscles,  the  latter  being  the  nuclei  of  the 
former;  while  the  pus-corpuscles  are  merely  the  exudation-cor- 
puscles, arrested  in  their  development,  and  destined  not  to  rise  to 

'  Pathological  Histology,  p.  45. 


CHARACTERS   OF   PUS.  189 

any  higher  organization.    Pus  is  totally  aplastic,  and  its  corpuscles 
possess  a  very  low  vitality. 

Origin  and  Characteristics  of  Pus. 

Thus  pus  is  not  a  secretion,  but  is  a  changed  exudation;  the  change 
being  due  to  various  causes,  among  which  the  action  of  the  atmo- 
sphere is  one  of  the  most  prominent.  In  granulating  wounds,  there- 
fore, we  find  a  pure  exudation  constantly  appearing  on  the  surface 
of  the  living  tissues,  with  exudation-corpuscles  and  cells  forming  in 
it;  while  the  external  portion  of  the  exudation  has  become  true  pus. 
All  the  intervening  grades  of  development  between  these  two  ex- 
tremes will,  of  course,  present  themselves.  Flakes  or  fibrillae  of 
coagulated  fibrine  will  also  be  often  found  mixed  with  the  pus  first 
formed  in  an  abscess ;  these  having  been  formed  by  simple  fibril- 
lation as  the  initiatory  step,  and  before  the  pus-corpuscles  are 
developed.  It  is  also  certain  that  pus  may  be  formed  from  a  solid 
mass  of  fibrine  after  its  coagulation.  (Vogel) 

Thus,  also,  it  appears  that  pus  is  formed  from  an  exudation  by  a 
"retrogressive  metamorphosis."  (Wedl.) 

Characters  of  Pus. 

Pus,  when  perfectly  formed — genuine  pus — is  a  yellowish,  creamy, 
thick  fluid,  of  a  specific  gravity  of  1030  to  1033  (Gluge),  and  a  feeble 
alkaline  reaction.  Exposed  to  the  air,  however,  it  soon  undergoes 
transformations ;  passing  into  the  acid  fermentation,  or  the  alkaline, 
or  into  putrefaction.  In  cases  of  phthisis,  pus  is  sometimes  acid 
when  expectorated. 

The  whole  amount  of  solid  constituents  in  pus  is  140  to  160  parts 
in  1,000,  of  which  only  5  to  6  per  cent,  consists  of  mineral  sub- 
stances. Of  the  last,  the  soluble  salts  predominate,  being  propor- 
tioned to  the  insoluble  as  7  or  even  9  to  1.  It  also  contains  the 
oxide  of  iron. 

Seen  under  the  microscope,  pus  consists  of  (1)  a  fluid  portion, 
containing  (2)  histological  elements — the  pus  (cytoid)  corpuscles. 
An  analysis  of  pus,  as  compared  with  that  of  the  blood,  shows  the 
former  to  contain  far  less  albumen,  no  fibrine  at  all,  far  more  fat, 
and  about  three  times  as  much  chloride  of  sodium,  the  latter  being 
confined  almost  exclusively  to  the  pus-serum.  Fibrine,  whether 
coagulated  or  not,  is  sometimes  found  mixed  with  pus,  however ;  a 
portion  of  the  exudation  still  remaining  unchanged.  "  Connective 
tissue-cells"  (nucleated  fibres),  may  also  be  found  in  pus,  from  a 
higher  organization  of  a  part  of  the  exudation.  (Fig.  104.) 

1.  The  jiuid  portion  {pns  serum,  or  liquor  puris)  is  perfectly  clear, 
colorless  or  slightly  yellowish,  has  a  feeble  alkaline  reaction,  and 
coagulates,  on  being  heated,  into  a  dense  white  mass.  Its  main  con- 
stituent is  albumen,  which  constitutes  from  12  to  37  parts  in  1,000. 
Some  of  the  fat  in  pus  also  belongs  to  the  serum,  and  about  1  per 
cent,  of  cholesterine. 


190 


THE   FLUIDS. 


Fig'  104.  Mucosine  {pyine),  and  caseine, 

are  only  abnormal  constitu- 
ents of  pus-serum  {Lehmann\ 
as  are  also  bile-pigment,  resin- 
ous bile  acids,  urea,  and  sugar. 
It  is  the  mucosine  which  forms 
the  filaments  seen  in  Fig.  107. 
It  was  called  pyine  by  Giiter- 
bock. 

2.  Accidentally,  blood-cor- 
puscles, epithelial  cells,  exu- 
dation-cells, and  fragments  of 
tissues  (Fig.105)  may  be  found 
in  pus ;  but  the  only  normal 
histological  element  is  the  cy- 
toid  (pus)  corpuscle,  except 
occasionally  minute  fat-glo- 
bules. 

Pus -corpuscles  (Fig.  106)  have 
already  been  described  under 
the  head  of  cytoid  corpuscles 
(p.  146),  they  being  vesicles 
consisting  of  a  cell-membrane  often  appearing  granular,  with  a  nu- 
cleus adhering  to  it,  and  viscid  hyaline  contents.     They  average 


©  @    @     © 


©    d 


Exudation-cells  and  nucleated  fibres  in  pus.  a. 
Large  granulous  exudation-cells.  h.  Pus-corpus- 
cles, c.  Nucleated  fibres,  d.  Pus-corpuscles,  their 
nuclei  being  brought  out  by  acetic  acid.  a'.  Granu- 
lar exudation-cells  after  action  on  their  nuclei  of 
water. 


Fig.  105. 


Fig.  106. 


Fig.  105.  Other  histological  elements,  in  pus,  in  an  incipient  state  of  fatty  degeneration.  The 
granular  corpuscles  (a)  are  pus-corpuscles ;  the  open  rings  {b)  with  borders  are  red  blood-corpuscles  ; 
the  sharply-defined  circles  are  fat-globules.  Two  epidermic  cells  (c),  with  an  oval  nucleus  are 
also  seen,  and  a  coagulated  mass  with  molecules  (d).    (Wedl.) 

Fig.  106.   Pns-corpnscles.    a.  Natural  appearance,    b.  After  acetic  acid. 

from  3  ^'(,5  to  s^'gg  of  an  inch  in  diameter,  being  usually  larger 
than  the  cytoid  corpuscles  of  the  blood,  and  smaller  than  those  of 
saliva.  They,  however,  vary  in  different  circumstances,  being  all 
small  in  an  abscess,  and  all  large  in  a  wound.  ( Vogel)  They  also 
vary  in  appearance  in  different  states  of  the  organism — as  in  phthi- 
sis, in  typhus,  and  in  the  cancerous  dyscrasia.  {Lehmann)    Besides, 


CHARACTEKS   OF   PUS.  191 

their  size  varies,  on  account  of  their  endosmotic  properties,  with  the 
specific  gravity  of  the  pus-serum,  they  being  contracted  and  smaller 
as  the  latter  increases,  and  vice  versa  (p.  145). 

The  investing  membrane — sometimes  wanting  in  the  smaller  cor- 
puscles (  TFet:?^) — is  an  albuminous  ("proteine")  compound,  but  is  not 
fibrine.  (Lehmann.) 

The  nuclei  of  pus-corpuscles  are  -jg'jg  to  ^g'f^  of  an  inch  in  dia- 
meter ( Weill),  and  also  appear  to  be  an  albuminous  substance.  If 
they  had  been  originally  visible,  they  are  usually  of  a  lenticular 
form,  and  these  are  probably  the  mature  corpuscles.  In  case  they 
are  invisible  at  first,  they  are  subsequently  found  to  be  tripartite, 
and  of  a  sharply- defined  outline.  This  latter  appearance,  usually 
produced  by  a  change  in  the  chemical  reaction  of  the  pus  after  its 
formation,  has  been  thought  to  be  characteristic  of  pus-corpuscles. 
It  has,  however,  been  already  explained  (p.  146). 

The  contents  of  the  pus-corpuscles  are  also  principally  albuminous 
compounds.  {Lehmann.)  The  fat  of  pus  (20  to  60  parts  in  1,000)  is 
contained,  in  great  part  (about  two-thirds),  in  the  corpuscles;  and  the 
granules  are  probably  composed  of  it,  in  part  at  least. 

In  regard  to  the  precise  manner  in  which  pus-corpuscles  are 
formed,  nothing  special  need  be  remarked  here,  they  being  deve- 
loped from  minute  granules  into  larger  corpuscles — the  nuclei — as 
Vogel  has  shown,  and  around  which  the  cell- wall  subsequently  ap- 
pears; it  being  at  first  transparent,  and  afterwards  granular.  They, 
like  all  other  cytoid  corpuscles,  are  first  formed  by  free  cell-develop- 
ment. But  they  may,  doubtless,  be  subsequently  developed  from 
the  pre-existing  corpuscles,  and  thus  pus  propagates  itself  Hence 
the  importance  of  seasonably  evacuating  a  cavity  containing  pus ; 
or  of  destroying  the  pus-corpuscles,  as  by  the  application  of  caustic, 
&c.,  as  in  the  treatment  of  ophthalmia  and  blennorrhoea. 

It  is  a  practically  important  question.  How  long  a  time  is  neces- 
sary for  the  development  of  pus  in  a  fresh  exudation?  Lehmann 
states  that  in  exudations  "not  perfectly  fresh,  obtained  from  subcu- 
taneous wounds  with  loss  of  substance,"  in  the  lower  animals, 
granules  and  nuclei,  constituting  the  beginning  of  the  suppurative 
process,  appear  in  "about  half  an  hour."  Gluge  says  that  in  "twelve 
hours  after  a  blister  is  applied  to  the  surface  of  the  human  body, 
the  exudation  has  become  slightly  turbid  from  the  presence  of  pus- 
corpuscles,  many  of  which  already  have  a  clear  border  to  one-half 
of  their  circumference,  which  is  the  future  cell- wall  in  the  course 
of  development."  The  process  of  development  still  continues,  even 
if  the  exudation  be  removed  from  its  contact  with  the  body.  In- 
deed, in  the  clear  exudation,  when  removed  from  the  surface,  "per- 
fectly spherical  cells  with  nuclei  were  developed  after  several  hours" 
(p.  46).  Helbert  had  before  asserted  that  cells  may  form  in  a  plastic 
liquid  removed  from  the  body. 

In  the  case  of  a  blister,  we  may,  therefore,  conclude  that  true  pus 
may  be  formed  in  less  than  twenty-four  hours.     A  longer  time, 


192 


THE   FLUIDS. 


however,  than  forty-eight  hours  is  required  for  its  development  in 
case  of  wounds ;  and  more  frequently  at  least  seventy-two  to  ninety- 
six  hours  elapse  before  suppuration  is  established  in  case  of  surgical 
operations  in  adults.  It  is,  however,  more  promptly  established  in 
children,  and  in  the  warmer  season  of  the  year. 

Genuine  pus  is  a  bland  fluid,  and  does  not  dissolve  the  tissues  in 
contact  with  it;  but  only  destroys  their  vitality,  if  at  all,  by  pressure. 
It  is  thus  that  the  articular  cartilages  may  die  in  case  of  suppuration 
in  bone  in  contact  with  them.  Morbid  pus,  however  (sanies,  &c.), 
is  highly  corrosive,  and  rapidly  dissolves  the  tissues.  Decomposed 
pus  may  also  produce  the  same  effect. 

It  is  not  necessary  here  to  speak  of  the  pathohgical  conditions  of 
pus,  any  further  than  to  remark  that  the  pus-corpuscles  (like  all 
other  cytoid  corpuscles)  are  liable  to  fatty  degeneration;  strongly- 
defined  fat-globules  appearing  within  them,  as  in  Fig.  105.  The 
serum  also  then  contains  more  fat  than  usual;  and  finally  the  cha- 
racters of  the  pus-corpuscles  are  lost,  only  scattered  molecules  re- 
maining in  their  stead. 

In  connection  with  pus,  Wedl  mentions  a  peculiar  histological 
element,  occurring  most  frequently  and  in  the  greatest  abundance 
in  the  sputa  of  pneumonitis.  It  is  a  finely-granular  globule,  j  g'jj^ 
to  g  Jg^  of  an  inch  in  diameter,  with  a  sharply-defined  cell-wall  of 
a  yellowish  or  yellowish-brown  color,  sometimes  containing  scat- 
tered pigment-granules,  and  entirely  destitute  of  a  nucleus.  Fig. 
107  shows  four  of  these  bodies,  mixed  with  pus-corpuscles  and 


Fig.  107. 

'    ^iiliiii  1/  m 


Granular  globules  (sterile  cells),  without  nuclei,  in  the 
grayisli-ycllow  sputa  of  pneumonitis.  The  smaller  cells 
are  pus-corpuscles,  and  the  lines  represent  filaments  of 
mucosine.  The  sterile  cells  are  filled  with  occasionally 
pigmented  contents.     (Magnified  350  diameters.)  (Wedl.) 


Sputa  of  acute  pneumonitis,  containing 
fibrinous  casts  of  the  minute  bronchial 
tubes,  large  cells  filled  with  oil-globules, 
and  finely-granular  cells  resemblingpus- 
corpuscles. 


filaments  formed  by  the  mucosine  from  the  sputa  above  mentioned. 
They  may  perhaps  be  abortive  glomeruli  or  granule-masses,  and 
hence  Wedl  terms  them  "sterile  cells."     Another  form  of  sputa  in 


USES   OF   PUS.  193 

acute  pneumonitis,  containing  casts  of  tlie  tubes  and  cells  filled  with 
oil-globules,  is  shown  by  Fig.  108. 

Finally,  pus  cannot  be  absorbed  from  a  part  without  disintegra- 
tion of  the  corpuscles,  and  then  reappear  in  another  part,  as  some 
still  maintain.  It  may  enter  the  blood  through  openings  in  the 
vessels  (as  in  stumps,  &c.),  but  in  no  other  way.' 

Uses  of  Pus. 

1.  Puo,  being  a  bland  fluid,  is  incidentally  useful  when  formed  upon 
granulating  surfaces,  in  protecting  the  subjacent  layer  of  the  exuda- 
tion from  the  action  of  the  air,  and  thus  enabling  it  to  be  organized 
into  tissue  instead  of  pus.  The  granulations  themselves  also  would 
be  reabsorbed,  and  the  reparative  process  arrested,  if  the  air  were 
not  thus  kept  from  them.  It  follows,  therefore,  that  whenever  it  is 
impossible  to  exclude  the  air  from  a  granulating  surface  by  artificial 
means,  the  pus  should  not  be  entirely  removed  when  the  dressings 
are  renewed ;  but  only  any  excess,  or  any  portion  which  has  under- 
gone or  may  soon  undergo  decomposition.  Here,  then,  pus  is  inci- 
dentally useful;  though  its  formation — i.e.  supiouration — is  not  de- 
sirable, were  it  possible  to  secure  the  organization  of  the  whole  of 
the  exudation  into  new  tissue. 

2.  Again,  when  an  exudation  has  become  coagulated  in  a  part,  or 
on  a  mucous  membrane,  it  is  sometimes  better  that  it  should  be 
organized  into  pus  than  into  tissue,  provided  it  cannot  be  reab- 
sorbed; for  then  it  may  be  removed  from  the  part.  E.  g.  in  pneu- 
monitis the  exudation  had  better  become  developed  into  pus-cor- 
puscles and  fatty  molecules  (gray  hepatization),  and  be  removed  in 
the  sputa,  than  become  organized  into  an  indurated  mass,  destroying 
the  pulmonary  structure.  And  if  the  exudation  in  true  croup  is 
converted  principally  into  pus  and  removed  by  the  act  of  coughing, 
instead  of  taking  the  form  of  a  tough  false  membrane,  so  much  the 
better  for  the  patient.  In  such  cases,  therefore,  the  formation  of  pus 
is  an  advantage;  in  other  terms,  suppuration  is  an  advantage,  though 
the  pus  itself  is  of  no  use  in  the  orgcinism. 

3.  On  the  other  hand,  suppuration  is  always  directly  destructive  of 
the  exuded  plasma — i.  e.  it  prevents  the  latter  from  being  organized 
into  tissue.  Hence  profuse  suppuration  produces  a  powerful  exhaust- 
ing efi'cct  upon  the  organism,  unless  neutralized  by  an  abundance  of 
nutritious  food.  The  emaciation  which  it  also  produces  is  easily  ex- 
plained by  the  abundance  of  fat  in  pus,  there  being,  on  an  average, 
at  least  ten  to  fifteen  times  as  much,  proportionally,  as  in  the  blood. 
Hence  the  use  of  cod-liver  oil  seems  to  be  indicated  here  as  well  as 
in  scrofula  and  phthisis.     It  also  follows  that  in  all  cases  of  repair 

'  Vogcl  meutions  a  case  of  empj'ema  in  which  a  thick  creamj  fluid  escaped  in 
the  urine  wheu  the  thoracic  efl'usion  subsided.  The  microscope,  however,  showed 
that  the  urinary  admixture  consisted  entirely  of  epithelial  debris. 

13 


194  THE   FLUIDS. 

by  granulation  we  should,  by  excluding  the  air  by  appropriate 
dressings,  and  by  all  other  possible  means,  reduce  the  amount  of 
pus  to  the  minimum. 


The  preceding  is  believed  to  be  the  view  of  the  subject  of  transu- 
dations, exudations,  and  the  formation  of  pus,  which  the  present  state 
of  science  demands.  In  regard  to  the  first  two  subjects,  it  must, 
however,  be  admitted  that  much  still  remains  to  be  ascertained  and 
settled.  Only  well-marked  transudations  on  the  one  hand,  and  exu- 
dations on  the  other,  have  been  here  discussed.  But  all  possible 
transitional  forms  between  the  two  are  found  to  exist ;  there  being 
sometimes  a  transudation  with  a  small  amount  of  exudation  added 
to  it,  and  at  others  precisely  the  reverse.  We  may  also  have  a  trans- 
udation, as  well  as  an  exudation,  mixed  with  pus;  and  herein  lies  the 
essential  difi&culty  in  investigating  these  subjects.  In  conclusion, 
we  must  confess,  therefore,  with  Wedl,  that  "our  present  doctrine 
with  respect  to  exudation  [and  transudation]  is  but  a  very  poor 
crutch,  upon  which  we  must  hobble  for  a  time,  in  order,  in  some 
degree,  to  obtain  a  measure  of  the  field  we  have  to  survey"  (p.  38). 


CHAPTER   III. 

THE   MUCOUS   AND  THE   GLANDULAR  SECRETIONS. 

The  glandular  are  here  associated  with  the  mucous  secretions 
from  the  fact  that  the  ducts  of  all  true  glands  are  lined  by  a  mucous 
membrane,  which  secretes  some  of  the  varieties  of  mucus  in  a  part 
of  its  extent,  while  its  epithelial  cells  in  the  smallest  subdivisions 
of  the  ducts  elaborate  the  secretion  characteristic  of  the  gland.  It 
consequently  results  that  all  the  true  glandular  secretions  contain 
an  admixture  of  mucus,  to  a  greater  or  less  amount;  and  hence  the 
raucous  secretions  will  be  first  described,  under  the  head  of  "Mucus." 

SECTION  I. 

MUCUS. 

It  has  been  supposed  to  be  a  sufficiently  accurate  statement  that 
mucus  is  the  fluid  normally  secreted  upon  the  mucous  membranes. 
While,  however,  we  have  a  definite  idea  of  a  mucous  membrane  as 


MUCUS.  195 

always  containing  the  same  liistological  elements,  it  is  by  no  means 
true  that  precisely  the  same  secretion  is  afforded  by  them  all.  The 
ultimate  ramifications  of  the  ducts  of  all  true  glands  (salivary 
glands,  kidneys,  &c.)  are  lined  by  a  mucous  membrane,  though 
their  secretions  widely  differ  from  each  other,  and  are  in  no  case 
true  mucus.  It  is  more  accurate  to  say  that  the  epithelial  cells 
alone  of  the  membrane  secrete.  But  here  again  we  must  exclude 
the  epithelial  cells  of  the  minutest  gland-ducts  in  specifying  the 
structure  concerned  in  elaborating  mucus. 

Where,  however,  we  find  a  mucous  membrane,  in  other  circum- 
stances, is  expanded  as  a  protective  structure  (as  in  the  alimentary 
canal,  air-passages,  &c.),  we  also  find  minute  cavities  sunk  into  its 
substance  and  opening  upon  its  surface,  and  the  epithelial  cells  of 
these  are  the  actual  secretors  of  true  mucus.  Doubtless,  also,  the 
epithelial  cells  upon  the  general  level  of  the  mucous  membrane 
secrete  mucus,  but  in  a  less  degree.'^ 

Mucus  may  therefore  be  defined  to  be  the  fluid  secreted  by  the 
epithelial  cells  of  the  follicles  and  of  the  general  surface  of  mucous 
membranes,  except  where  they  form  the  lining  of  minute  gland- 
ducts. 

It  is,  however,  not  true  that  mucus  is  always,  in  composition,  the 
same  fluid,  even  when  restricted  to  these  limits.  It  contains  an 
immediate  principle  called  mucosine ;  but  it  has  already  been  stated 
(p.  84)  that  at  least  three  varieties  of  this  substance  exist,  to  which 
as  many  different  forms  of  mucus  correspond.  Indeed,  it  is  clear 
that  the  same  fluid  would  not  answer  the  requirements  on  the  dif- 
ferent mucous  membranes,  or  on  all  parts  of  the  same  one ;  hence 
the  mucus  of  the  mouth  is  very  different  from  that  of  the  nasal 
passages,  and  that  of  the  cervix  uteri  from  that  of  the  uterine  ca- 
vity and  of  the  vagina.  A  more  discriminating  investigation  of 
the  different  fluids  termed  mucus,  because  found  on  mucous  mem- 
branes, is  therefore  demanded.  Physiologically^  mucous  membrane 
has  no  specific  character ^  so  far  as  it  is  secretive,  but  only  so  far  as  it  is 
protective. 

Mucus  is  described  as  a  viscid  mass,  capable  of  being  drawn 
into  threads,  and  consisting  (1)  of  a  pellucid,  cohesive  fluid,  con- 
taining (2)  a  variety  of  morphological  elements,  principally  epi- 
thelial cells. 

'  Synovial  bursce  (so  called)  also  belong  to  tliis  category,  and  secrete  mucus. 


196 


THE   FLUIDS. 


1.  llhe  fluid  portion  alone  of  mucus  is  peculiar,  and  this  alone  is 
to  be  regarded  as  a  secretion.  Its  chemical  reaction  varies ;  being 
alkaline,  for  instance,  in  mucus  from  the  cervix  uteri,  while  it  is 
acid  in  that  from  the  vagina.  It  contains  only  from  4.4  to  11.8  per 
cent,  of  solid  matter,  of  which  0.7  per  cent,  consists  of  salts,  the 
chloride  of  sodium  being  the  most  abundant. 

2.  The  morphological  elements  are  to  be  regarded  as  distinct 
developments,  either  formed  or  merely  inclosed  in  the  fluid  portion. 
The  epithelial  cells  belong  to  the  latter  category;  the  cytoid  (mucus) 
corpuscles  are  developed  in  the  true  mucus,  after  its  secretion  from 
the  blood,  upon  the  mucous  membrane  (p.  147).  The  morphological 
elements,  however,  usually  form  a  large  portion  of  the  whole  mass. 
The  epithelial  cells  are  conoidal  or  otherwise  in  form,  according  to 
the  particular  membrane  or  part  from  which  they  are  derived.  The 
cilia  usually  become  detached  if  the  epithelia  were  ciliated. 

Albumen  does  not  exist  normally  in  mucus,  but  occurs  whenever 
the  mucous  membrane  becomes  inflamed.  {Julius  Vogel.)  It  may 
also  occur  in  mere  congestion ;  but  in  both  of  these  cases  results 
from  transudation.  Fat  is  abundant  in  catarrhal  affections,  in  the 
form  of  vesicles  or  granules ;  there  being,  however,  but  very  little 
in  normal  mucus.  Molecular  granules  are  most  abundant  in  the 
white  sputa  of  typhus.  Coagula  of  fibrine  and  colored  blood-cor- 
puscles are  often  found  on  mucous  membranes  when  inflamed  (e.  g. 

in  croup);  but  here  true  mucus 
is  no  longer  secreted,  but  an 
exudation  has  occurred  instead. 
These  coagula  often  form  tubes 
lining  the  bronchia  in  bronchi- 
tis and  pneumonitis.  A  mixture 
of  mucus  and  blood-corpuscles 
and  epithelial  cells  is  shown  by 
Fig.  109. 

Granular  masses  and  cells — 
inflammation-globules  (p.  119), 
arc  also  found,  especially  in  case 
of  inflammation  of  the  air-pas- 
sages. Some  discover  pus-cor- 
puscles, also,  in  case  of  inflam- 

Muciis-corpuscleB.epitlioIial  colls,  and  blood-disks,      mation     of     tllC     mUCOUS     mCm- 
iu  vaginal  laacus.     Tho  epithelial  colls  arc  rocog-     ,  li."4.1         u  1         A 

nized  by  their  comparatively  very  largo  size.  DranCS  ;     DUt  it  liaS  OeCn  alreaCty 


Fig.  109. 


MUCUS.  197 

shown  that  the  latter  are  not  to  be  distinguished,  in  their  natural 
state,  from  the  normal  cytoid  corpuscles  in  mucus  (p.  146).  Vibri- 
ones  and  microscopic  fungoid  growths  must  be  considered  as  of 
incidental  occurrence. 

It  should  also  be  added  that  a  fluid  possessing  all  the  characters 
ascribed  to  mucus  is  sometimes  secreted  in  certain  cysts. 

The  quantity  secreted  by  the  mucous  membranes  cannot  be  ascer- 
tained with  accuracy.  Valentin  believed  the  amount  to  be  exceed- 
ingly small,  or  even  absolutely  nothing,  in  the  normal  state.  Cer- 
tainly it  is  only  in  irritative  congestion,  or  inflammation,  that  the 
amount  becomes  considerable ;  but  then  there  is  a  transudation  or 
exudation,  or  both,  mixed  with  the  true  mucus. 

Origin. — It  has  been  stated  that  true  mucus  [i.  e.  the  fluid  portion) 
is  secreted  by  the  epithelial  cells  of  the  follicles  or  of  the  general 
surface  of  mucous  membranes,  except  when  they  line  the  ducts  of 
glands;  while  the  epithelial  cells  of  the  latter  secrete  saliva,  urine, 
&c.,  according  to  the  gland  in  which  they  exist.  It  is,  therefore,  the 
epithelial  cells  on  a  mucous  membrane,  and  not  the  mucous  mem- 
brane merely  as  such,  which  manifest  specifi.c  vital  properties  and 
specific  secretory  functions  (p.  195). 

It  has  been  suggested  that  the  true  mucus  is  derived  from  a  sort 
of  decomposition  or  partial  disintegration  of  the  epithelial  cells. 
Though  this  chemical  view  may  be  correct  so  far  as  it  implies  that 
mucus  as  found  is  different  from  the  same  while  still  inclosed  within 
the  epithelial  cells,  there  are  sufficient  physiological  grounds  for  the 
belief  that  mucus  is,  at  any  rate,  originally  elaborated  within  the 
epithelial  cells,  from  the  plasma  of  the  blood.  It  might  be  antici- 
pated that  the  form  of  the  epithelium,  whether  scaly  or  conoidal, 
would  correspond  with  a  difference  in  the  fluid  secreted. 

The  cytoid  (mucus)  corpuscles  are,  by  some,  said  not  to  be  present 
in  normal  mucus.  Kolliker  maintains  that  they  "are  abnormal, 
but  almost  constantly  present,"  in  the  mucus  of  the  oral  cavity; 
being  a  "kind  of  exudation  or  pus-corpuscle,  with  which  they  have 
the  closest  possible  resemblance  in  structure"  (p.  466).  Lehmann 
seems  rather  to  indorse  the  idea  that  the  mucus-corpuscles,  so  called, 
are  merely  abortive  epithelial  cells. 

While  we  agree  with  Kolliker  that  the  cytoid  corpuscles  consti- 
tute no  part  of  the  true  mucus,  we  cannot  regard  them  as  abnormal 
products ;  nor  admit,  on  the  other  hand,  that  they  have  any  deve- 
lopmental relation  to  the  epithelial  cells.     "We  believe  them  to  be 


198  THE   FLUIDS. 

developed  in  the  true  mucus  (probably  from  tbe  mucosine  espe- 
cially), in  accordance  with  the  law  specified  on  page  146.  Hence, 
in  case  of  irritation,  congestion,  or  inflammation  of  the  membrane, 
these  corpuscles  increase;  since  not  only  mucus  is  secreted,  but 
(from  the  consequent  transudation  or  exudation  upon  the  mem- 
brane) albumen  or  fibrine  (or  both)  is  blended  with  it. 

Uses. — True  mucus  is  merely  protective  to  the  parts  with  which 
it  is  brought  in  contact.  Some  of  its  modifications,  however — as 
the  gastric  and  intestinal  fluids — perform  an  important  function  in 
aid  of  digestion,  as  will  appear  (pp.  200  and  201). 

From  the  relations  of  the  mucous  membrane  to  the  true  glands, 
which  have  been  specified,  it  must  follow  that  all  the  glandular 
secretions  must  contain  an  admixture  with  them,  to  a  greater  or 
less  extent,  of  true  mucus  and  mucus-corpuscles. 

Varieties. — Three  varieties  of  mucus  have  already  been  men- 
tioned, viz: — 

1.  The  mucus  from  the  nares  and  bronchial  tubes,  the  large  in- 
testine, and  the  interior  of  the  uterus. 

2.  That  from  the  neck  of  the  uterus.  This  has  an  alkaline  reac- 
tion, while  that  from  the  vagina  is  acid. 

3.  The  mucus  in  the  urine. 

Other  varieties  still  might  be  added,  which  differ  not  only  in 
appearance,  but  also  in  the  characters  of  the  mucosine  they  contain. 

Synovia,  in  its  chemical  composition,  approaches  nearer  to  the 
mucous  than  to  the  serous  secretions.  Tildanus  always  found  mu- 
cosine in  it,  as  well  as  albumen.  The  synovial  bursae  also  contain 
true  mucus  rather  than  synovia,  and  were  by  Bichat  not  iuappro- 
priately  termed  "bursas  mucosae." 

The  remaining  modifications  of  mucus,  which  require  a  particular 
description,  are  the  gastric  and  the  intestinal  fluids. 

The  Gastric  Fluid. 

Pure  gastric  fluid  is  clear,  liquid,  colorless  or  slightly  yellowish, 
of  a  peculiar  feeble  smell,  a  slightly  saltish  taste,  and  of  a  very 
acid  reaction.  It  is  a  little  heavier  than  water,  and  for  a  long  time 
resists  decomposition.  No  morphological  elements  belong  to  it, 
though  the  epithelial  cells  of  the  gastric  follicles  (favuli)  and  their 
nuclei,  and  a  fine  molecular  matter,  are  found  floating  in  it. 

Gastric  fluid,  when  filtered,  contains  only  1.05  to  1.48  per  cent, 
of  solid  elements;  of  which  63  per  cent,  are  organic,  and  37  per 
cent,  are  inorganic  matters. 


THE   GASTRIC   FLUID. 


199 


The  orrjanic  substance  to  which  the  gastric  fluid 
mainly  owes  its  property  in  aid  of  digestion,  is 
called  pepsin.  It  is  closely  allied  to  the  albumi- 
nous compounds. 

The  free  acid  of  the  gastric  juice  is  partly  the 
hydrochloric  and  partly  the  lactic  acid  (p.  61). 
The  former  constitutes,  on  the  average,  0.35  per 
cent.,  and  the  latter  0.45  per  cent,  of  the  fluid. 
The  hydrochloric  acid  usually  does  not  appear 
till  some  time  after  digestion  has  commenced. 
{Lehmann) 

Of  the  mineral  constituents  of  gastric  juice,  the 
chlorine  compounds  are  the  most  abundant.  The 
chlorides  of  sodium,  ammonium,  calcium,  magne- 
sium, and  iron  are  found  in  it. 

Accidentally,  also,  iodide  and  ferrocyanide  of 
potassium,  salts  of  iron,  and  urea  may  exist  in 
gastric  fluid. 

Experiments  lead  to  the  conclusion  that  dogs 
secrete  in  twenty-four  hours  an  amount  of  gastric 
fluid  equal  to  one-tenth  their  weight.  This  would 
give  a  range  between  12  and  18  pounds  for  a 
man.  Lehmann  states,  however,  that,  "according 
to  several  direct  observations  on  a  woman,  as 
much  as  one-fourth  of  the  weight  of  the  body  has 
been  found  to  be  secreted  as  gastric  fluid"^ ! ! !  Of  course  this  is  all 
secreted  directly  from  the  blood,  and  the  latter  is  estimated  by  Leh- 
mann to  constitute  but  one-eighth  of  the 
weight  of  the  body.  No  further  remark 
appears  necessary  upon  his  estimate  of  the 
gastric  fluid. — The  quantity  is  increased  by 
aromatic  substances,  sugar,  alcohol,  and  al- 
kalies. It  is  not  secreted  at  all  duringr 
fasting. 

Origin. — Gastric  fluid  is  secreted  by  the       Gastric  favuu  (aiveoii),  in  the 
epithelial  cells  of  the  peptic  gastric  glands    ^::^':;^'^, 

(Fig.    110),    as    mucus    is   by    the    epithelial      and  l-WOth  of  an  inch  broad  ;  the 
„„Ti       ^n    „,i  1  ,        septa  being  1-1 000th  of  an  inch 

cells  or  other  mucous  membranes,  as  al-    wide. 


Gastric  peptic  glands. 
a.  Common  trunk.  6,  b. 
Its  chief  branches,  c, 
c.  Terminal  coeca,  with 
spheroidal  gland-cells. 


Fig.  111. 


Chemical  Physiology,  p.  168. 


200  THE   FLUIDS. 

read}'  explained.  The  gastric  favuli,  into  whicli  these  glands  open, 
are  shown  by  Fig.  111. 

Function. — It  is  by  the  agency  of  the  gastric  fluid  that  the  albu- 
minous compounds  in  the  food  are  dissolved'  and  converted  into 
uncoagulable  substances,  soluble  in  water  and  dilute  alcohol,  and 
wliich  Lehmann  has  termed  peptones.  Mialhe  first  termed  these 
substances  albuminose  (p.  87).  It  is  probable  that  the  acids  are 
principally  efficient  in  dissolving  these  compounds ;  while  the  pep- 
sin, acting  by  catalysis,  enables  them  to  exert  a  vastly  greater  sol- 
vent power  than  they  would  without  it.  From  3  to  5  grains  of 
coagulated  albumen  may  be  dissolved  in  100  grains  of  recent  gas- 
tric juice.  It  has  no  effect  at  all  on  the  fats  and  other  non-nitro- 
genized  elements  of  the  food,  these  passing  through  the  stomach 
unchanged  by  it.  Other  strong  mineral  acids  (but  not  the  organic) 
may  partially  supply  the  place  of  the  hydrochloric  and  lactic.  Its 
digestive  power  is  also  increased  by  the  addition  of  fat.  Bile  en- 
tirely suspends  its  digestive  power,  and  saliva  diminishes  it. 

The  gastric  fluid,  however,  is  not  sufficient  to  dissolve  all  the 
albuminous  compounds  necessary  to  nourish  an  animal.^  {Lehmann.) 
Besides,  it  loses  its  digestive  power  in  the  duodenum,  where  its  acid 
reaction  is  overcome  by  the  alkaline  bile  and  pancreatic  fluid. 
Another  fluid  must  therefore  flow  into  the  intestine,  below  the 
duodenum,  which  exerts  a  similar  effect,  and  which  will  be  next 
described. 

The  Intestinal  Fluid. 

Frerichs  has  ascertained  that  the  glanduh^  aggregatas  (Peyer's 
patches)  contribute  but  very  slightly^  to  the  formation  of  the  intes- 
tinal fluid — they  being  closed  sacs — and  that  its  true  secreting  or- 
gans are  the  pouch-like  follicles  of  the  small  intestine  (Lieberkuhn's 
follicles),  and  the  similar  larger  and  very  numerous  follicles  of  the 
large  intestine.  In  chemical  composition,  the  fluids  of  the  small 
and  the  large  intestine  are  found  to  be  perfectly  identical. 

The  intestinal  fluid  is  a  glassy,  transparent,  colorless,  tenacious 

'  Bernard  proves  that  while  white  fibrous  tissue  is  dissolved,  muscular  fibre  is 
merely  softened,  as  if  it  had  been  boiled.  Starch,  sugar,  and  fat  are  not  affected 
at  all  by  the  gastric  fluid. 

2  This  assertion  is  doubtless  correct  in  itself,  but  not  at  all  consistent  with  Leh- 
mann's  estimate  of  its  quantity,  mentioned  on  page  199. 

'  Not  in  the  least,  as  will  appear  in  the  chapter  on  "The  Alimentary  Canal." 


THE    INTESTINAL    FLUID. 


201 


mass,  with  a  strong  alkaline  reaction.  (Frerichs.)  Of  course  there 
must  be  more  or  less  true  mucus,  in  all  cases,  in  combination  with 
the  secretion  of  the  follicles.  The  morphological  elements  found 
in  this  fluid  are  conoidal  epithelium-cells  (these  having  secreted  it), 
nuclei  from  the  same  probably,  granular  cells,  and  here  and  there  a 
little  fat. 

This  fluid  averages  3.2  per  cent,  of  solid  constituents,  .195  per 
cent,  being  fat. 

Tlie  quantity  of  the  intestinal  fluid  cannot  be  accurately  ascer- 
tained. Bidder  and  Schmidt  calculate  that  about  9|-  ounces  are 
secreted  in  twenty-four  hours  by  a  man  weighing  140  pounds.  It 
is  secreted  in  greatest  abundance  four  or  five  hours  after  a  meal, 
and  is  increased  by  drinks. 

Origin. — The  intestinal  fluid  is  secreted  by  the  epithelial  cells  of 
the  follicles  of  the  small  and  of  the  large  intestine.  (Fig.  112.) 

Fig.  112. 


Follicles  of  small  intestine,  In  their  rela- 
tions to  the  villi,  showing  their  epithelium 
(partly  diagrammatic).  F,F.  Two  follicles  of 
Lieberkuhn.  6.  Basement  membrane,  c.  Sub- 
mucous tissue,  e.  Conoidal  epithelium,  v. 
Plane  of  the  vessels.  V.  Villus  with,  and  V 
villus  without  epithelium,    n.  Nerve. 


Uses. — This  fluid  is  proved,  by  the  experiments  of  Bidder  and 
Schmidt,  to  unite  in  itself  the  powers  of  both  the  gastric  and  the 
pancreatic  fluids — i.  e.  it  at  the  same  time  digests  flesh  and  all  albu- 
minous substances,  and  also  changes  starch  and  prepares  it  for 
absorption.  It  has  been  seen  that  the  gastric  fluid  loses  its  power 
as  a  digestive  agent  on  arriving  in  the  duodenum ;  and  the  pan- 


202  THE   FLUIDS. 

creatic  fluid  is  reabsorbed,  and  therefore  disappears,  by  tbe  time  it 
reaches  the  middle  of  the  small  intestine.  Other  agencies  are  there- 
fore required  to  complete  the  processes  these  two  fluids  have  com- 
menced, as  the  food  passes  lower  down  the  canal;  and  these  are 
apparently  supplied  by  the  intestinal  fluid  alone.  It  appears, 
moreover,  that  while  bile  suspends  and  the  pancreatic  fluid  impedes 
the  digestion  of  the  albuminous  compounds  by  the  gastric  juice, 
they  do  not  at  all  interfere  with  that  by  the  intestinal  fluid. 

SECTION   II. 
THE   GLANDULAR   SECEETIONS. 

By  the  glandular  secretions  are  meant  those  of  the  true  or  com- 
pound racemose  glands,  and  whose  ducts  are  lined  by  a  prolonga- 
tion from  a  mucous  membrane.  They,  of  course,  all  contain  some 
admixture  of  mucus,  and  will  be  described  in  the  following  order: — 

I.  Milk. 

II,  Semen. 
III.  Glandular  secretions  discharged  into  the  alimentary 

canal  (saliva,  bile,  &c.). 
lY.  Urine. 

V.  The  lachrymal  fluid. 

I.  Milk. 

Human  milk  is  white,  slightly  translucent,  colorless,  of  a  weak 
sweetish  taste,  and  of  an  alkaline  reaction.  Its  specific  gravity  is 
between  1030  and  1034.  After  standing  at  rest  for  a  time,  a  yel- 
low layer  abounding  in  fat  (the  cream)  forms  on  the  surface,  while 
the  fluid  below  becomes  specifically  heavier,  and  of  a  bluish  tinge. 
It  is  not  coagulated  by  boiling,  but  forms  on  its  surface  a  film  of 
coagulated  caseine  mixed  with  fat-globules.  Rennet  (i.  e.  the  mu- 
cous membrane  of  the  calf's  stomach)  coagulates  it,  as  has  already 
been  explained  in  connection  with  the  properties  of  caseine  (p.  88). 
Exposed  to  a  temperature  somewhat  above  the  mean,  an  acid  is 
developed  in  it,  and  which  precipitates  the  caseine,  constituting  the 
acid  fermentation  or  "souring"  of  the  milk. 

The  milk  secreted  for  the  first  three  or  four  days  after  parturition 
has  peculiar  characters,  and  is  called  cohslrum.  This  is  a  turbid, 
yellowish  fluid,  resembling  soap  and  water,  viscid,  and  strongly 
alkaline  in  reaction.  It  contains  more  solid  constituents  than  nor- 
mal milk,  and  passes  more  rapidly  into  the  acid  fermentation.   This 


MILK. 


203 


increase  principally  affects  the  sugar  (to  70  parts  in  1,000)  in  wo- 
man's milk,  and  the  caseine  in  that  of  the  cow.  It  also  contains 
more  fat  than  normal  milk  (even  60  parts  in  1,000),  this  proceeding 
probably  from  the  colostrum- 
corpuscles  ;  and  twice  or  thrice 
the  amount  of  salts. 

Under  the  microscope,  milk 
shows  an  immense  number  of 
fat-globules  suspended  in  a  clear 
fluid,  and  which  are  called  the 
milk-globules.  (Fig.  113.)  For 
a  short  time  after  parturition  it 
also  contains  the  colostrum-cor- 
puscles, some  of  which  are  also 
shown  in  the  accompanying 
figure. 

1.  The  miVc-glohules  are  from 


4T50(J 


to 


5BSg 


(Hassal  says 


_  i__ 

4300 


Milk-globules    and   colostrum-corpuscles,   the 
latter  being  tlie  largest. 


to  4^'^c)  of  an  inch  in  diameter, 

being  fat-globules  surrounded  by  a  special  membrane  of  caseine,  as 

already  stated  (p.  89). 

The  colostrum-corpuscles  (granular  cells)  are  irregular  conglome- 
rations of  fat-granules,  held  together  by  an  amorphous  albuminous 
substance  (homogeneous  substance),  being  ^-qq-^  to  nearly  g^^  of  an 
inch  in  diameter,  having  no  nucleus  nor  cell-wall.  They  occur  not 
only  in  the  colostrum  (up  to  the  third  or  fourth  day  after  partu- 
rition, and  sometimes  even  up  to  the  twentieth),  but  always  also 
when  the  milk-secretion  is  disturbed  by  any  pathological  condition. 
Precisely  similar  bodies  also  occur  in  inflammatory  exudations,  and 
are  then  called  "glomeruli"  and  "inflammation-globules."  (See 
Figs.  42  and  59.) 

Epithelial  cells  often  appear  in  milk ;  cytoid  (mucus)  corpuscles 
rarely — and  in  pathological  states  of  the  mammary  glands.  Fibrin- 
ous clots  and  blood-corpuscles,  of  course,  occur  only  when  hemor- 
rhage into  the  lactiferous  ducts  has  taken  place.  Infusoria  (vibrio 
bacillus  and  byssus),  as  in  the  blue  milk  of  cows,  are  very  rarely- 
observed. 

2.  The  fluid  portion  of  milk  consists,  on  an  average,  of  water 
883.6  parts  {Simon)  to  1,000  of  milk,  holding  in  solution  the  fol- 
lowing substances,  and  in  the  following  proportions : — 


204  THE   FLUIDS. 

Water      .        .         .        .        .         .         .         .     883.6 

1.  Caseine 34.3 

2.  Sugar  of  milk  (lactine)  and  extractive  matters  .       48.2 

8.  Fixed  salts 2.3 

4.  The  butter  (fat)  is  derived  from  tlie  milk-globules,  and 

makes  up  the  remaining  25.3  parts  in  1,000. 

1.  The  amount  o^  caseine  in  woman's  milk  is  greater  after  animal 
than  after  vegetable  food.  It  is,  however,  less  abundant  than  in 
cow's  milk,  the  latter  containing  41.6  [Playfair)  in  1,000.  The 
coagulum  is  also  less  dense,  and  therefore  more  easily  digested  by 
the  infant.  L'Heritier  found  over  50  per  cent,  more  caseine  in  the 
milk  of  the  brunette  than  in  that  of  the  blonde. 

2.  Woman's  milk  contains  more  sugar  than  that  of  the  cow;  the 
latter  containing  34  to  43  in  1,000.  L'Heritier  also  found  that  the 
milk  of  the  brunette  contains  more  sugar  than  that  of  the  blonde, 
in  the  proportion  of  7  to  5.85.  It  is  increased  by  a  vegetable  diet. 
{Dumas  and  Bensch.)  Diseases — especially  syphilis — do  not  appear 
to  modify  its  amount,  nor  does  either  an  abundant  or  an  insuffi- 
cient diet. 

3.  The  salts  are  less  than  one-half  as  abundant  in  woman's  milk 
as  in  that  of  the  cow;  the  latter  containing  5.5  to  8.5  in  1,000.  The 
difference,  however,  more  especially  affects  the  insoluble  salts  be- 
lonffino;  to  the  caseine,  and  which  are  diminished  with  its  diminu- 

DO  ' 

tion.  The  principal  salts  are  the  chlorides  of  sodium  and  potassium, 
and  phosphates  of  the  alkalies,  lime,  and  magnesia,  besides  the  alkali 
combined  with  the  caseine. 

4.  The  fat  (butter)  of  woman's  milk  is  supposed  to  be  richer  in 
oleine  than  that  of  cow's  milk.  It  is  increased  by  fatty  food.  The 
whole  amount  of  fat  is  much  less  tlian  in  cow's  milk  (the  latter 
containing  45  in  1,000),  and  remains  nearly  the  same  through  the 
entire  period  of  lactation.  The  milk  first  drawn  from  the  breasts 
is  poorer  in  fat  than  that  flowing  afterwards.  The  fat  also  dimin- 
ishes in  diseases. 

Albumen  has  been  detected  in  milk  in  case  of  inflammation  of 
the  lacteal  gland.  But  doubtless  mere  congestion  may  cause  it  to 
appear,  a  transudation  being  thus  mixed  with  the  normal  secretion. 
Urea  may  occur  in  the  milk  in  Bright's  disease  of  the  kidney. 
Iodide  of  potassium  may  also  pass  into  the  milk,  but  it  has  not 
been  j^roved  that  cither  medicinal  substances  can. 

The  quantitT/  of  milk  secreted  by  a  healthy  nursing-woman,  from 


MILK.  205 

both  breasts,  in  twenty-four  hours,  averages  about  2  pounds  and  14 
ounces,  or  22  grains  for  every  1,000  grains  of  her  weight.  A  cow 
secretes  only  10.4  grains  to  1,000,  or  13  pounds  and  4  ounces  in 
all.^  {^Lehmann) 

Origin. — Milk  is  secreted  by  the  epithelial  cells  of  tlie  ultimate 
follicles  or  coeca  of  the  lacteal  glands.  It  is  not  to  be,  hence,  in- 
ferred, however,  that  its  constituents  exist  preformed  in  the  blood; 
for  true  secretion  (the  urine  alone,  perhaps,  excepted)  always  implies 
that  the  fluid  secreted  is  formed  in  the  cells  from  the  elements  in 
the  plasma  of  the  blood,  and  therefore  contains  elements  not  to  be 
found  in  the  latter.  It  has  already  been  stated  that  the  sugar  is 
formed  in  the  mammary  gland  (p.  72);  and  the  assertion  of  Mialhe, 
that  caseine  exists  in  the  blood,  though  probable,  has  not  been 
fully  confirmed  (p.  88).  The  caseine  of  the  milk  is  pretty  certainly 
derived  from  the  albumen  in  the  blood. 

The  ducts  and  terminal  follicles  of  the  lacteal  gland  are  shown 
by  Figs.  114  and  115. 

Fig.  114.  Fig.  115. 


Milk-ducts  terminatiug  in  clusters  of  follicles.        Terminal  ca?ca  (follicles)  of  lacteal  gland,  ■n-itli 

their  secreting  cells  (a,  a) ;  nuclei  (b,  h). 

The  epithelial  cells  lining  the  follicles  (Fig.  115)  may  be  seen  to 
contain  the  milk-globules,  and  are  therefore  proved  to  be  the  real 
agents  in  this  secretion.  On  bursting,  they  set  the  globules  free  in 
the  follicles,  which,  communicating  with  the  ducts  (Fig.  114),  pour 
the  milk  into  the  latter. 

Uses. — Milk  is  the  normal  food  of  all  the  mammalia  during  the 
first  period  after  birth.  It  therefore  combines  all  the  elements  ne- 
cessary for  perfect  nutrition  and  rapid  growth.  A  discussion  of  all 
its  important  physiological  relations  would,  however,  be  out  of 
place  here.     The  caseine  is  its  nutritive  element  (p.  89). 

If,  however,  milk  is  the  proper  nourishment  for  the  infant,  while 

'  More  than  double  the  quantity  here  mentioned  by  Lehinauu  is  very  generally 
secreted  by  the  cow,  in  this  country. 


206  THE   FLUIDS. 

growth  and  development  are  rapid,  it  cannot  be  so  for  the  aged. 
Seizures  simulating  apoplexy  are  sometimes  produced  by  milk  in 
aged  persons  not  accustomed  to  its  use. 

Roman's  milk  usually  becomes  suddenly  deficient  in  caseine  at 
the  end  of  a  year  after  parturition.  This  may  be  accepted  as  an 
indication  that  lactation  should  not,  as  a  general  rule,  be  prolonged 
beyond  this  period.  Up  to  this  time  it  becomes  more  and  more 
nutritious,  in  proportion  to  the  increased  size  and  strength  of  the 
infant. 

It  frequently  becomes  necessary  to  substitute  the  milk  of  one  of 
the  lower  animals  for  that  of  woman,  and  the  following  facts  are  of 
interest  on  this  subject: — 

1.  Gold's  milk  contains  a  small  amount  more  of  solid  constituents 
than  woman's  milk,  in  the  proportion  (average)  of  140  to  120  in 
1,000  of  milk.  It  contains  more  caseine  (41.6  :  34.3),  more  fat 
(45  :  25.3),  and  far  more  salts  (7  :  2.3).  On  the  other  hand,  it  con- 
tains less  sugar  (38.5  :  48.2). 

Consequently,  if  from  1,000  parts  of  cow's  milk  nearly  one-half 
(I)  of  the  cream  is  first  removed,  and  then  186  parts  of  water  and 
10  parts  of  sugar  be  added,  the  result  will,  in  composition,  very 
nearly  resemble  woman's  milk,  except  that  the  salts  will  still  be  too 
abundant.  The  following  formula  will,  therefore,  answer,  for  prac- 
tical purposes,  as  nourishment  for  an  infant : — 

R. — Cow's  milk         .         .16  ounces  (1  pint). 
(Remove  one-half  the  cream.) 
"Water        .         .         .3  ounces  (6  tablespoonfuls). 
Sugar         .         .         .       ^  ounce   (a  large  teaspoonful). 

2.  Goat's  milk  is  sometimes  substituted  for  that  of  woman.  It 
contains  132  to  145  of  solid  constituents,  of  which  40.2  to  60.3  are 
caseine,  33.2  to  42.5  are  fat,  and  from  40  to  53  are  sugar,  in  1,000 
parts. 

8.  The  milk  of  the  ass  has  less  (only  91.6  to  95.3)  of  solid  con- 
stituents, there  being  only  16  to  19  of  caseine,  from  12.1  to  12.9 
of  butter,  and  62.9  to  68  of  sugar.  It  is  the  richest  of  all  in  sugar, 
but  poor  in  caseine  and  butter. 

4.  Mare's  milk  contains  162  in  1,000  of  solid  residue,  but  little 
caseine  (17),  a  large  amount  of  fat  (69.5),  and  the  most  sugar  of  all 
(87.5). 

5.  Sheep's  milk  contains  143.8  of  solid  constituents,  40.2  being 
caseine,  42  fat,  50  sugar,  and  6.8  salts. 

A  formula  may  be  easily  deduced  from  the  preceding  data,  if  it 
be  desirable  to  sustain  the  human  infant  on  the  milk  of  either  of 
the  four  animals  last  mentioned. 


SEMEN. 


207 


The  only  carnivorous  animal  whose  milk  has  been  analyzed  is  the 
hitch.  Her  milk  has  an  acid  reaction  (when  she  is  fed  on  animal 
food),  and  contains  274.6  to  224.8  in  1,000  of  solid  constituents.  Of 
these,  80  to  110  are  caseine,  from  68.4  to  109.5  are  butter,  while  the 
quantity  of  sugar  of  milk  is  very  small.  The  last  and  the  butter 
are  increased  by  mixed  food.  The  great  amount  of  caseine  and  of 
fat  deserves  especial  notice,  in  a  physiological  point  of  view. 


II.  Semen. 

Semen,  as  usually  observed,  is  mixed  with  the  prostatic  fluid  and 
that  secreted  by  Cowper's  glands  and  the  vesiculee  seminales.  It 
can  be  obtained  in  its  pure  state  only  from  the  vasa  deferentia  and 
the  testes  of  animals  in  heat.  When  mixed  as  just  stated,  it  is  a 
mucous,  viscid,  colorless  fluid,  considerably  heavier  than  water,  and 
of  a  neutral  or  slightly  alkaline  reaction. 

1.  The  liciuor  seminis,  a  great  part  of  which  is  derived  from  Cow- 
per's glands,  the  prostate,  and  the  vesiculee  seminales,  gelatinizes 
after  emission;  the  gelatinizing  substance  (spermatine)  resembling 
mucus  more  than  fibrine. 

The  salts  most  abundant  in  it  are  the  phosphates  of  lime  and 
magnesia.  The  fat  (p.  78)  exists  principally  in  the  cells  hereafter 
to  be  described.  Yauquelin  found  10  per  cent,  of  solid  constituents 
in  the  semen — viz.,  6  per  cent,  of  organic  matter,  3  of  earthy  phos- 
phates, and  1  of  soda. 

2.  The  peculiar  histologi- 
cal element  of  the  semen, 
the  spermatozoids^  (spermatic 
filaments),  are  the  most  sin- 
gular developments  in  the 
organism.  They  occur  in 
the  semen  of  all  animals, 
and  are  analogous  in  form 
in  all,  though  distinguish- 
able in  each  species,  as  a 
general  rule;  consisting  of 

a    round     oval     or    PVriform  Human  spermatozolds.    A.  From  the  vas  deferens :  1  to 

^.                   ^  •    ^            1              n^  ^'  "^®^''  vfii'iety  of  character ;  5,  seminal  granules.     B. 

OOdy,  to  which    a    long    nia-  From  testis:    1,  large  cell;    2,  same,  containing  three 

ment    or    tail     Sraduallv    ta-  g^'inular   bodies,  from    which    the    spermatozoids    are 

^      ^  developed  ;  3,  a  bundle  of  spermatozoids  still  grouped 

pering  to  a  point,  is  attached,    together.  ^ 


From  s-Trip/xa,  seinon,  (ioov,  animal,  and  e7Joc,  resemblance. 


208  THE    FLUIDS. 

(Fig.  116.)  In  tlie  human  spermatozoid  the  body  is  from  gg'^jg  to 
so'ou  of  an  inch  long,  and  from  175^^  to  ^^'0,5  of  an  inch  in  width, 
and  the  filament  is  from  g^g  to  gj^  of  an  inch  long.  They  were 
formerly  regarded  as  infusorial  animalculte,  on  account  of  their 
active  motions,  the  tail  striking  rapidly  from  side  to  side,  and  pro- 
pelling the  body  in  a  zigzag  direction.  This  motion  may  be  re- 
tained a  long  time  if  the  semen  is  prevented  from  evaporation,  or 
if  placed  in  tepid  serum,  saliva,  or  mucus.  If  double  its  quantity 
of  water  is  added  to  the  semen,  the  power  of  motion  is  lost.  Urine 
very  soon  stops  the  movements.  In  the  interior  of  the  female 
sexual  organs  they  continue  longer  than  elsewhere.  Motion  is  also 
destroyed  by  a  solution  of  opium,  by  alcohol,  by  strychnia,  and  by 
the  electric  spark,  though  not  by  galvanism.  Concentrated  solu- 
tions of  sugar,  albumen,  urea,  and  various  salts  re-excite  the  motions 
again.  If  destroyed  by  strychnia,  the  tail  remains  extended.  The 
spermatozoids  are  not  readily  destroyed  by  putrefaction,  and  may 
be  kept  for  years  as  microscopical  objects,  in  the  dried  state. 

The  seininal  granules  are  also  peculiar  to  semen,  and  within  them 
the  spermatozoids  are  developed.   Hence  they  are  also  called  sperma- 

tophori.  These  are  finely-granular,  pale, 

^^S"  ^^''  sharply-outlined  corpuscles,  from  7  g'go 

^'d^\        to  72*0  0  of  ^'^  inoh  in  diameter.     Fig. 

117   shows   the   development   within 

them  of  the  spermatozoids. 

We  also  find  in   semen   scattered 
epithelial   cells,  cytoid   (mucus)   cor- 
puscles, and  minute  fat-granules;  nei- 
ther of  which  presents  any  peculiarity. 
The  recognition  of  semen  is  often  a 
Phases  of  development  of  spermato-    matter  of  great  mcdico-lcgal  import- 

zoids.     a.  OriRinal  nucleated  cells,     b.  \        •  •  •       i*    „       "n 

17  ,      ,    ,     •  ,      ance.    A  microscopic  examination  will 

The   same   enlarged,  showing  spermato-  1 

zoids.     c.  The  latter  nearly  perfect,  but     at  OUCC  dctCCt  thc  SpCrmatOZoids,  tlicir 

still  inclosed  within  the  cell.  „  .  i  .       .    ,.  tt    ■ 

form  IS  so  characteristic.  Urine  con- 
taining semen  very  readily  becomes  alkaline.  Seminal  spots  (as  on 
linen)  have  been  shown  by  Schmidt  to  differ  from  all  others.  The 
glistening  surface  of  the  spot  will  decide  on  which  side  of  the  linen 
it  is,  and  here  only  can  spermatozoids  be  found.  He  found  that 
seminal  spots  became  of  a  pale  yellow  color  when  kept  near  the 
fire  for  an  hour  or  two,  while  the  form  of  the  spermatozoids  is  not 


SALIVA.  209 

changed.     Other  substances,  treated  in  this  way,  are  colored  green 
(as  vaginal  mucus),  or  arc  not  changed  in  color. 

Origin  and  Uses. — The  spermatozoids  are  developed  within  the 
spermatophori,  as  already  stated,  and  are  the  part  of  the  semen 
indispensable  to  impregnation.  The  spermatophori  are  probably 
developed  from  the  spermatine,  as  cytoid  corpuscles  are  in  plasma, 
as  described  on  page  146.  Their  relation  to  the  seminiferous  tubes 
of  the  testis  will  be  explained  in  the  chapter  on  "  The  Sexual 
Organs." 

III.  Glandular  Secretions  discharged  into  the  Alimentary 

Canal. 

1.  Saliva. 

Saliva,  as  obtained  from  the  oral  cavity,  is  a  mixture  of  the 
secretions  from  the  three  salivary  glands  with  the  mucus  of  the 
mouth.  It  is  a  cloudy,  viscid,  slightly  opalescent  fluid,  without 
taste  or  smell,  and  of  alkaline  reaction.  Its  specific  gravity  varies 
from  1004:  to  1006,  and  its  solid  constituents  from  0.35  to  1  per  cent. 

The  only  histological  elements  in  saliva  are  epithelial  cells  and 
cytoid  (mucus)  corpuscles;  neither  of  which  are,  of  course,  peculiar 
to  it. 

The  pure  saliva  varies  with  the  gland  secreting  it,  whether  the 
parotid,  submaxillary,  or  sublingual. 

The  secretion  of  \h&  parotid  gland  has  a  specific  gravity  of  1006 
to  1008.8,  is  clear  as  water,  and  without  color,  taste,  or  odor;  and 
contains  1.4  to  1.6  per  cent,  of  solid  constituents.  It  contains  much 
chloride  of  sodium  and  of  potassium. 

The  secretion  of  the  submaxillary  gland  resembles  the  preceding, 
but  is  more  viscid,  less  strongly  alkaline,  and  has  a  less  specific 
gravity  (1004)  and  less  solid  residue  (0.855  per  cent.) ;  and  that  of 
the  sublingual  gland  is  the  most  viscid  of  the  three.  All  of  these 
secretions  contain  a  peculiar  organic  substance — salivine^or  ptj-aline 
(p.  88). 

Recent  experiments  give  3  pounds  and  6|-  ounces  (avoirdupois) 
as  the  average  quantity  of  saliva  secreted  by  adults  in  twenty -four 
hours.  [Lehmann)  The  quantity  is  increased  by  the  mastication  of 
dry  and  hard  alimentary  substances,  and  by  movements  of  the  jaw, 
whether  in  chewing,  speaking,  or  singing.  Acid,  aromatic,  and 
pungent  substances  have  the  same  effect. 
14 


210  THE    FLUIDS. 

Iodide  of  potassium  is  always  found  in  saliva  after  the  use  of 
iodine,  and  mercury  enters  it  in  case  of  mercurial  salivation.  It  is 
also  acid  in  certain  abnormal  states,  and  usually  so  during  fasting. 

Origin. — Saliva  is  secreted  by  the  epithelial  cells  of  the  minute 
subdivisions  of  the  ducts  in  the  three  salivary  glands. 

Uses. — The  mechanical  functions  of  saliva  are  fivefold : — 

1.  It  conduces  to  phonation  and  articulation,  by  securing  a  proper 
degree  of  moisture  of  the  tongue  and  oral  cavity. 

2.  It  aids  the  sense  of  taste. 

3.  It  cleanses  the  mucous  membrane  of  the  oral  cavity. 

4.  To  a  certain  extent  it  quenches,  or  rather  prevents,  thirst. 

5.  It  aids  in  mastication  and  deglutition,  and  carries  air  into  the 
stomach,  the  latter  being  inclosed  in  the  form  of  bubbles  during 
mastication.  Bernard  has  shown,  however,  that  it  is  the  parotid 
secretion  which  prevents  thirst,  while  that  of  the  sublingual  is  sub- 
servient to  deglutition,  and  that  of  the  submaxillary  conduces  to 
the  perfection  of  taste. 

An  important  chemical  agency  has  also  been  attributed  to  saliva; 
the  power  of  changing  the  starch  of  the  food  into  sugar.  Bernard 
has,  however,  proved  that  only  mixed  saliva  has  this  efi'ect,  and 
only  when  in  a  state  of  mci^yient  decomposition.  In  fact,  the  influence 
of  saliva  upon  starch  has  been  much  overrated;  the  pancreatic  and 
intestinal  fluids  being  the  principal  agents  for  the  conversion  of  the 
amylacea  into  sugar.  It  normally  only  hydrates  the  starch  after  it 
arrives  in  the  stomach. 

2.  Bile. 

Bile,  as  obtained  from  the  gall-bladder,  is  a  viscid  fluid,  capable 
of  being  drawn  into  threads;  of  a  green  or  brown  color,  a  bitter 
taste,  and  a  peculiar  odor  (often  resembling  musk).  Its  specific 
gravity  is  about  1020,  and  it  is  usually  alkaline,  often  neutral,  and 
very  rarely  acid,  even  in  disease.  When  it  contains  much  mucus, 
it  putrefies  very  readily;  when  nearly  free  from  it,  with  difiiculty, 
or  not  at  all.  It  doubtless  always  contains  some  of  this  element, 
and  to  its  presence  the  viscidity  of  the  bile  is  due.  Pure  bile  has 
not  yet  been  analyzed. 

The  only  morjihological  element  in  bile  is  the  conoidal  epithelial 
cell  of  the  gall-bladder  and  biliary  ducts. 

Bile,  as  usually  obtained  for  examination,  contains,  on  the  average, 
14  per  cent.  (10.2  to  17.3)  of  solid  constituents;  90  per  cent,  of  these 


BILE.  211 

being  organic  matters,  and  10  per  cent,  mineral  substances.     It  be- 
comes more  concentrated  by  a  prolonged  stay  in  the  gall-bladder. 

The  organic  matters  in  bile  are — 1.  The  bile-pigment  (the  brown 
and  the  green)  already  described  (p.  101);  2.  Cholesterine  (see  p. 
75);  and  which,  with  fat  and  fat-acids,  form  27  to  30  per  cent,  of 
the  solid  residue. 

Among  the  mineral  constituents  of  bile,  the  chloride  of  sodium 
preponderates.  There  are  also  found  some  phosphate  and  carbonate 
of  soda,  phosphate  of  lime  and  magnesia,  and  traces  of  iron  and 
magnesium. 

The  amount  of  bile  secreted  in  twenty -four  hours  is  unknown. 
Bidder  and  Schmidt's  experiments  on  the  lower  animals  would  lead 
to  the  conclusion  that  it  is  not  less  than  23  ounces^  in  the  case  of 
an  adult  man  weighing  140  pounds.  It  is  increased  by  animal 
food,  in  quantity,  and  at  the  same  time  in  density. 

Fat,  taken  in  abundance,  increases  it  also.  On  the  other  hand,  it 
is  considerably  diminished  by  the  carbonate  of  soda,  and  by  febrile 
diseases.  Calomel  increases  it;  but  only  so  far  as  the  water  is  con- 
cerned— the  solid  constituents  remaining  the  same. 

The  bile  is  constantly  secreted ;  but  increases  about  three  hours 
after  the  reception  of  food,  and  so  continues  for  some  hours  after- 
wards. After  prolonged  abstinence  it  is  reduced  to  one-fourth  the 
quantity  of  the  secretion  afforded  in  the  twenty-fourth  hour  after 
the  last  meal.  If  an  animal  is  fed  exclusively  on  fat,  no  more  bile 
is  secreted  than  during  fasting.  The  gall-bladder  empties  itself 
in  two  and  a  half  to  three  hours  after  taking  food. 

Origin. — There  can  be  no  doubt  that  the  bile  is  formed  in  the 
liver.^  Not  one  of  its  constituents  exists  preformed  in  the  blood  of 
the  portal  vein ;  and  icterus  does  not  occur  in  any  disease  which 
attacks  the  parenchyma  of  the  liver,  and  thus  entirely  suppresses 
the  secretion  of  bile.  The  epithelial  cells  lining  the  terminal  sub- 
divisions of  the  hepatic  ducts  are  the  immediate  agents  of  the 
biliary  secretion.  Fig.  118  shows  Kolliker's  idea  of  the  relations 
of  these  cells  to  the  "parenchymal  cells"  of  the  liver  itself;  the 
ducts  directly  abutting  upon  the  latter,  as  he  believes;  and  Fig, 
119,  the  secreting  cells  when  isolated.     The  actual  structure  is, 

'  Todd  and  Bowman  estimate  the  quantity  at  54  ounces,  containing  2  ounces  of 
solid  constituents  (pt.  iv.  p.  480). 

^  Except,  perhaps,  the  pigment,     (See  p,  101.) 


212 


THE    FLUIDS. 


however,  shown  by  Fig.  370,  and  explained  in  the  section  upon 
the  liver. 


Fiff.  118. 


Fig.  119. 


Diagram  of  the  arrangement  of  the  cellular  parenchyma 
{bb)  of  the  human  liver,  with  reference  to  the  radicals  of 
the  interlobular  ducts  (ad),  and  the  vascular  spaces  (c  c). 


Isolated  cells  of  the  liver.  a. 
Nucleus.  6.  Nucleolus,  c.  Oil-parti- 
cles. 

The  suga)'  formed  by  the 
liver  is  not  an  element  of 
the  bile  (p.  70).  It  is  found 
in  the  "parenchyma"  of 
the  liver,  and  is  greatly 
increased  in  diabetes. 

Function. — Several  dis- 
tinct functions  have  been 


ascribed  to  the  bile: — 

1.  It  neutralizes  the  acids  of  the  gastric  fluid,  when  the  contents 
•of  the  stomach  enter  the  duodenum.  The  latter  always  react  acid ; 
but  it  is  to  the  quickly  decomposing  acids  of  the  bile  that  the  acidity 
is  due.  It  also  precipitates  the  substances  dissolved  by  the  gastric 
fluid,  and  hardens  those  softened  by  it.  {Bernard.) 

2.  It  prevents  the  putrefactive  decomposition  of  the  contents  of 
the  intestine;  holding  them,  as  it  were,  in  statu  quo  till  the  pan- 
creatic fluid  exerts  its  peculiar  action  upon  them. 

3.  The  power  attributed  to  bile  in  dissolving  fat  has  been  over- 
rated ;  though  it  cannot  be  wholly  denied.  It  is  a  well  known  fact 
that  bile  removes  greasy  stains;  and  it  has  been  shown  that  fat 
passes  much  more  easily  through  membranes  saturated  with  bile 
than  through  those  moistened  with  water.  It  is  also  found  that 
2 1  times  less  fat  is  absorbed  from  the  intestine  when  the  access  of 
bile  is  prevented.  The  influence  of  bile,  therefore,  in  aid.  of  the 
absorption  of  fat  is  undoubted. 

4.  Finally,  bile  aids  in  securing  a  regularity  of  defecation,  from 
its  stimulating  effects  upon  the  muscular  coat  of  the  alimentary  canal. 

Pathological  States  of  the  Bile. 

Alhumen  is  found  in  the  bile  in  the  embryonic  state,  some- 
times in  fatty  liver,  in  Bright's  disease,  and  in  cases  of  abscess  of 


PANCREATIC   FLUID.  213 

the  liver.  The  albumen  is,  in  these  last  cases,  probably  due  to 
transudation. 

Urea  occurs  in  the  bile  in  uraemia,  and  therefore  principally  in 
cholera  and  Bright's  disease. 

The  solid  constituents  are  usually  increased  in  the  bile  in  cases 
of  cardiac  affections  and  abdominal  diseases  which  produce  con- 
gestion in  the  large  veins;  and  in  cholera,  in  which  disease  all  the 
fluids  become  more  dense  from  the  loss  of  water. 

On  the  other  hand,  the  bile  is  more  icatery  after  violent  inflam- 
mations, in  dropsical  affections,  typhus,  tuberculosis,  and  diabetes. 
In  these  conditions  the  amount  of  water  in  the  bile  seems  always 
to  be  in  a  certain  proportion  to  that  in  the  blood. 

'^\\\2iVj  concretions  (chololithi)  are  of  three  kinds:  1.  Of  choles- 
terine,  inclosing  a  nucleus  of  pigment;  2.  Of  the  chalky  pigment 
alone;  3.  Of  pigment  with  lime;  of  a  dark  green  or  black  color, 
and  almost  free  from  cholesterine. 

The  regurgitation  of  bile  into  the  stomach  at  once  arrests  the 
action  of  the  gastric  juice  (p.  200). 

3.  The  Pancreatic  Fluid. 

This  secretion  is  colorless,  clear,  slightly  viscid,  tasteless,  and 
odorless,  and  presents  a  tolerably  strong  alkaline  reaction.  It  co- 
agulates on  being  heated.  Its  specific  gravity  is  variable ;  the  con- 
centration standing  in  inverse  ratio  to  the  quantity  of  secretion 
afforded  in  a  given  time. 

The  pancreatic  fluid  transforms  starch  into  sugar  in  a  few  mi- 
nutes, and  decomposes  the  neutral  fats  into  glycerine  and  the  cor- 
responding fat-acids. 

About  seventy-eight  per  cent,  of  the  solid  residue  of  this  fluid  is 
the  organic  substance  peculiar  to  it — pancreatine  (p.  83). 

The  mineral  constituents  of  this  fluid  are,  principally,  chloride 
of  sodium,  phosphates  of  the  alkalies  and  earths,  sulphates  of  the 
alkalies,  and  carbonate  of  lime. 

The  quantity  of  the  pancreatic  fluid  is  not  accuratel}^  known. 
Experiments  indicate  that  it  varies  not  far  from  4:f  ounces  in  twenty- 
four  hours  in  an  adult  man.  [Bidder  and  Schmidt)  It  is  independ- 
ent of  the  volume  of  the  pancreas,  and  attains  its  height  during 
the  period  of  digestion.  Ingestion  of  solid  food,  and  also  especially 
of  drinks,  augments  it. 

Orirjin. — The  pancreatic  fluid  is  secreted  by  the  epithelial  cells  of 
the  ultimate  subdivision  of  the  duct  of  ( Wirsung\  the  pancreas. 

Function. — The  pancreatic  fluid  changes  starch  into  glucose,  the 
albuminous  elements  of  the  food  into  albuminose,  and  the  fatty  into 


214 


THE    FLUIDS. 


an  emulsion  {Bernard) ;  the  last  being  absorbed  partly  by  the  lac- 
teals  and  partly  by  the  bloodvessels  of  the  villi,  and  the  first  two 
by  these  vessels  alone.  It  cannot,  however,  be  the  main  agent  in 
changing  the  fatty  elements  below  the  jejunum;  since  it  is  changed 
or  reabsorbed  before  it  reaches  the  middle  of  the  small  intestine. 
The  intestinal  fluid  supplies  its  place  in  this  respect,  through  the 
remaining  portions  of  the  alimentary  canal  (p.  201). 


Fig.  120. 


Mucus-corpuscles  and  epithelial 
cells  in  urine. 


lY.  Ueine. 
The  urine  is  of  a  lighter  or  deeper  amber  color,  and  has  a  bitter 
saline  taste;  being,  while  still  of  the  temperature  of  the  body,  per- 
fectly clear  and  transparent,  and  of  a  pe- 
culiar faintly  aromatic  odor,  and  acid  re- 
action. Its  specific  gravity  never,  in  the 
normal  state,  rises  above  1030  [Lelimann)^ 
and  averages  not  more  than  1020. 

The  only  mojyhological  elements  nor- 
mally found  in  urine  are  epithelial  cellsj 
and  more  or  less  cytoid  (mucus)  corpus- 
cles (Fig.  120);  these  being  accidentally 
present,  as  they  are  in  the  other  glandu- 
lar secretions,  and  presenting  nothing 
peculiar. 

But  in  pathological  conditions,  a  variety  of  histological  elements 
may  be  found.  Of  these,  the  spermatozoids,  pus-  (cytoid)  corpus- 
cles, blood-corpuscles,  and  fibrinous  casts  of  the  tubuli  uriniferi,  are 
the  most  common;  to  which  may  be  added  cells  and  fibrinous  casts 
containing  fat-globules,  as  occurring  in  Bright's  disease;  and  the 
large  and  small  organic  globules. 

1.  Siiermato^Mids  (Fig.  116)  are  found  most  abundantly  in  the 
urine  after  pollutions  and  sexual  inter- 
course, and  are  not  to  be  referred  to  a 
patliological  state  except  in  some  cases 
of  spermatorrhoea. 

2.  Pm.9  occurs  in  urine  (Fig.  121)  in 
cases  of  inflammation  of  the  bladder; 
but  the  pus-corpuscle  not  being  distin- 
guishable histologically  from  the  mucus 
corpuscles  (p.  14(3),  needs  not  a  distinct 
notice  here.  Cytoid-corpuscles  abound  in  the  urine  in  case  also  of 
inflammation  of  the  kidney  and  the  prostate;  and  in  vesical  catarrh, 
so  called. 

3.  Blood- corpuscles  appear  in  inflammation  of  the  kidney,  &c.;  in 
consequence  of  hemorrhage  from  any  part  of  the  urinary  passages. 


Fig.  121. 


I'us-coriiuselcs  in  urirn 


URINE. 


215 


Their  form  is  changed  by  the  action  of  the  fluid  in  which  they  are 
found,  they  most  frequently  resembling  transparent  rings.  (Fig.  122.) 

4.  The  casts  of  the  tubuli  uriniferi  are  bot- 
tle-shaped or  cylindrical  in  form,  and  resem- 
ble fine  hairs.     They  are  from  less  than  j  J^ 


Fig.  122. 


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% 


«^ 


to  g'(j  inch  long,  and  j^'^^  inch  in  diameter;  'q. 
and  present  three  varieties:  1.  Those  consist- 
ing  of  the  epithelial  coat  alone  of  the  urini- 
ferous  tubes.  These  are  observed  in  the  com- 
mencement of  Bright's  disease,  and  in  the 
desquamative  stage  of  erysipelas  and  scarla- 
tina. 2.  Those  consisting  of  recent  exuda- 
tion; generally  granular,  and  containing  more 
or  less  blood  and  pus-corpuscles.  3.  Those 
consisting  of  pure  coagulated  fibrin;  resem- 
bling hyaline  tubes,  and  often  hard  to  recognize  on  account  of 
their  transparency.' 

5.  Fibrinous  casts  and  cells,  containing  fat-globules,  are  found  in 
Bright's  disease.  Figs.  123,  124,  and  379  represent  these  casts  and 
cells. 


Colored    blood-corpascles    in 


Fig.  123. 


Fig.  124. 


Fibrinous  cast  of  uriniferous  tube. 


Fibrinous  cast  containing  epithelium  and  fat-globules. 
a.  Cells  containing  fat  drops.    6.  A  fibrinous  cast. 


6.  The  large  organic  globules  (Fig.  125),  are  not  unfrequently  met 
with  in  the  urine  of  pregnant  women.     They  appear  to  be  merely 


Fig.  125. 


Fig.  126. 


O 

O 

oo 

o 

0 

0 

o    o 

0 

o 

o 

o 

c 

c 

o 

o 

O     1 

Small 

organic  globule:. 

Large  organic  globules  (400  diameters). 

'  Dr.  J.  H.  Bennet  adds,  the  "  waxy  casts" — tlie  detached  basement-membrane 
alone  of  the  tubes. 


216 


THE   FLUIDS. 


a  larger  kind  of  cytoid  corpuscle  than  those  of  mucus  or  pus. 
They  are,  moreover,  not  attended  by  the  viscid  and  the  albuminous 
fluid  which  respectively  characterize  mucus  and  pus.  {J.  E.  Boio 
man) 

The  small  organic  globules  (Fig.  126)  are  far  more  rarely  found. 
They  are  spherical,  smooth  externally,  and  not  granular  within; 
are  unaffected  by  acetic  acid,  and  are  much  smaller  than  the  pre- 
ceding. 

To  these  histological  elements  maybe  added  a  thread-like /wn^'ws 
(confervoid),  called  the  torula.  (Fig.  127.)  These  threads  are  made 
up  of  cells  gg'gxj  to  ggJgTj  of  ^^  inch  in  diameter.  It  occurs  in  de- 
composed urine,  whether,  as  in  vesical  catarrh,  decomposition  corn- 


Fig.  127. 


Fig.  128. 


The  toi'ula  in  urine ;  crystals  of  uric  acid 
and  two  epithelial  cells. 


Fungoid  growths  in  the  urine. 


mences  in  the  bladder,  or  after  its  emission.  Another  kind  of  fun- 
goid vegetation  occurring  in  urine  is  seen  in  Fig.  128,  in  connection 
with  crystals  of  oxalate  of  lime. 

Vihriones  and  monads  also  appear  in  decomposed  urine ;  and  the 

Fig.  129. 


Sarcina  ventriculi. 


sarcina  ventriculi  of  Goodsir  has  frequently  been  found  in  it.  (Fig. 
129.) 


URINE. 


217 


In  chemical  comjMsition  1000  parts  of  urine  consist  of  933  to  972 
parts  of  water,  holding  67  to  28  parts  of  solid  matters  in  solution. 
The  following  analyses  by  Lehmann  and  Becquerel,  present  the 
proportions  of  each  element : — 


Lehmann. 

Water       .        .        .  937.682 

(Solid  constituents  62.318) 

Urea          .         .         .  31.450 

Uric  acid  .         .         .  1.021 

Lactic  acid         .         .  1.496 

Extractive  matters     .  10.680 

Lactates     .         .         .  1.897 
Chlorides  of  sodium 

and  ammonium      .  3.646 

Alkaline  sulphates     .  7.314 

Phosphate  of  soda     .  3.765 
Phosphates   of  lime 

and  magnesia         .  1.132 

Mucus       .         .        .  0.112 


Becquerel. 

971.935 


(28.066) 


Other  organic 
matters 

f  Chlorine     . 


Sulphuric  acid  . 
Phosphoric  acid 
Potash 

Soda,  lime,  and 
magnesia 


12.102 

0.398 

8.647 

0.502 

0.855 
0.317 
1.300 

3.944 


It  will  be  noticed  that  Lehmann  found  nearly  twice  the  amount 
of  solids  obtained  by  Becquerel,  and  about  2J  times  as  much  urea 
and  uric  acid.  Berzelius  and  Marchand  agree  in  all  these  respects 
very  nearly  with  the  former,  and  Simon  and  Dr.  Miller  with  the 
latter.  Of  course  the  composition  of  the  urine  varies  with  its  spe- 
cific gravity,  and  to  this  fact  the  disparity  is  doubtless  due.  Dr. 
Christison  constructed  a  table  showing  the  amount  of  solid  con- 
stituents in  urine  of  different  specific  gravities,  which  proves  that 
the  former  increase  very  rapidly  with  slight  increments  of  the 
latter.  S.  g.  with  a  specific  gravity  of  1012,  the  solids  are  27.96 
in  1,000 ;  while,  if  the  former  be  increased  to  1030,  the  latter  are 
69.90.  If  we  look  at  the  urea  alone,  we  also  find  a  rapid  aug- 
mentation as  the  specific  gravity  increases.  If  the  specific  gravity 
is  1013.5,  only  15  parts  in  1,000  are  urea;  while,  if  the  former  be 
1027,  there  will  be  37.5  of  urea — or  just  2\  times  as  much.  {Leh- 
mann) To  reconcile  the  analyses  of  Lehmann  and  Becquerel,  we 
have  therefore  only  to  suppose  that,  while  the  specific  weight  in  the 
latter  was  actually  1017.01,  in  the  former  it  must  have  been  at  least 
1025.   But  the  results  obtained  by  Becquerel  are  the  more  valuable 


218  THE   FLUIDS, 

in  practice,  since  the  specific  gravity  averages  not  more  than  1020, 
and  is  generally  rather  less  than  this,  according  to  most  writers. 

Of  all  the  constituents  in  solution  in  the  urine,  urea  is  the  most 
important.  Its  proportional  as  well  as  its  absolute  amount  varies 
extremely,  the  kind  of  food  having  a  great  influence  in  this  respect 
(p.  69).  An  increased  secretion  of  water  is  also  accompanied  by 
an  increased  amount  of  urea,  in  the  twenty-four  hours.  E.  g.  if 
1,000  grains  of  urine  be  secreted  in  twenty-four  hours,  33  grains 
are  urea;  if  2,000  grains,  about  42  grains  of  urea;  and  if  3,000 
grains  of  urine,  about  50  of  urea.  Of  course  the  specific  gravity 
will  be  lowest  in  the  last  case,  so  that  the  amount  of  urea  in  one 
thousand  parts  of  urine  will  be  least  of  all.  It  has  been  seen  that 
the  urea  is  derived  directly  from  the  nitrogenized  elements  of  the 
food  and  of  the  decomposed  tissues  (p.  69). 

Of  uric  acid^  from  7.7  to  13.9  grains  are  excreted  in  the  urine, 
by  an  adult,  in  twenty-four  hours.  Its  amount  depends  less  on  the 
kind  of  food  taken  than  on  the  internal  conditions  of  the  organism 
(p.  64). 

Creatine  and  creatinine  (pp.  67,  68)  are  normal  constituents  of  the 
urine,  but  their  amount  has  not  been  determined. 

Formic  acid  is  sometimes  found  in  healthy  urine,  in  very  small 
quantities.     Hippuric  acid  is  hardly  more  abundant  than  the  uric. 

Lactic  acid  is  not  found  in  normal  urine,  but  at  once  occurs  in 
those  states  of  the  organism  in  which  the  process  of  oxidation  is 
interfered  with  (pp.  60,  ^Q). 

The  chlorides  of  sodium  and  potassium  are  very  abundant  in 
urine.  An  adult  secretes  about  162  grains  of  chlorine  in  twenty- 
four  hours.  They  greatly  diminish,  or  even  entirely  disappear,  in 
diseases  accompanied  by  copious  exudations — as  in  acute  dropsy, 
acute  Bright's  disease,  acute  tuberculosis,  in  violent  diarrhoeas,  cho- 
lera, typhus,  and  pneumonitis. 

The  sulphates  are  found  in  variable  quantities.  An  adult  ave- 
rages 31.4  grains  of  sulphuric  acid  in  twenty-four  hours.  They 
are  increased  only  by  violent  bodily  exercise  (as  in  convulsions  and 
delirium  tremens),  and  in  high  mental  excitement. 

The  acid  phosphate  of  soda  (p.  57)  is  the  principal  source  of  the 
acid  reaction  of  the  urine.  The  phosphates  of  lime  and  magnesia 
are  also  found  in  considerable  amount,  and  in  the  proportion,  on  an 
average,  of  15  to  7.  An  adult  discharges,  on  an  average,  49.4  to 
80.2  grains  of  phosphoric  acid  in  twenty-four  hours,  and  15.4  grains 


URINE.  219 

of  earthy  phosphates.  The  phosphates  increase  after  taking  nitro- 
genized  food,  and  in  acute  affections  of  the  nervous  substance — e.cj. 
in  encephalitis  (p.  49). 

It  sometimes  occurs,  in  the  last  months  of  pregnancy,  that  no 
lime  at  all  is  secreted  in  the  urine;  there  being  little  or  none  in  the 
blood  also,  as  will  be  shown  (Chap.  VII). 

Traces  of  iron  and  silicic  acid  are  usually  found  in  urine ;  and 
gases  are  also  dissolved  in  it,  especially  carbonic  acid  and  a  little 
nitrogen. 

Some  substances — alimentary  or  medicinal — pass  unaltered  into 
the  urine.  These  are  such  as  are  easily  soluble  in  water,  and  do 
not  form  insoluble  compounds  with  the  constituents  of  the  body; 
and  which  are,  moreover,  not  readily  oxidizable  or  decomposable. 
Thus  the  nitrates,  carbonates,  chlorates,  borates,  and  silicates  of  the 
alkalies,  and  the  chlorides,  bromides,  and  iodides  of  potassium  and 
sodium,  pass  unaltered  into  the  urine ;  while  sulphuret  of  potassium 
is  oxidized,  and  appears  in  the  urine  as  sulphate  of  potassa.  All 
the  salts  of  the  metals  pass  into  the  urine  unchanged,  only  when 
taken  in  large  quantities;  since  they  form  insoluble  compounds 
with  animal  matters,  especially  with  albumen.  Mannite,  quinine, 
&c.,  are  fully  oxidized  into  carbonic  acid  and  water.  Most  of  the 
organic  acids,  as  well  as  sulphocyanide  and  ferrocyanide  of  potas- 
sium, reappear  in  the  urine  unchanged.  Tannic  acid  is,  however, 
converted  into  gallic,  benzoic  and  cinnamic  into  hippuric,  uric  acid 
into  urea,  and  oxalic  acid  into  carbonic  acid  and  water.  The  neu- 
tral salts  of  the  alkalies,  with  the  vegetable  acids,  reappear  in  the 
urine  as  carbonates;  and  hence  the  urine  speedily  becomes  alkaline 
after  their  reception.  Urea  passes  unchanged  into  the  urine.  Co- 
loring or  odoriferous  matters  generally  pass  unchanged  or  slightly 
modified.  The  following,  however,  do  not  reappear,  viz  :  camphor, 
resin,  inflammable  oil,  musk,  alcohol,  ether,  cochineal,  litmus,  chlo- 
rophyl,  and  the  coloring  principle  of  alkanet. 

The  rapidity  with  which  different  substances  appear  in  the  urine 
varies  much.  Iodide  of  potassium  often  appears  after  four  to  ten 
minutes. 

The  following  ahnormal  constituents  may  appear  in  the  urine  in 
pathological  conditions,  viz:  albumen,  fibriue,  caseine(?),  fat,  sugar, 
abnormal  pigments,  biliary  acids,  bile-pigment,  xanthine,  cystine, 
carbonate  of  ammonia,  sulphuretted  liydrogen,  butyric  acid,  and 
ammoniacal  salts. 


220  THE    FLUIDS. 

Sugar  is,  however,  normally  present  in  the  urine  during  preg- 
nancy, and  of  nursing  women ;  always  in  the  latter,  and  in  one-half 
the  cases  of  the  former.  Its  amount  varies  from  1  to  12  grains  in 
1,000  of  urine;  it  being  more  abundant  as  the  milk  is  more 
abundant  and  rich.  {M.  Blot.) 

Albumen  may  appear  in  the  urine  in  any  case  in  which  there  is 
congestion  of  the  kidney,  or  a  too  watery  condition  of  the  blood ; 
its  presence  being  due,  doubtless,  to  a  mere  transudation,  and  not  to 
a  modified  action  of  the  secreting  cells.  Hence  albuminuria  is  by 
no  means  peculiar  to  Bright's  disease,  but  occurs  also  in  the  course 
of  fevers,  in  renal  catarrh,  in  cases  of  disease  of  the  heart  or  lungs, 
or  tumors  of  the  abdomen,  and  frequently  in  dropsy.  Fat  appears 
in  the  urine  after  taking  fatty  food,  though  rarely.  Isolated  fat- 
globules  are  sometimes  seen  in  cases  of  rapid  emaciation ;  also, 
either  free  or  in  the  tubular  casts,  in  Bright's  disease.  Ammoyiia 
salts  are  found  in  the  acid,  and  especially  in  the  alkaline  fermentation 
of  the  urine.  In  acid  pathological  urine  the  occurrence  of  ammonia 
is  not  unusual — as  in  typhus,  measles,  and  scarlatina.  Ammonia  is 
almost  always  contained  in  alkaline  urine ;  for  the  alkaline  reaction 
depends  either  primarily  on  ammonia  formed  by  the  decomposition 
of  urea  (especially  in  vesical  catarrh),  or  upon  carbonates  of  the 
alkalies,  which  soon  decompose  the  urea. 

The  quantity  of  urine  secreted  in  twenty-four  hours  varies  ex- 
tremely, the  two  most  important  factors  bearing  on  it  being  the 
mechanical  conditions  for  the  passage  of  urine  through  the  kidneys, 
and  the  condition  of  the  blood,  {Lehmann.)  An  adult  male  excretes 
from  17|  ounces  to  112|  ounces  in  twenty-four  hours;  averaging 
between  38|  ounces  and  48|  ounces.  The  adult  averages  40.13 
grains  to  1,000  grains  of  his  weight;  a  child,  72.5  grains.  The  dif- 
ferent proportions  of  water  account  in  great  part  for  the  variations 
above  mentioned  in  the  quantity  of  urine;  but  the  solid  constituents 
are  also  liable  to  considerable  variation,  an  adult  discharging  from 
1:^  ounces  to  2|  ounces  in  twenty-four  hours.  They  are  increased 
by  exercise,  and  diminished  by  sedentary  habits.  Moreover,  if  the 
blood  is  poor  in  albumen  and  abundant  in  salts  (as  in  Bright's  dis- 
ease), the  solid  constituents  are  diminished.  The  mineral  constitu- 
ents also  vary  greatly ;  between  108  and  355  grains  in  twenty-four 
hours — averaging  231.5  grains,  or  nearly  half  an  ounce.  The  urine 
of  women  is  richer  in  water  and  poorer  in  salts  than  that  of  men ; 
and  especially  during  pregnancy.  Ilcnce  the  formation,  in  the 
latter  condition,  of  the  pellicle  improperly  called  kiesteine,  in  the 
manner  already  explained  (p.  89). 

Origin. — Urine  is  directly  eliminated  from  the  blood  by  the  epi- 


URINE, 


221 


thelial  cells  of  the  uriniferous  tubes 
however,  is  doubtless 
obtained  by  mere  trans- 
udation into  the  urini- 
ferous  tubes  from  the 
vessels  which  form  the 
Malpighian  tufts  or  bo- 
dies. Hence  increased 
pressure  of  blood  in  the 
finer  renal  vessels  causes 
increased  separation  of 
water  and  of  the  solids, 
especially  the  salts.  If, 
on  the  other  hand,  the 
arterial  and  capillary 
tension  is  diminished, 
the  secretion  is  also  di- 
minished. It,  however, 
by  no  means  follows,  as 
Lehmann  implies,  that 
the  secretion  of  urine  is 
a  mere  physical  pheno- 
menon, dependent  upon 
the  fact  that  the  blood 
undergoes  compression 
while  in  the  vessels  of 
the  Malpighian  tufts. 
The  more  characteristic 
elements  of  the  urine 
are  separated  by  a  vital 
action  of  the  epithelial 
cells,  and  hence  their 
amount  in  twenty-four 
hours  is  more  nearly 
constant  in  health ;  while 
a  great  part  of  the  water, 
and  of  the  salts  proba- 
bly, when  in  excess  in 
the  blood,  are  separated 
from  the  latter  by  trans- 


A  great  part  of  the  water, 
Fig.  130. 


Structure  of  tho  kiduey.  1.  Ccccal  extremity  of  a  tubulus 
uriniforus.'  2,2.  Eocurrent  loops  of  tubuli.  3,3.  Bifurcations 
of  tubuli.  4,  .5, 6.  Tuliuli  converging  totrards  the  papilla.  ".  7, 
7,  7.  Corpora  Malpighiana  seen  to  consist  of  plexuses  of  blood- 
vessels, connected -(vitli  a  capillary  network.   S.  Arterial  trunk. 


222 


THE    FLUIDS. 


udation  merely.  Fig.  130  shows  the  relations  of  the  uriniferous 
tubes,  arterial  branches,  and  Malpighian  tufts  in  a  section  of  the 
kidney  ;  and  Fig.  131  shows  two  tufts,  with  their  afferent  and  eflfe- 


Fig.  131. 


Fig.  131.  Relation  of  Malpighian  tufts  to  the  vessels,  a.  Branch  of  the  renal  artery,  af.  Afferent 
vessel,  m,  m.  Malpighian  tufts,  ef,  ef.  Efferent  vessels,  p.  Vascular  plexus  surrounding  the 
tubes,     st.  Straight  tube.     ct.  Convoluted  tube.     (Magnified  about  30  diameters.) 

Fig.  132.  Uriniferous  tube  and  its  epithelial  lining,  a.  Portion  of  a  secreting  tube  from  the  cor- 
tical substance  of  the  Ijidney.  b.  The  epithelium  or  gland-cells,  more  highly  magnified  (700  times), 
c.  Portion  of  a  tube  from  the  medullary  substance  of  the  kidney.  At  one  part  the  basement  mem- 
brane has  no  epithelium  lining  it. 

rent  arteries.  Fig.  132  shows  a  uriniferous  tube  with  its  epithelial 
lining,  and,  at  B,  a  few  cells,  derived  from  its  interior,  of  the  scaly 
epithelium  by  which  the  true  urine  is  secreted. 

Uses. — Urine  is  merely  an  excretion,  ^.  e.  it  consists  essentially 
either  of  effete  elements  resulting  from  the  disassimilation  of  the 
tissues,  or  of  others  existing  in  the  blood  in  excess — the  incessant 
removal  of  which  is  essential  to  the  health  of  the  organism. 


Urinary  Deposits. 

Though  normal  urine  is  perfectly  clear  and  transparent  when 
first  emitted  from  the  bladder,  solid  matters  soon  appear  in  it,  form- 
ing a  pellicle  on  its  surface,  or  a  sediment ;  and  which  are  called 
urinary  dejwsits.  These  are  quite  numerous,  as  found  in  various 
normal  and  abnormal  conditions,  and  may  be  divided  into  two 
classes:  1,  histological  elements;  2,  crystalline  substances  of  mine- 
ral and  organic  origin. 

I.  The  Justobgical  elements  have  been  specified  at  the  commence- 
ment of  this  section,  these  being  of  course  all  suspended  in  the 
urine  while  it  is  still  in  the  bladder,  viz: — 


URINE.  223 

1.  Scaly  epithelium.     (Fig.  132.) 

2.  Mucus  and  pus  (cytoid),  corpuscles.     (Figs.  120  and  121.) 

3.  Blood-corpuscles.     (Fig.  123.) 

4.  Albumen.     Heat  and  nitric  acid  solidify  it,  and  make  it  appa- 

rent (p.  86). 

5.  Fibrinous  casts  (three  forms),  together  with  fat-globules.    (Figs. 

123,  124,  and  379.) 

6.  Organic  globules  (two  kinds).     (Figs.  125  and  12(3.) 

7.  Spermatozoids.     (Fig.  116.) 

8.  Fungi  (two  kinds).     (Figs.  127,  128.) 

9.  Sarcina  ventriculi.     (Fig.  129.) 

II.  The  crystalline  (except  carbonate  of  lime)  deposits  of  mineral 
origin : — 

1.  Chloride  of  sodium.     (Figs.  1  and  2.) 

2.  Triple  phosphate.     (Figs.  6  to  9.) 

3.  Carbonate  of  lime  (usually  amorphous).     (Fig.  3.) 

Those  of  organic  origin,  and  their  compounds  with  mineral  sub- 
stances, are : — 

1.  Urea.     (Fig.  37.) 

2.  Uric  acid  (various  forms).     (Figs.  11  to  19.) 

3.  Urate  of  soda.     (Fig.  22.) 

4.  Cystine.     (Fig.  38.) 

5.  Hippuric  acid.     (Fig.  25.) 

6.  Oxalate  of  lime  (various  forms).     (Figs.  26  to  31.) 

Urinary  Concretions.     {Vesical  and  Renal  Calculi.) 

Calculi  in  the  bladder  and  kidneys  are  formed  by  precipitation 
of  the  solids  in  solution  in  the  urine,  around  a  nucleus,  so  called. 
This  is  sometimes  a  foreign  body  introduced  into  the  bladder  from 
without;  and  sometimes  a  particle  of  mucus  or  other  animal  sub- 
stance (and  still  oftener  uric  acid),  formed  within  it.  In  either 
case,  as  soon  as  the  nucleus  is  formed,  the  mineral  constituents  of 
the  urine  may  be  precipitated  around  it,  and  thus  a  calculus  is  con- 
centrically formed.  The  composition  of  the  calculus  will,  of  course, 
depend  upon  the  constituents  precipitated ;  and  very  frequently  it 
happens  that  the  concentric  layers  are  formed  of  difi'erent  sub- 
stances. Such  are  termed  alternating  csdculi;  and  they  alone  de- 
monstrate the  incorrectness  of  the  doctrine  of  diatheses — as  the 
uric  acid  diathesis,  the  phosphatic  diathesis,  &c.     (Fig.  34.) 

Calculi  found  in  the  bladder  may  be  first  formed  in  the  substance 
of  the  kidney.  Calculi  are  also  formed  in  the  prostate  gland  (p. 
54);  but  these  are,  of  course,  not  concretions  from  the  urine. 

The  following  abstract  shows  the  composition  of  353  calculi  in 
Giiy's  Hospital ;  and  of  78  in  the  Museum  of  the  Transylvania 
University  ;  the  last  having  been  examined  by  Dr.  Peter.^ 

'  Bird  on  Urinary  Deposits,  pp.  321-23. 


224 


THE   FLUIDS. 

Nuclei  of 
(( 

u 

11 

uric  acid 
urate  of  soda 
"         lime 
uric  oxide 

Guy 

's  Hosp. 

250 

18 

1 

1 

"           cystine 

"           oxalate  of  lime 

j  lime       2 
"           phosphates  -  triple     1 

(  mixed  19 
"           foreign  substances 
Mixed  calculi 

! 

11 
47 

22 
3 

The  todies  were  composed  of — 
Uric  acid  (Figs.  20,  21)  in 
Urates  of  soda,  &c.     (Fig.  23.) 

Cystine 

Oxalate  of  lime.     (Figs.  32,  33.) 
Triple  phosphate.     (Fig.  10.)      . 
Phosphate  of  lime 
Fusible  mixed  phosphates 
Carbonate  of  line 

The  crust  was  composed  principally  of- 
Uric  acid  in        ...         . 

Urate  of  soda     .... 

Cystine 

Oxalate  of  lime 
Triple  phosphates 
Phosphates  of  lime    . 
Fusible  mixture  of  phosphates 
Carbonate  of  lime 


47 
186 
12 
26 
14 
12 
41 
1 

40 

11 

11 
11 
14 
19 
27 
1 


Trans.  Univ. 
32 
26 


(mixed) 


with 
phosphates 


(mixed  do.) 


34 

2 

2 

16 

4 


34 
2 

2 

9 

2 

37 


The  frequent  occurrence  of  uric  acid  as  a  nucleus  in  the  preced- 
ing calculi  is  remarkable  (p.  63);  and  Lchmann  states  that  a  trace 
of  uric  acid,  if  nothing  more,  may  always  be  detected  in  the  nu- 
cleus of  the  concretion  (Vol.  II.  p.  124).  Scherer  maintains  that  it 
is  an  acid  fermentation  of  the  mucus  in  the  urine,  which  leads  to 
the  first  precipitation  of  the  uric  acid,  and  therefore  mucus  must 
be  first  present  and  form  a  part  of  the  nucleus.  Mere  irritation  of 
the  bladder  may  produce  an  abnormal  mucus,  and  thus  become  the 
first  step  towards  the  foundation  of  the  nucleus.  An  alkaline  fer- 
mentation of  the  urine,  on  the  other  hand,  leads  to  the  deposition 
of  the  phosphates  (as  in  paralysis  of  the  bladder,  &c.);  and  hence 
calculi  may  present  the  alternating  layers  (Fig.  34),  already  de- 
scribed. 


SEBACEOUS   SECRETION. 


225 


V.  The  Lachrymal  Fluid. 

The  lachrymal  fluid  is  a  clear,  transparent  fluid,  the  principal 
elements  of  which  are  water,  common  salt,  and  an  organic  com- 
pound called  by  some  chemists  ladirymine.     Any  mucus-corpus- 
cles or   epithelial  cells  in  it 
come  from  the  mucous  mem- 
brane of  the  eyelids. 

Origin. — This  fluid  is  se- 
creted by  the  epithelial  cells 
of  the  coeca  of  the  lachrymal 
gland.     (Fig.  133.) 

Use. — The  lachrymal  fluid 
lubricates  the  eyeball,  and 
thus  diminishes  friction  be- 
tween it  and  the  eyelid.  In 
case  of  copious  weeping, 
much  of  the  fluid  is  merel}^ 

a    transudation,    mixed    with         conjunctival  or  inner  surface  of  eyelid.    I.  Lachry- 

raal  gland.   <^.  Orifices  of  its  7  ducts  on  the  conjunctiva, 
the  secretion    of   the    lachry-      The  Meibomian  glands  are  seen  running  towards  the 
1   fyln^^l  edges  of  the  lids,    o,  o.  Orbicularis  muscle  beyond  the 

t>  ■  lids.   (Scevimering.) 


CHAPTER    IV. 


THE  CUTANEOUS  SECEETIONS. 


The  secretions  of  the  skin  are  two;  the  sebaceous  secretion  and 
the  perspiratory. 

I.  The  Sebaceous  Secretion. 

This  is  secreted  by  the  sebaceous  follicles  (glands),  situated  in  the 
substance  of  the  corium  of  the  skin.  The  ^[eibomian  and  the 
ceruminous  glands  also  belong  to  this  class. 

The  secretions  of  all  these  glands  are  by  no  means  precisely 
identical.  In  all  of  them,  epithelial  cells  may  be  found  as  a  mor- 
phological element;  the  scaly  cells  of  the  skin  often  predominating 
15 


226 


THE    FLUIDS. 


over  the  conoidal  ones  from  the  interior  of  the  follicles.  In  the 
Meibomian  secretion  and  the  cerumen,  peculiar  oval,  angular,  or 
roundish  cells  are  found,  from  o 4^0(5  ^^  tbVo  of  ^.n  inch  in  diameter, 
containing  a  pale  nucleus  and  nucleoli,  with  minute  dark,  sharply 
defined  granules,  and  a  few  fat-globules. 

When  in  a  state  of  inflammation,  the  sebaceous  follicles,  like  the 
mucous,  produce  (cytoid)  pus  corpuscles.     Mere  irritation  may  also 

give  rise  to   them.     They 
^^'  are  best  seen  in  cases  of 

inflammation  of  the  exter- 
nal auditory  passage,  and 
of  the  Meibomian  glands, 
in  balanitis,  and  in  acne ; 
there  being,  in  these  cases, 
also  an  exudation  in  which 
the  cytoid  corpuscles  are 
developed.  The  parasite 
called  acarus  folJiculorum 
is  often  found  in  the  nor- 
mal secretion  of  the  seba- 
ceous follicles.  (Fig.  134.) 

The  fluid  portion  of  these 
secretions  contains  an  albu- 
minous substance  not  yet 
accurately  recognized.  But  fat  and  lipoids  constitute  the  principal 
part  of  them.  It  constitutes  47.5  per  cent,  of  the  vernix  caseosa 
of  the  full  grown  foetus  {Lehmann\  and  52.8  per  cent,  of  the  smegma 
of  the  human  prepuce.'  It  has  been  ascertained  that  the  liquor 
amnii  contains  most  fat  at  the  end  of  pregnancy;  it  being  derived 
from  the  sebaceous  follicles  of  the  foetus.  In  the  vernix  caseosa 
many  hairs  are  always  to  be  found;  this  tissue  being  intimately 
associated  with  the  sebaceous  follicles,  as  will  be  shown.  The  mar- 
garates  and  oleates  of  potash,  soda,  and  ammonia  are  also  elements 
of  these  secretions.  Cholestcrine  is  found  in  the  smegma  prreputii, 
and  a  substance  very  similar  to  it,  but  not  crystallizable,  in  vernix 
caseosa.  Berzelius  found  a  peculiar  fatty  substance  in  the  ce- 
rumen. 

The  sebaceous  follicles  arc  always  situated  close,  or  very  near,  to 


Entozoa  from  the  sebaceous  follicles,  n.  Two  seen  in 
their  ordinary  position  in  the  orifice  of  one  of  the  seba- 
ceous follicles  of  the  scalp,  h.  Short  variety,  c.  Long 
variety. 


'  KoUiker  asserts  that  the  smegma  pr.Tputil   is  formed  almost  exclusively  of 
the  ejtitlielial  cells  of  the  prepuce.     (See  Chapter  X.) 


SEBACEOUS   SECRETION. 


22i 


the  liair  follicles,  and  often  open  into  them ;  except  that  on  the 
nymphae  and  the  glans  penis,  and  on  the  inner  surface  of  the  pre- 
puce, these  follicles  exist  while  hairs  do  not.  (Fig.  135.)  Vauquelin 
examined  the  fat  of  human  hair,  and  found  it  oleaginous,  colored, 
and  containing  sulphur. 

The  mineral  constituents  of  these  secretions  are,  a  little  chloride 
of  sodium  and  hydrochlorate  of  ammonia,  with  phosphate  of  am- 
monia and  soda.  Earthy  phosphates  are,  however,  more  abundant: 
the  vernix  caseosa  contains  6.6  per  cent,  and  the  smegma  prteputii 
9.7  per  cent. 

Of  tvater,  the  vernix  caseosa  contains  from  06.98  to  77.87  per 
cent.  In  the  sebaceous  secretions  after  birth  it  must  be  constantly 
varying  with  the  hygroraetric  and  thermometric  states  of  the  sur- 
rounding air. 

The  castoreum  used  as  an  antispasmodic  is  merely  the  smegma 
from  the  preputial  folds  of  the  penis  and  the  clitoris  of  the  beaver 
Canadian  castor  contains  5.8  per  cent,  of  albuminous  matter,  8.249 
of  fatty  matters,  and  41.34  of  resinous  constituents.  [Lehmcmn.) 

Origin. — The  sebaceous  secretions  are  secreted  by  the  epithelial 
cells  of  the  various  forms  of  sebaceous  glands.     Figs.  135, 136,  and 

Fig.  135. 


Sebaceous  follicles  of  skin  in  ti:eiv  relation  to  tlic  hairs. 


137  show  the  forms  of  the  simple  sebaceous  follicles  of  the  skin, 
and  the  Meibomian,  and  the  ceruminous  glands. 


228 


THE    FLUIDS. 


Fig.  136. 


Fig.  137. 


Meibomian  gland,     a.  Basement  mem- 
brane.    &.  Epithelial  cells,     c.  Duct 


Ceruminous  gland,  highly  magnified.  1,1.  Tube  form- 
ing the  gland.  2.  The  excretory  duct.  3.  Vascular  trunk 
and  its  ramifications. 


Functions. — The  sebaceous  secretion  diminishes  the  tendency  to 
evaporation  from  the  hair  and  the  epidermis;  and  thus  prevents  the 
drying  up  of  the  deeper  layers  of  the  epidermis,  and  consequently 
of  the  corium. 

The  Meibomian  fluid  prevents  the  lachrymal  fluid  from  flowing 
directly  over  the  lids,  from  the  conjunctiva;  and  the  cerumen  both 
secures  a  proper  moisture  of  the  auditory  passage,  and,  by  its  nau- 
seous odor,  deters  insects  from  entering  it. 


II.  Perspiration. 

True  perspiration  (sweat)  is  the  fluid  secreted  by  the  perspiratory 
glands,  which  are  situated  beneath  the  skin,  in  the  subcutaneous 
areolar  tissue.  They  are  delicate  tubes,  forming  twisted  coils  at 
their  commencement,  from  which  they  pass  in  a  vertical  direction 
through  the  corium  of  the  skin,  and  in  a  spiral  or  cork-screw  man- 
ner through  the  epidermis,  to  open  upon  the  surface  of  the  latter 
with  a  somewhat  contracted  mouth.  Fig.  138  represents  one  of 
these  glandular  coils,  with  a  part  of  its  duct. 

Sweat,  as  collected  on  the  skin,  is  a  colorless,  very  watery  fluid, 


PERSPIRATION. 


22y 


Sweat-gland  and  part  of  its  duct.  a.  Venous 
radicle,  h.  Capillary  plexus  separated  from 
the  gland,  and  rising  from  arteries  whicli  also 
anastomose. 


with  a  saltish  taste  and  more  or  Fig.  138, 

less  intense  odor,  and  generally 

presenting  a  weak  acid  reaction. 

The  sweat  from  the  axillas  and  the 

feet  is,  however,  often  found  to  be 

alkaline. 

There  are  no  morphological  ele- 
ments ill  sweat,  except  the  scaly 
epithelial  cells  of  the  skin,  which 
are  accidentally  present. 

The  solid  constituents  of  sweat 
probably  do  not  exceed  1.26  per 
cent. ;  Favre  says  .443  per  cent, 
only.  Of  the  solid  constituents, 
chloride  of  sodium  is  the  most 
abundant.  The  salts  of  ammonia 
are  also  present  in  it.  Earthy  phosphates  and  a  little  peroxide  of 
iron  are  also  present,  but  these  are  probably  derived  from  the  epi- 
thelial cells  in  the  fluid. 

The/a^;  in  the  sweat  may  probably  be,  in  great  part,  derived  from 
the  sebaceous  follicles.  But  Krause  has  found  that  the  sweat-glands 
also  secrete  fat,  to  some  extent.  Lehmann  has  proved  that  it  con- 
tains butyric  acid. 

Sweat  also  contains  the  acetic  and  formic  acids  (Schottm),  and  the 
lactic  {Favre),  and  a  sulphurous  matter  {Lehmann).  Urea  is  also  a 
normal  constituent.  {Favre.)  The  thin  bluish  layer  sometimes  found 
on  the  bodies  of  persons  who  have  died  of  cholera  is  a  fine  powder, 
composed,  for  the  most  part,  of  urea.  Certain  pigments  sometimes 
occur  in  sweat,  especially  that  of  the  bile  in  cases  of  icterus. 

It  has  also  been  demonstrated  that  gases,  especially  carbonic  acid 
and  nitrogen,  are  given  off  in  the  liquid  secretion  of  the  sudoripa- 
rous glands,  and  these  must  not  be  overlooked  in  determining  the 
functions  of  the  skin.  The  carbonic  acid  predominates  in  case  of 
a  vegetable,  and  the  nitrogen  of  an  animal,  diet.  But  less  gas  is,  on 
the  whole,  given  off  when  the  perspiration  is  active,  as  after  brisk 
exercise. 

The  amount  of  perspiration,  in  twenty-four  hours,  averages,  in 
case  of  an  adult  man,  not  far  from  25  J  ounces.  (  Valentin.)  Krause 
calculated  25y'''g  oances  of  water,  ^  ounce  of  organic  and  volatile 


230  THE    FLUIDS. 

matters,  and  88  grains  of  mineral  substances.  An  adult  man,  in  a 
vapor-bath,  loses  f  ounce  of  sweat  in  a  minute.  {Lehmann.) 

About  412  cubic  inches  of  carbonic  acid  gas  are  excreted  from 
the  skin  of  a  full-grown  man,  in  twenty-four  hours,  and  a  little  less 
than  one-half  as  much  nitrogen,  {Ahernethy^ 

Origin. — It  has  already  been  shown  (p.  181)  that  a  transudation  is 
constantly  occurring  upon  the  surface  of  the  skin,  as  a  mere  phy- 
sical necessity;  and  doubtless  very  much  of  the  fluid  collectively 
called  the  sweat  is  produced  in  this  way.  The  precise  proportion 
of  the  true  sweat,  however,  cannot  be  ascertained.  Certainly,  when 
the  amount  of  perspiration  is  very  suddenly  augmented,  as  in  a. 
vapor-bath,  it  cannot  be  due  to  secretion  wholly  nor  principally. 
But  while  secretion  is  probably  thus  increased,  transudation  is  in- 
creased to  a  much  greater  proportional  extent.  In  cases  of  colli- 
quative sweats,  and  the  cold  sweat  so  common  in  articuh  mortis^  it 
is  certainly  not  increased  secretion,  but  mere  transudation,  which 
produces  the  excess  of  fluid. 

Besides,  it  is  probable  that  the  gases  escaping  by  the  skin  do  so 
as  a  mere  physical  phenomenon,  whether  termed  exhalation  oi- 
otherwise. 

So  far,  therefore,  as  the  sweat  is  actually  a  secretion^  it  is  doubtless 
secreted  by  the  epithelial  cells  lining  the  tubes  forming  the  per- 
spiratory glands.  But  the  portion  elaborated  by  them  constitute^ 
the  insensible  rather  than  the  sensible  perspiration ;  and  though  it 
is  highly  probable  that  it  contains  all  the  substances  mentioned  as 
more  characteristic  of  the  sweat — as  lactic,  formic,  and  butyric 
acids — nothing  positive  is  known  on  this  point. 

Uses. — One  use  of  the  sweat  is,  doubtless,  to  regulate  the  tem- 
perature of  the  animal  body ;  an  excess  of  perspiration,  and  its 
evaporation,  being  a  cooling  process. 

But  the  main  object  of  the  perspiration  is  the  elimination,  it  is 
said,  of  certain  deleterious  elements  from  the  blood,  it  being  one  oi' 
the  excretions.  When  we  consider  that  more  than  99|  per  cent,  of 
the  sweat  is  water  {Favre),  it  hardly  appears  possible  that  this  ex- 
creting power  of  the  perspiratory  glands  has  not  been  overrated. 
Yet  all  physicians  are  aware  of  the  serious  consequence  resulting 
from  a  sudden  "check  of  the  perspiration,"  so  called. 

We  doubt  not  that  the  perspiratory  glands  do  eliminate  excre- 
mentitious  substances,  and  that  their  function  is  therefore  important. 
But   it  is  probable  that  tlic  gases  and  volatile  substances  which 


PERSPIRATION.  281 

escape  from  the  surface  of  the  skin  by  mere  exhalation  and  trans- 
udation are  far  more  important  as  excretions  than  the  actual  ele- 
ments of  the  perspiration.  It  is,  therefore,  probably  because  the 
action  of  the  shin  as  an  exhaling  and  transuding  surface  is  suddenly 
checked,  and  not  that  of  the  perspiratory  glands  alone,  that  such 
serious  consequences  ensue  from  such  sudden  changes.  It  is  far 
more  because  carbonic  acid  and  nitrogen  gases,  and  water  also,  cease 
to  be  given  ofif,  than  because  the  perspiratory  elements  and  the 
minute  amounts  of  the  acids  of  the  sweat  are  still  retained  in  the 
blood,  that  the  mischief  results.  And  it  is  not  singular  that  the 
pulmonary  surface,  or  that  of  the  alimentary  canal,  or  of  the  urini- 
ferous  tubes,  should  manifest  a  higher  amount  of  power  as  a  trans- 
uding surface  when  this  physical  process  is  suddenly  checked  on 
the  skin ;  and  that  catarrhs,  diarrhoeas,  or  diuresis  should  result 
therefrom. 


THIRD  DIVISION. 

THE  TISSUES. 

CLASSIFICATION  OF  THE  TISSUES. 

No  classijBcation  of  the  tissues  is  possible  wliicli  is  not  liable  to 
some  objections ;  but  the  following  is  proposed  as  the  most  simple, 
for  the  use  of  the  student  in  histology.  All  tissues  in  which  the 
microscope  detects  but  one  of  the  simple  histological  elements — 
whether  cells,  fibres,  or  membrane — are  termed  simple  tissues;  while 
if  two  or  more  elements  are  seen — as  cells  and  fibres,  or  cells,  fibres, 
and  homogeneous  substance — such  are  termed  compound  tissues. 
And  the  latter  are  termed  binary  or  ternary,  if  constituted  respect- 
ively of  two  or  three  elements. 

In  any  classification,  the  distinction  between  mere  tissues,  and 
organs  consisting  in  great  part  of  those  tissues,  must  be  kept  in 
mind.  E.  g.  white  fibrous  tissue  constitutes  a  great  part  of  the 
ligaments  and  tendons;  but  mere  white  fibrous  tissue  is  one  thing, 
while  a  tendon  or  a  ligament  is  another — the  latter  containing 
bloodvessels  and  areolar  tissue,  together  with  much  of  the  tissue  in 
question.  So  bone-tissue,  or  osseous  tissue,  is  a  simjjie  tissue;  but 
a  bo7ie  is  a  compound  organ^  consisting  of  osseous  tissue,  vessels, 
nerves,  lymphatics,  &c. 

We  must  also  distinguivsh,  in  a  classification,  the  tissue  itself, 
from  mere  cavities  which  are  found  in  it.  Even  though  the  latter 
may  be  peculiar  to  the  tissue,  and  characteristic,  they  constitute  no 
part  of  it  whatever,  and  must  exert  no  influence  in  deciding  to 
what  class  the  tissue  belongs.  These  remarks  apply  more  espe- 
cially to  osseous  tissue,  this  being  a  simple  tissue;  though  the 
cavities  (lacunas  and  pores)  are  more  characteristic  of  bone,  as  seen 
under  the  microscope,  than  is  even  the  solid  substance  itself. 

Dental  tissue  is  here  associated  with  the  osseous,  though  the 
enamel  is  more  nearly  allied,  in  its  method  of  development,  to  epi- 


CLASSIFICATION   OF   THE   TISSUES.  233 

thelium.  The  nails  and  the  hair  arc  classed  with  epithelium  also; 
though  the  latter  is  often  classed  with  teeth,  and  is,  at  the  same 
time,  a  compound  tissue. 

Only  the  highest  form  of  muscular  tissue  (the  striated)  is  strictly 
compound;  but  there  is  an  obvious  advantage  in  arranging  and 
describing  the  two  forms  in  connection. 

The  fat-ce//5  are  a  simple  tissue;  but  adipose  tissue  is  not  so,  and 
hence  it  is  placed  in  the  second  class.  It  would  be  in  accordance 
with  analogy  to  term  the  fat-cells  alone  fatty  tissue^  and,  when  con- 
nected together  with  their  vessels  by  areolar  tissue,  to  apply  the 
term  fat — as  we  speak  of  osseous  tissue  and  bone,  of  muscular 
tissue  and  muscle.  In  that  case  the  term  adipose  tissue  might  be 
dropped,  or  adipose  tissue  and  adipose  might  be  used.  For  the  pre- 
sent, however,  it  appears  necessary  to  retain,  as  correlative  terms, 
fat-cells  and  adipose  tissue. 

It  will  be  hereafter  seen  that  the  mucous  and  serous  membranes, 
and  the  skin,  are  composed  of  the  same  histological  elements;  and 
they  are,  therefore,  here  classed  together.  The  vessels  and  the 
heart  present  no  peculiar  histological  elements ;  but  they  are  sepa- 
rately described  on  account  of  their  great  physiological  importance. 
For  a  similar  reason,  distinct  chapters  are  devoted  to  the  alimentary 
canal,  tlie  urinary,  the  sexual,  and  the  respiratory  apparatus,  tke 
ductless  glands,  and  the  sensory  organs. 

Classification  of  the  Tissues. 

First  Class.— SIMPLE  TISSUES. 

1.  Epithelium.     Hair  and  Nails. 

2.  Yellow  Fibrous  (Elastic)  Tissue. 

3.  White  Fibrous  (Collagenous)  Tissue. 

4.  Osseous  Tissue,  including  Teeth. 

Second  Class.— COMPOUND  TISSUES. 

1.  Areolar  Tissue. 

2.  Adipose  Tissue. 

3.  Cartilage  and  Fibro-Cartilage. 

4.  Contractile  or  Muscular  Tissue  (two  forms). 

5.  Nervous  Tissue — Vesicular  and  Fibrous. 

f  Cutaneous  (Skin.) 
6.  The  Membranes  -  Mucous. 
y  Serous. 

7.  The  Vessels. 

8.  Alimentary  Canal  and  Appendages. 

9.  Urinary  Apparatus. 


234  THE   TISSUES. 

10.  Sexual  Organs. 

11.  Respiratory  Organs. 

{The  Spleen. 
The  Thyroid  Body. 
The  Thymus  Body. 
The  Supra-Renal  Capsules. 
13.  Tlie  Organs  of  the  Senses. 

In  order,  however,  to  avoid  repetitions  as  far  as  possible,  and  to 
proceed  at  the  same  time  in  the  most  intelligible  manner,  the  first 
seven  tissues  will  be  described  in  the  following  order;  after  which 
muscular  tissue  and  the  rest  will  follow  in  the  order  already  given. 

1.  Epithelium  and  its  modifications. 

2.  Yellow  fibrous  tissue. 

3.  White  fibrous  tissue. 

4.  Areolar  tissue. 

5.  Adipose  tissue. 

6.  Cartilage  and  Fibro-Cartilage. 

7.  Osseous  tissue  and  the  Bones; 
Dental  tissues,  and  the  Teeth. 

8.  Contractile  or  Muscular  tissue,  &c.  &c. 


CHAPTER    I. 

EPITHELIUM — NAILS   AND   HAIR. 

The  epidermis  and  the  nails  have  been  by  some  authors  termed 
the  horny  tissues;  since,  like  the  claws,  horns,  and  hoofs  of  the  lower 
animals,  and  whalebone,  so  called,  and  tortoise-shell — they  contain 
the  immediate  principle  called  Keratine  (p.  100).  Both  these,  how- 
ever, and  the  epithelia  of  mucous  and  serous  membranes,  are  histo- 
logically so  similar,  that  they  will  be  described  under  the  head  ol' 
epithelium ;  and  the  hair,  next  in  ordei',  as  being  an  epithelial 
appendage. 

All  epithelial  developments  are  destined  to  fall  ofl",  and  thus  bo 
lost  to  the  organism,  after  accomplishing  their  proper  functions ; 
and  they  all  consist  of  cells  of  various  forms  which  have,  in  a  mea- 


El'miKLlUM — ElM  DERMIS,  ETC,  2B5 

sure,  dried  up  if  externally  situated,  and  which  are  agglutinated  to 
each  other  by  an  intercellular  substance  difficult  of  detection.  Be- 
sides this  last  "problematical  substance"  {Lehmann),  there  are  threc^ 
distinct  elements  of  the  cells:  1,  the  substance  of  the  cel\-mem- 
hranes^  which  constitutes  the  principal  portion  of  all  these  tissues: 
and,  which  is  almost  insoluble  in  alkalies;  2,  thecell-con^e?i/'.s,  which, 
with  the  nucleus,  are  more  readily  soluble  in  alkalies;  and  3,  the 
granular  matters  which  are  wholly  insoluble  in  alkali.  The  last 
remain  after  the  entire  solution  of  some  of  these  tissues,  and  by 
no  means  consist  entirely  of  fat. 

They  all  contain  a  considerable  amount  of  unoxidized  sulphur, 
and  usually  about  one  per  cent,  of  mineral  substances  in  all. 

SECTION   I. 
EPITHELIUM    (epidermis,    ETC.). 

Every  free  surface  of  the  body  is  covered  by  one  or  more  layers 
of  cells,  constituting  an  ejnthelium.^  Epithelium,  therefore,  enters 
into  the  structure  at  every  point  of  the  skin,  and  of  serous  and 
mucous  membranes,  forming  the  outermost  {i.e.  farthest  from  the 
vessels),  of  the  three  layers  of  which  they  are  alike  composed. 
The  next  layer  underneath  the  epithelium  is  the  basement-mem- 
brane, already  described  (p.  Ill),  and  the  innermost,  the  corium. 
Viewed  in  its  histological  relations,  therefore,  epithelium  may  be 
defined  to  be  a  continuous  expansion  of  cells ;  consisting  of  one  or  more 
strata  devehjxd  upon  and  comjpletely  covering  a  hasement-memhrane. 
A  single  layer  of  cells  constitutes  a  simple^  and  two  or  more  layers 
a  compound  epithelium. 

The  epithelium  of  the  skin  is  usually  called  epidermis  or  cuticle. 
These  terms,  however,  include  only  the  outer  layers  of  the  cuta- 
neous epithelium,  as  will  be  shown.  The  epithelia  of  the  skin  and 
of  mucous  membrane,  are  of  course  continuous  where  these  mem- 
branes are  so ;  as  at  the  mouth,  nostrils,  anus,  &c. 

Epithelial  cells  present  no  original  peculiarities  o^  form  and  con- 
tents. They  consist  of  cell- wall,  contained  fluid,  granules,  nuclei,  and 
nucleoli  (p.  114).  On  some  portions  of  the  mucous  membrane,  how- 
ever, they  assume  a  conoidal  or  elongated  (cylindrical)  form ;  while 
on  serous  membranes  the  contact  of  the  opposed  surfaces  gives 
them  a  very  flat  form,  allowing  but  a  small  amount  of  fluid  con- 

'  From  i-nl  iipou,  and  dr.xh  the  nipple — it  being  very  apparent  on  this  part. 


236  THE   TISSUES. 

tents;  and  on  the  skin  tlie  outer  strata  of  cells  become  dried  and 
collapsed  into  solid  horny  scales.  In  the  first  instance,  the  epithe- 
lium is  termed  a  conoidal  (or  cylinder),  and  in  the  latter  case,  a 
scaly  epithelium.  Between  the  conoidal  and  the  flattened  cell,  many 
varieties  are  found;  the  globular  and  the  polyhedral  form  predo- 
minating. 

Again,  the  conoidal  cells  are  sometimes  found  surmounted  by 
cilia,^  so  called;  in  which  case  we  have  a  ciliated  epithelium. 

The  conoidal  (or  cylinder)  and  the  ciliated  epithelium  are  found 
only  on  the  mucous  membrane,  in  the  adult  human  body ;  the  scaly 
variety  exists  everywhere  on  the  skin  and  serous  membranes,  and 
also  on  certain  parts  of  the  mucous  membranes,  hereafter  to  be 
specified. 

The  granules  are  more  numerous  in  epithelial  cells  in  proportion 
as  the  latter  are  smaller  and  younger,  and  in  these  also  the  circular 
or  oval  nuclei  are  more  apparent.  Acetic  acid  renders  them  very 
distinct.  Indeed,  the  granular  appearance  and  the  distinctness  of 
the  nuclei  seem  to  measure  the  functional  activity  of  the  cells,  and 
when  both  disappear  the  cells  become  detached  or  desquamated. 

The  size  of  epithelial  cells  varies  according  to  their  form,  and 
also  in  different  parts  of  the  body,  and  in  the  different  layers  in 
the  same  part.  The  conoidal  cells  of  the  epithelium  of  the  small  in- 
testine are  iy'25  to  g|g  of  an  inch  in  length,  and  -g^Vo  ^^  2s'o«  ^^ 
an  inch  broad.  The  cells  in  the  most  superficial  layer  of  the 
conoidal  epithelium  of  the  larynx  are  77^5  to  5^^  of  an  inch  long, 
and  45^5^  to  2g'(5(j  of  an  inch  broad.  In  the  very  lowest  layers  of 
the  epithelium  of  the  mouth,  when  the  cells  are  arranged  nearly 
perpendicular  to  the  basement-membrane,  they  are  jgVu  ^^  t  4*0 15  ^^ 
an  inch  long;  in  the  middle  layers  they  are  ^^^-q  to  j^Vu  ^^  ^^^  ino^ 
Ijroad,  having  become  somewhat  flattened ;  while  the  most  super- 
ficial cells  are  large  flattened  [)lates,  called  epithelial  plates^  by  Kol- 
liker — ^\^  to  even  ^^,j  of  an  inch  across.  (Fig.  l-iT.) 

The  thickness  of  the  epithelium  must  depend  on  the  size  of  the 
cells  and  the  number  of  layers.  The  small  intestine,  having  but  a 
single  layer,  will  have  an  epithelium  y j^j  to  g.^g  of  an  inch  thick, 
as  has  been  shown.  The  compound  epithelium  of  the  mouth  is 
rl  2  ^^  5  5  ^f  ^^1  mc\\  thick;  and  that  of  the  larynx  is  ^Jg  to  ^g^  of 
an  inch  thick. 

'  From  "Ciliura,"  an  eyeLasli ;  since  they  resemlilo  fine  hairs. 


EPITUELIUM. 


287 


Varieties  of  Epithelium. 
Both  the  scahj  and  the  conoidal  epithelium  present  two  varieties, 
the  simple  and  the  compoimd.     The  conoidal  epithelium  is  also  in 
some  parts  ciliated,  whether  simple  or  compound.     Thus  we  find — 

I.  The  simple  scaly  epithelium, 

II.  The  compound  scaly  epithelium. 
III.  The  simple  conoidal  epithelium. 
lY.  The  compound  conoidal  epithelium, 

V.  Either  of  the  two  preceding  may  be  ciliated. 

Frequently  the  cells  of  a  scaly  epithelium  (as  on  serous  mem- 
branes) are  matched  together  in  such  a  way  that  its  free  surface  re- 
sembles mosaic  or  a  pavement,  when  seen  under  the  microscope,  the 
cells  being  polygonal  and  mostly  hexagonal.  This  appearance  has 
given  rise  to  the  expression  "pavement  or  tessellated"  epithelium. 
But  the  free  surface  of  a  conoidal  epithe- 
lium often  presents  the  same  appearance;  and 
since  it  depends  not  on  the  size  of  the  cells, 
nor  even  their  form,  except  so  far  as  their 
free  surface  is  concerned,  there  is  no  sufficient 
reason  for  making  this  appearance  a  distin- 
guishing characteristic.  It  is  indicated  in 
Fig.  139. 

Todd  and  Bowman  have  described  the 
epithelium  lining  the  minute  ducts  of  the 
true  glands  as  consisting  of  globular  cells, 
and  hence  term  this  "globular  or  glandular" 
epithelium.  They  suppose  that  the  secretion  of  the  gland  is  secreted 
by  these  cells  alone.  Since,  however,  all  epithelial  cells  secrete  in 
proportion  to  their  size  and  fluid  contents,  this  distinction  is  unne- 
cessary. Besides,  these  cells  are  not  by  any  means  uniformly  glo- 
bular. There  are  all  intermediate  phases,  so  far  as  the  form  of  the 
cells  is  concerned,  between  the  flattened  or  scaly  and  the  conoidal 
or  cylindrical. 

It  will  appear  that  different  functions  are  assigned  to  these  differ- 
ent varieties  of  epithelium,  now  to  be  described. 


Tessellated  (scaly)  epithelium 
of  a  tubulus  nriniferus. 


233 


THE   TISSUES. 


Scaly  epithelium  of  serous  mombrane. 
".  A  fold  showing  thickness  of  the  cells 
;it  its  dark  edges,  h.  One  of  the  nuclei. 
<?.  Line  of  junction  of  two  colls.  (Mag- 
nified 300  diameters.) 


I.  Scaly  Epithelium. 

A.  The  simple  scah/  or  squamous  epithelium  consists  of  a  single 
lajer  of  flattened  cells,  of  a  polygonal  outline.    Fig.  140  shows  the 

epithelium  of  a  serous  membrane. 

Distribution. — This  kind  of  epithe- 
lium is  found  covering  all  true  serous 
(but  not  synovial)  surfaces.  It  also 
lines  all  lymphatics  and  bloodvessels 
throughout,  and  all  mucous  follicles, 
the  air-cells  of  the  lungs,  and  the  ulti- 
mate follicles  of  all  true  glands.  It 
also  covers  the  membrane  of  Demours, 
the  posterior  surface  of  the  iris  (uvea), 
the  inner  surface  of  the  choroid  coat 
(the  pigment-cells  described  on  page 
133,  there  forming  a  scaly  epithelium), 
and  the  capsule  of  the  crystalline  lens ; 
and  lines  the  internal  ear  and  the  Graa- 
fian vesicle. 

The  simple  scaly  epithelium  lining  the  seminiferous  tubes  merges 
into  the  simple  conoidal  at  the  head  of  the  epididymis,  and  thence 

the  latter  variety  lines  the 
vas  deferens. 

Peculiarities. — In  some 
of  the  large  arteries  and 
some  of  the  veins,  the  epi- 
thelial cells  are  quite  ir- 
regularly elongated,  fusi- 
form, and  slender,  being 
t^o  6 Jo  of  an  inch 
Being  also  not  per- 
matched  to  each 
narrow  spaces  are 
and  there  left  be- 
them.  (Fig.  141.) 
Distinct  and  well-marked 
epithelium  may  be  traced 
in  vessels  only  j ^l^^  to  ,  g'^^  of  an  inch  in  diameter.  In  the  walls 
of  the  capillaries,  however,  only  scattered  nuclei  can  be  seen;  which. 


Kpithelial  cells  of  aorta  (horse).  Tlie  largo.-it,  with  dark 
nuclei,  are  magnified  400  diamotors;  the  otiicrs  200  dianie- 
terg.    The  10  smaller  at  the  right  arc  mere  nuclei. 


1  IJF 

long. 

fcctly 

other, 

here 

tween 


EPITHELIUM. 


239 


Fig.  142. 


increasing  in  number  and  development  as  the  vessels  increase  in 
size,  may  be  the  rudiments  of  epithelial  cells.     Fig, 
142  shows  the  epithelium  of  the  lymphatic  vessels. 

The  epithelial  cells  of  the  salivary  glands  contain 
a  greater  amount  of  fatty  and  pigment-granules  than 
occur  in  most  mucous  glands. 

The  cells  of  the  seminiferous  tubes  are  smaller 
before  puberty.  At  that  period  they  increase,  and 
assume  a  higher  function' — the  secretion  of  semen. 
They  merge  into  conoidal  epithelium  at  the  head  of 
the  epididymis,  as  already  stated. 

The  epithelium  of  the  left  ventricle  and  auricle  of 
the  horse  is  seen  in  Figs,  143  and  144,  Nucleated  epithe- 

The  epithelium  of  the  Graafian  vesicle  constitutes    "^^  "f^"^  ^^""p^^' 

i  tics  of  a  horse.  (Mag- 

what  is  termed  the  "membrana  granulosa,"  and  con-    nifieii 320 diameters.) 


Fio;.  143. 


Fig.  144. 


Epithelium  of  left  ventricle  of  a  horse. 
(Magnified  200  diameters.) 


Epithelium  of  left  auricle  of  a  horse,  showing  the 
rounded  and  the  pointed  forms  of  the  cells.  (Magnified 
200  diameters.) 


sists  of  roundish,  polygonal,  nucleated  cells,  g^y'j^  to  ogVs  of  c^n  inch 
in  diameter.     They  become  club-shaped  about  the  time  the  ovum 


Fiff.  145. 


Membrana  granulosa  of  ovum  of  bitch  during  heat.  A.  The  elongated  form  and  stellate  arrau^o- 
ment  of  its  cells  around  the  zona  pellucida.  b.  The  same  ovum  after  the  removal  of  most  of  it.'^ 
club-shaped  colls. 


240 


THE   TISSUES. 


leaves  the  ovary.  They  contain  yellowish  fatty  granules,  which 
become  indistinct  after  the  death  of  the  animal.  (Fig.  145.) 

The  epithelial  lining  of  serous  membranes  (Fig.  140)  gives  their 
surface  a  glassy  lustre,  and  lubricates  it  by  its  secretion.  A  part, 
however,  of  the  serum  in  serous  cavities — the  water  more  espe- 
cially— doubtless  enters  them  by  mere  transudation  from  the  blood- 
vessels. In  inflammations  the  epithelium  is  detached,  and  the  sur- 
face of  the  membrane  then  becomes  somewhat  rough,  and  of  a  dull, 
leaden  hue. 

Kolliker  asserts  that  this  kind  of  epithelium  is,  in  the  ventricles 
of  the  brain  of  embryos,  surmounted  with  cilia. 

B.   Compound  Scaly  Epithelium. 
This  kind  of  epithelium  consists  of  several  layers  of  cells,  the 

outermost  of  which  assume  the  form  of  dry  scales,  or  become  very 

much  flattened  cells.    (Fig.  146.) 

Distribution. — Compound  scaly  epithelium  covers  the  synovial 

membranes  generally.  On  the  mucous  membrane  it  is  found  lining 
the  alimentary  canal  from  the  lips  to  the 
cardiac  orifice  of  the  stomach,  and  the  lower 
half  or  more  of  the  rectum.  It  also  extends 
into  the  nostrils  a  short  distance,  and  lines 
the  lachrymal  canals,  the  conjunctiva,  and 
the  cavity  of  the  tympanum,  except  the 
inner  surface  of  the  membrana  tympani. 
It  extends  through  the  female  urethra,  the 
vagina,  and  the  lower  third  of  the  cavity  of 
the  uterus  (but  not  through  its  neck),  and 
covers  the  clitoris  and  nymphre.  Finally,  it 
lines  the  bladder,  ureters,  and  pelvis  of  the 
kidneys,  in  both  sexes. 

The  compound  scaly  epithelium  also  eve- 
r3nvhcre  forms  the  outer  layer  of  the  skin, 
and  is  here  called  the  epidermis.  In  the 
latter  the  scales  are  dry  and  horny,  as  before 
stated.  Figs.  146  and  68  show  its  vertical 
Vertical  soction  of  opidorinis    scctiou ;  the  cutirc  cpithclium  of  the  skin 

of  palm  of  hand    a  Outer  por-    j     |  ^^j      ^^^  ^^^  epidcrmis  and  the  rete 

tion,compoKedol  flattened  scales.  ^  o  i 

h.  Inner  portions,  of  nucleated    mucosum,  as  it  is  improperly  called. 

cellB.    c.  Portion  of  perspiratory  _,         ,.       .   .  j^-.  -.it  z'  aT-        ^' 

dnct.  (Magnified  155  diameters.)        Pec?tZian^ie5.— Thc  cpiLhclium  of  the  skin 


EPITHELIUM. 


241 


varies  much,  in  dilTerent  parts,  in  thickness.  Its  outer  portion  con- 
stitutes the  cuticle^  and  its  inner  part  the  rete  mucosum,  or  stratum 
Malpighii,  of  anatomists. 

The  outer  layers  of  cells  in  case  of  the  mucous  membrane  also 
become  flattened  into  coherent  scales  (the  epithelial  plates).  These 
may  be  detached  in  flakes  or  sheets  from  the  oesophagus,  and  are 
often  so  by  disease,  from  the  tongue.  (Fig.  14:7.)     The  epithelium 

Fig.  147. 


Epithelial  plates  of  oral  cavity,    a.  Large.    6.  Middle-sized,    c.  Same,  with  two  nuclei. — Magnified 

350  diameters.  (KoUiker.) 

upon  this  organ  is  sometimes  even  ^'jj  of  an  inch  thick.  Still,  it  is 
very  endosmotic,  various  fluids  penetrating  it  from  without,  and 
the  blood-plasma  also  exuding  through  it  from  the  vessels  which 
underlie  it.  {Kolliker?) 

In  the  loioer  animals  we  find  various  modifications  of  this  epithe- 
liiim — as  in  the  sheaths  of  the  beaks  of  birds  and  of  Chelonian 
reptiles;  in  the  scales  of  fishes;  in  the  jaws  of  certain  invertebrate 
animals ;  in  whalebone  so-called,  tortoise-shell,  and  the  teeth  of  some 
fishes;  in  the  spines  and  plates  of  the  tongues  of  many  animals, 
and  the  spines  of  the  oesophagus  of  the  Chelonia ;  in  the  teeth-like 
appendages  of  the  stomachs  of  some  of  the  mollusca,  and  the  horny 
plates  of  the  gizzards  of  most  birds,  and  of  the  cardiac  half  of  the 
stomach  of  the  horse. 


II.  CoNoiDAL  Epithelium. 
A.  Simple  Conoidal  Epithelium. 
This  variety  of  epithelium,  consisting  of  a  single  layer  of  conoidal 
cells,  is  represented  by  Figs.  148,  149,  and  150. 

Distribution. — It  commences  at  the  cardiac  orifice  of  the  stomach. 
It) 


242 


THE   TISSUES. 


and  lines  the  whole  alimentary  canal  thence  to  the  rectum  (Kcilliker 
says,  to  the  anus).     It  lines  the  excretory  ducts  of  all  glands;  the 


Fig.  148. 


Fig.  149. 


B  c 


Fig.  148.  Simple  conoidal  epithelium  of  inner  surface  of  stomach  and  Its  faruli.  a.  Free  ends 
of  epithelial  cell.?,  h.  Nuclei  visible  at  a  deeper  level,  c.  The  free  ends  seen  obliquely,  d.  Deeper 
ends  of  do.  near  which  are  the  oval  nuclei  (.300  diameters.) 

Fig.  149.  Simple  conoidal  epithelium  of  Lieberkuhn's  follicles.  A.  Transverse  section  of  follicles 
showing  (n)  the  basement-membrane,  the  epithelium,  and  the  inter-foUicular  areolar  tissue,  (&)  cavity 
or  lumen  of  the  follicle  (200  diameters.)  B.  Single  tube  showing  (a)  basement  membrane,  and  (c) 
internal  surface  of  the  wall  of  the  tube  (200  diameters). 

sinuous  fossaB  (mucous  glands)  of  the  cervix  uteri ;  the  male  ure- 
thra and  all  ducts  opening  into  it,  and  the  vas  deferens  to  the  head 
of  the  epididymis.  Its  appearance  in  the  gastric  tubes  is  shown  by 
Fig.  148. 

It  is  also  ciliated  in  all  the  following  parts — the  finest  bronchial 

tubes,  and  all  the  sinuses  (frontal 
and  maxillary),  and  the  cells 
(sphenoidal  and  ethmoidal),  of 
the  face;  on  the  inner  surface  of 
the  membrana  tympani ;  the  up- 
per two-thirds  of  the  cavity  of 
the  uterus,  and  through  the  Fal- 
lopian tubes,  and  the  canals  in 
the  Wolffian  body  in  the  foetus. 
Peculiarities. — The  fact  that 
this  kind  of  epithelium  lines  the  uterine  glands,  is  an  exception  to 
the  law  before  stated,  that  the  ultimate  follicles  of  all  glands  are 
lined  by  simple  scaly  epithelium.  {KUlliher.) 

If  several  of  these  cells  still  cohering,  after  being  detached  from 


Simple  conoidal  epithelium  from  intestinal 
villus  of  a  rabbit,  a,  a.  Membrane  connecting 
the  free  surfaces  of  the  colls,  raised  by  the  action 
of  water. 


EPITHELIUM. 


243 


the  subjacent  membrane,  are  treated  with  water,  they  seem  to  be 
surmounted  by  a  delicate  membrane.  This  is,  however,  merely  a 
continuous  sheet  formed  by  the  ends  of  the  cells ;  they  having  been 
separated  by  the  endosmosis  of  the  water.    (Fig.  150.) 

B.   Compound  Conoidal  Epiihelium. 
This  variety  consists  of  two  or  more  layers  of  cells,  the  outer- 
most being  conoidal.     It  is  shown  by  Figs.  151  and  152.     Where- 
ever  found  it  is  always  ciliated. 


Fig.  151. 


wK^i^Mi  ^i'iWM 


m\mT/F- 


Fig.  151.  Simple  conoidal  ciliated  epithelium,  a.  H'ucleated  cells,  b.  Cilia  and  their  free  extre- 
mities. 

Fig.  152.  Compound  conoidal  ciliated  epithelium  of  nasal  passages,  a.  Superficial  series  of  ciliated 
cells,  b.  Deeper  series  becoming  elongated  vertically,  e.  Various  shapes  of  deepest  ciliated  cells. 
(180  diameters). 

Distribution. — Commencing  about  three-quarters  of  an  inch  within 
the  nostrils,  it  extends  through  the  nasal  passages,  covers  the  upper 
part  of  the  pharynx  and  posterior  surface  of  the  soft  palate;  then 
enters  the  larynx  to  line  that,  the  trachea,  and  the  bronchial  tubes 
to  their  finer  subdivisions.  It  also  lines  the  Eustachian  tube,  and 
the  lachrymal  duct  and  sac. 


Ciliated  Epithelium. 
Epithelium  is  so  called  when  the  outer  layer  of  cells  are  sur- 
mounted by  cilia.  These,  seen  under  the  microscope,  resemble 
very  fine  hairs,  and  the  average  number  attached  to  each  cell  is  10 
to  22.  {^Valentin)  They  grow  from  the  free  (or  outer)  extremity  of 
the  cells,  and  are  generally  so  arranged  as  nearly  to  cover  it,  though 
sometimes  but  a  single  one  is  found.  They  are  fine,  soft  processes 
of  the  cell- membrane,  broader  at  their  base  and  terminating  in  a 
point.  They  are  in  incessant  motion ;  constantly  striking  forward 
from  a  vertical  position  to  ver}''  nearly  a  horizontal  one,  and  in- 
stantly returning  again.  The  author  counted  one  hundred  and 
forty  such  strokes  in  a  minute,  in  case  of  cells  from  the  pharynx  of 


244  THE   TISSUES. 

a  frog.  It  has  been  asserted  that  they  all  strike  toioards  the  outlet  of 
the  passage  on  which  they  are  found;  an  assertion  needing  confir- 
mation however.  The  motion  seems  to  depend  much  upon  the 
state  of  the  cells  in  respect  to  fluidity ;  since  it  will  continue  many 
hours  after  death  (even  78),  in  case  of  man  {OosseUn\  if  the  cells 
are  kept  raoist.^  The  cilia  are  among  the  most  minute  objects  oc- 
curring to  the  histologist;  being  ^g'oo  ^^  ^isi  of  an  inch  long,  and 
not  exceeding  47j,^^(j  to  2^,g^B  of  an  inch  in  diameter.  They  were 
discovered  by  Purkinje  and  Valentin  in  1834.  Figs.  151  and  152 
show  them  on  both  kinds  of  conoidal  epithelium.  (Also  Fig.  91.) 

Distribution. — It  has  been  seen  that  the  ciliated  epithelium  (either 
simple  or  compound  conoidal),  lines  the  whole  extent  of  the  air- 
passages  from  just  within  the  nostrils  to  the  termination  of  the 
finest  bronchial  tubes,  and  the  communicating  cavities  also ;  as  the 
sinuses  and  cells  of  the  face.  Eustachian  tube,  and  membraua  tym- 
pani,  and  the  ductus  ad  nasum  and  lachrymal  sac. 

Further  than  this,  the  ciliated  epithelium  lines  the  upper  two- 
thirds  of  the  cavity  of  the  uterus,  and  the  Fallopian  tubes  through- 
out. The  canals  in  the  Wolffian  bodies  of  the  foetus  must  also  be 
added. 

Peculiarities. — It  is  an  interesting  fact  that  the  epithelium  of  the 
upper  part  of  the  uterus  and  of  the  Fallopian  tubes  is  not  ciliated 
previously  to  puberty. 

Disease  respects  the  distinctions  made  in  regard  to  the  different 
varieties  of  epithelium.  In  croup,  the  nasal  passages  are  almost 
invariably  first  affected,  and  the  disease  follows  the  course  of  the 
ciliated  epithelium  over  the  posterior  surface  of  the  velum,  and 
thence  into  the  larynx  and  trachea,  and  not  along  the  oesophagus 
into  the  stomach.  Again,  a  disease  commencing  in  the  lower  half 
of  the  pharynx,  or  the  tonsils,  does  not  soon  extend  to  the  larynx 
and  trachea,  as  a  general  rule.  Besides,  the  uterine  glands  may  be 
diseased  for  an  indefinite  period  without  the  disease  extending  either 
to  the  uterine  cavity  or  to  the  vagina;  its  conoidal  epithelium  being 
bounded  both  above  and  below  by  the  scaly  variety. 

Development  of  Epithelium. 
The  first  cells  laid  down  to  form  an  epithelium  are  probably  de- 

'  The  motion  of  tlic  cilia  is  destroyed  by  many  chemical  and  mechanical  agents  ; 
and  Vlrchow  has  recently  found  that  a  solution  of  potassa  or  soda  re-excites  it. 
He  infers  from  his  experiments  that  the  substance  of  the  cilia  nearly  approximates 
musculine. 


EPITHELIU^I.  245 

velopcd  according  to  the  method  first  described  (page  120),//'ee  cell- 
development;  they  being  formed  in  a  plasma  exuded  upon  the  base- 
ment-membrane.* They  subsequently  multiply  by  the  fissuraiion 
of  the  cells  and  nuclei  in  the  lower  layers.  They  are  constantly 
growing,  and  on  reaching  maturity,  they  lose  their  vitality  and 
become  detached  or  desquamate.  In  the  mouth  and  alimentary 
canal  they  are  detached  also  by  mechanical  causes. 

The  reparatioyi  of  epithelium  also  takes  place  by  fissuration,  unless 
all  the  layers  of  cells  have  been  removed ;  in  which  case  there  is 
doubtless  a  development  de  novo,  as  at  first.  Sometimes,  however, 
a  long  time  is  required  for  the  formation  of  a  perfect  epithelium; 
as  is  seen  especially  upon  the  surface  of  cicatrices  after  entire  loss 
of  the  skin. 

Fwnctions  of  Epithelium. 
The  functions  of  epithelium  vary  with  the  different  varieties,  and 
also  in  different  parts  of  the  body. 

I.  The  scaly  epithelium  is  specially  for  secretion  aud  protection. 
The  simple  scaly  epithelium  of  serous  membranes,  mucous  folli- 
cles and  glands,  and,  in  part,  of  the  eye  and  the  internal  ear,  and 
the  compound  scaly  epithelium  of  synovial  membranes — are  for 
secretion  of  serous  or  mucous  fluids,  as  the  case  may  be. 

The  simple  scaly  epithelium  of  the  lymphatics  and  bloodvessels, 
of  the  ocular  membranes,  not  alluded  to  in  the  preceding  paragraph, 
and  of  the  Grraafian  vesicle;  the  compound  scaly  epithelium  extend- 
ing from  the  lips  to  the  cardia,  at  the  commencement  of  the  nostrils, 
on  the  lachrymal  ducts,  conjunctiva,  and  tympanic  cavity ;  that 
covering  the  vulva,  vagina,  and  lower  third  of  the  uterine  cavity; 
and  that  lining  the  bladder,  ureters,  pelvis  of  the  kidney  and  female 
urethra — are  for  protection,  and  doubtless  also,  to  some  extent,  for 
secretion. 

The  compound  scaly  epithelium  of  the  skin — the  epidermis — is 
almost  exclusively  protective. 

II.  The  conoiclal  epithelium  is  for  secretion,  absorption,  or  pro- 
tection. 

The  simple  conoidal  epithelium  extending  from  the  cardia,  through 

'  It  has  been  suggested  that  the  fusiform  slender  epithelial  cells  of  the  larger 
arteries  and  some  veins,  are  related  in  their  development  to  the  strijied  lamellae 
which  underlie  them. 


246  THE   TISSUES. 

the  alimentary  canal,  nearly  to  the  anus,  is  both  secretive  (of  mucus) 
and  protective.  The  cells  covering  the  villi  are  also  believed  to  be 
subservient  to  absorption  of  alimentary  materials  into  the  blood. 
Indeed,  epithelium  is  everywhere  remarkably  endosmotic.  In  the 
cervix  uteri  it  is  more  especially  for  secretion;  in  the  excretory 
ducts  of  all  glands,  secretive  and  protective;  as  it  is  also  in  the  male 
urethra  and  all  ducts  opening  into  it,  and  in  the  vas  deferens. 

Ciliated  epithelium  (whether  simple  or  compound  conoidal)  owes 
its  peculiarities  to  its  cilia.  Independently  of  them,  it  may  be,  and 
probably  always  is,  secretive  and  protective.  It  lines  only  the  whole 
of  the  air-passages  (except  the  air-cells),  and  the  passages  opening 
into  them,  and  a  part  of  the  genital  passages  of  the  female.  Its 
peculiar  function,  in  the  former  case,  seems  to  be  to  secure  the  con- 
tact of  new  portions  of  air  in  the  air-passages,  air-cells,  and  others, 
to  subserve  the  function  of  aeration.  The  cilia  may  also  aid  in 
preserving  a  due  state  of  moisture  on  every  part  of  a  membrane, 
or  to  prevent  occlusion  of  narrow  passages  by  a  normal  or  abnor- 
mal secretion — as  in  the  Eustachian  tube,  the  lachrymal  duct  and 
sac,  the  finest  bronchial  tubes,  and  the  Fallopian  tubes. 

It  has  been  suggested  that  the  cilia  on  the  cells  covering  the 
upper  two-thirds  of  the  uterine  cavity,  and  lining  the  Fallopian 
tube,  carry  the  semen  to  the  ovary  to  secure  impregnation;  and  that, 
by  a  reversed  action,  they  also  return  the  impregnated  ovum  to  the 
uterine  cavity,  where  it  remains  to  be  developed  during  the  period 
of  gestation.  Though  this  idea  of  reversed  action  is  purely  hypo- 
thetical, it  is  still  probable  that  the  cilia  have  reference  to  the  func- 
tion of  menstruation  or  impregnation,  or  both,  since  they  are  not 
developed  till  the  period  of  puberty  arrives.  But  it  is  a  gratuitous 
assumption  that  the  cilia  of  the  cavities  in  the  face  (antrum,  &c.)  are 
subservient  to  smell,  since  we  know  that  the  olfactory  nerves  are 
not  distributed  to  these  cavities  at  all. 

Since  secretion  is  in  all  cases  performed  hj  ejnthelial  cells,  all  the 
normal  secretions  contain  them,  or  at  least  their  nuclei  or  their 
debris;  as  has  already  been  seen  in  the  description  of  them  respect- 
ively in  the  Second  Division  of  this  work. 

Epithelium  is  corrugated  and  rendered  opaque  by  the  action  of 
alcohol,  and  hence  the  effect  of  holding  brandy,  &c.,  in  the  mouth. 
In  some  diseases  it  becomes  entirely  detached;  and  thus  is  produced 
the  extreme  redness  of  the  tongue  which  is  so  often  met  with.  An 
irritable  condition  of  the  mucous  membrane  of  course  results  from 


EPITHELIUM. 


247 


its  removal.  Nitrate  of  silver  blackens  the  epidermis  and  renders 
opaque  the  epithelium  of  mucous  membranes,  but  destroys  nothing 
beneath  them.  It  is  therefore  not  a  caustic,  in  any  scientific  sense. 
The  epidermis  is  separated  from  the  corium  by  a  blister,  and  by 
exudations  underneath  it  from  other  causes — as  in  all  vesicular  skin 
diseases. 

Pathological  Conditions  of  Epithelium. 

1.  Epidermic  and  epithelial  tumors  (epithelioma)  are  of  very  fre- 
quent occurrence.  Warts  (verruc£e)  and  callosities  of  the  skin,  espe- 
cially corns  (clavi),  are  minor  instances  of  this  group.  In  the  case 
of  warts,  however,  the  papillas  as  well  as  the  epidermis  become 
hypertrophied.  The  wart-like  iisevi  materni,  ichthyosis,  and  ele- 
phantiasis Arabum,  also  belong  to  this  class,  though  this  last  is  not 
limited  to  the  epidermis  alone. 

2.  Condylomata  (more  properly  termed  impilhmata),  mucous  tu- 
bercles, and  similar  vegetations,  apt  to  form  around  the  orifices  of 
mucous  canals  from  the  irritation  of  syphilitic  or  other  discharges, 
belong  also  to  this  class.    Fig.  153,  b,  shows  one  of  these  vegetations 


Epithelial  new  formations,    a.  Papilloma  highly  magnified,    b.  Epithelial  tumor  from  lip.  {Lebert.) 

as  figured  by  Lebert;  it  being  a  papilla  formed  by  a  layer  of  closely 
imbricated  epithelial  scales,  the  deeper  portions  consisting  of  less 
flattened  cells,  or  nuclei  in  an  amorphous  blastema,  and  extending 
to  the  corium  of  the  skin.  Horns  are  also  epidermic  productions, 
and  sometimes  appear  on  the  human  body.  They  originate  in  the 
sebaceous  follicles,  whose  epithelium,  thrown  off  in  abundance  and 
together  with  fatty  secretion,  forms  a  conical  mass  which  protrudes 
from  the  skin  (usually  of  the  head  or  of  the  forehead),  sometimes 
even  to  the  length  of  six  inches. 

3.  Epithelial  cancer  should  be  distinguished  from  mere  epithe- 
lioma; the  former  being  doubtless  malignant,  though  not  so  certain 
to  affect  the  lymphatic  glands,  and  the  bod}^  generally,  as  the  other 
forms  of  cancer.    It  occurs  on  the  skin  and  mucous  membrane,  the 


248 


THE   TISSUES. 


cheek  and  lips  being  its  most  common  seat.  On  the  skin  it  is  gene- 
rally a  hard,  well-defined  tumor,  irregularly  nodulated,  and  covered 
with  minute  watery  papillae.  On  a  mucous  surface  it  appears  as  a 
cauliflower-like  growth,  more  or  less  red  from  vascular  injection, 
variously  consistent,  and  easily  separated  into  parts  by  pressure.  In 
either  case  the  papillae  and  the  epithelium  covering  them  become 
greatly  hypertrophied ;  the  corium  and  areolar  tissue  also  becoming 

Fig.  154. 


Section  of  epithelial  cancer  of  the  cheek,  a.  Epidermic  scales,  and  fusiform  cells  and  fibres  on 
the  external  surface,  b.  Group  of  epidermic  scales,  c.  Areolar  tissue  of  the  corium.  d.  Cancer- 
cells  in  the  latter  tissue.   (Bennett.) 

converted  into  a  fibroid  substance.    Fig.  15-1  shows  the  microscopic 
structure  of  an  epithelial  cancer  of  the  cheek. 

4.  New  formations  of  epithelium  are  common  in  certain  patholo- 
gical cysts.     A  very  delicate  ciliated  epithelium  has  been  found  on 

Fig.  155. 


Olrlium  albicans,  a.  A  mass  of  epithelial  colls  covered  with  the  granular  matrix  of  the  fungus 
(h),  from  which  a  luxurious  growth  of  niucedinous  filaments  (c)  proceeds. — Magnified  350  diameters. 
(Kolliker.) 


THE   NAILS. 


249 


Fig.  156. 


the  intersaccLilar  partitions  iu  ovarian  tumors,  and  in  those  of  the 
testis.^ 

5.  Some  of  the  peculiar  appearances  of  the  tongue  in  disease  are 
due  to  changes  in  its  epithelial  cells.  They  may  even  become  a 
nidus  for  the  development  of  parasitic  vegetation ;  of  which  the  pe- 
culiar white  coat  produced  by  the  oidium  albicans  (Fig.  155)  in  some 
cases  of  diphtheritis,  is  an  illustration. 

SECTION   II. 
THE   NAILS. 

Nails  are  merely  a  modification  of  the  epidermis,  being  histolo- 
gically a  very  much  condensed  compound  scaly  epithelium.  (Fig. 
156.)  They  are  also,  by  maceration, 
detached  in  continuity  with  it.  And, 
according  to  Mulder's  investigations, 
they  differ  from  epidermis  in  chemi- 
cal composition,  only  in  containing  a 
larger  proportion  of  sulphur  and  car- 
bon. 

The  surface  covered  by  the  nail, 
and  upon  which  it  is  developed,  is 
called  the  heel  of  the  nail.  A  trans- 
verse section  of  it,  and  of  the  nail 
also,  is  seen  in  Fig.  157.  It  presents 
a  series  of  peculiar  ridges  on  its  sur- 
face, beginning  under  the  root  of  the 
nail,  and  at  first  radiating  outwards 
from  the  centre  for  a  distance  of  2-| 
to  3|  lines;  whence  they  become  pa- 
rallel and  more  prominent,  and  take 

Fig.  157. 

.7  .f 


Transverse  section  of  nail  and  its  matrix. 
A.  Skin.  B.  Stratum  MalpigWi  of  nail.  c. 
Horny  layer  of  same.  a.  Papillae  of  nail- 
matrix,  h.  Cells  of  the  Malpighian  stra- 
tum, e.  Eidges  of  horny  substance  of  nail. 
d.  Deepest  layer  of  perpendicular  cells  of 
Malpighian  layer,  e.  Upper  layer  of  flat- 
tened cells  of  the  same.  /.  Nuclei  of  the 
true  naU  substance. 


Body  and  bed  of  nail,  transverse  section,  a.  Bed  of  nail,  with  its  ridges,  h.  Corium  of  lateral 
portion  uf  wall  of  the  nail.  c.  Stratum  Malpighii,  with  its  ridges  (white),  d.  Papilla;,  e.  Cuticle  of 
wall  of  tho  nail.  /.  Horny  layer  of  nail,  with  short  notches  on  its  under  surface.— Magnified  8 
diameters.  {Kidliker.) 

'  London  Lancet,  Sept.  1856. 


250 


THE   TISSUES. 


on  tlie  form  of  true  lamina,  g^^  ^^  t2o  ^^  ^^  ^^^^  deep.  The  line 
of  transition  of  the  ridges  into  the  laminoe  divides  the  bed  of  the 
nail  into  two  sections,  differing  in  color  and  in  extent;  the  posterior 
smaller  one  underlying  its  root  and  lunula^  and  the  other  portion  its 
body.  The  ridges  and  laminas  number  from  fifty  to  ninety.  At 
their  edges  they  are  beset  with  a  series  of  short  papilla.  On  the 
little  toe,  however,  the  papilla  are  frequently  not  seated  upon  the 
ridges,  but  are  dispersed.    {KoUiker.) 

The  ivall  of  the  nail  is  the  process  of  the  skin  continuous  with 
the  bed  of  the  nail,  laterally  and  posteriorly ;  forming  the  folds  on 
the  sides,  by  which  the  nail  is  limited.  The  corium  of  the  wall  and 
of  the  bed  of  the  nail  contains  but  little  fat ;  but  in  the  ridges  and 
the  laminie  is  an  abundance  of  fine  elastic  fibres.  The  capillaries, 
iiVu  ^^  Ts'oo  ^^  ^^  ^^^^  ^^  diameter,  form  simple  loops  in  the  pa- 
pillee;  and  the  nerves  have  the  same  relation  as  in  the  skin. 

The  nail  itself  is  divided  into  the  body,  the  root,  and  the  free 
edge.     These  are  shown  by  Fig.  158.     The  lunula  is  the  opaque 

semilunar  portion  of  the  nail  (not  seen 
in  all  cases),  at  its  posterior  part.  When 
not  apparent,  it  is  covered  entirely  by 
the  fold  of  the  skin  underneath  which 
the  root  of  the  nail  lies,  and  which  is 
called  the  matrix  of  the  nail. 

The  lower  surface  of  the  nail  corre- 
sponds with  the  surface  of  the  ridges  and 
laminre  of  the  bed.  Furrows  and  ridges 
therefore  appear  on  the  former  as  upon 
the  latter.  It  is  by  the  mutual  interlock- 
ing of  these  opposite  surfaces  that  the 
intimate  union  of  the  nail  with  the  co- 
rium of  the  skin  is  effected.  (Fig.  157.) 

In  structure,  the  nails,  like  the  epithelium  of  the  skin,  consist  of 
two  layers;  the  deeper  being  soft  (the  Malpighian  layer,  sometimes 
improperly  called  the  stratum  mucoszim),  and  the  superficial,  consti- 
tuting most  of  the  thickness  of  the  nail  (the  horny  layer).  This 
stratum  consists  wholly  of  cells,  like  that  of  the  epidermis  (except 
that  they  are  nucleated) ;  and  in  the  negro  is  black.  Hassall  states 
that  the  younger  cells  of  this  layer  generally  contain  pigment  in 
the  white  races.  The  horny  layer  is  quite  smooth  on  its  under  sur- 
face at  the  root,  but  becomes  ridged  further  forwards;  the  ridges 


Relations  of  nail  to  the  cuticle,  n,  n. 
Cuticle  and  nail;  m,  m.  Corium  and 
bed  of  nail. 


THE   NAILS.  251 

appearing  in  transverse  sections  as  pointed  processes,  -j-j'^^  to  gj^ 
of  an  inch  in  length,  and  even  ^J^  to  ^hs  of  an  inch  at  the  edge  of 
the  nail.  The  upper  surface  also  frequently  shows  distinct  parallel 
longitudinal  streaks,  appearing  as  the  almost  effaced  impressions  of 
the  laminae  below. 

The  nail  increases  in  thickness  from  the  root  to  near  the  free 
edge,  being  at  least  three  times  as  thick  anteriorly  as  posteriorly 
(4'u  to  -STi  of  an  inch). 

Unprepared  sections  of  nails  give  very  little  indication  of  any 
structure  whatever.  But  on  boiling  them  in  dilute  caustic  soda,  they 
at  once  display  a  beautiful  arrangement  of  cells,  like  a  scaly  epi- 
thelium, but  nucleated;  these  being  flatter  in  the  superficial  than 
in  the  deeper  layer,  and  not  more  than  one  half  as  thick.  One  or 
several  layers  of  these  cells  constitute  a  lamella;  and  the  lamellae 
closely  united  and  not  sharply  defined,  form  the  whole  of  the  horny 
substance.  The  greater  hardness  of  nails  as  compared  with  epi- 
dermis, is  said  by  Lauth  to  be  due  to  a  greater  proportional  amount 
of  phosphate  of  lime  in  the  former. 

The  nails  continue  to  grow  only  so  long  as  they  are  cut,  Ee- 
maining  uncut,  they  attain  to  the  length  of  one  and  a  half  to  two 
inches,  and  curve  over  the  ends  of  the  fingers  and  toes.  Among 
the  Chinese,  of  whom  the  literary  class  never  cut  the  nails,  the 
length  is,  according  to  Hamilton,  two  inches.  The  groAVth  takes 
place  at  the  expense  of  the  cells  in  the  Malpighian  layer,  both  at  the 
edge  of  the  root  and  under  the  body  of  the  nail.  Thus,  the  latter 
becomes  longer  and  thicker  at  the  same  time.  The  longitudinal 
growth  is,  however,  by  far  the  most  rapid ;  since  the  first  round 
cells  become  more  and  more  flattened  and  elongated  as  they  move 
forwards  and  upwards  from  their  first  position. 

The  time  necessary  for  a  nail  to  grow  its  whole  length,  varies  in 
different  parts  from  twelve  to  twenty  or  more  weeks ;  and  hence 
this  length  of  time  is  required  for  the  formation  of  a  new  nail,^ 
The  nail  is  thicker  on  its  most  convex  portion  than  at  its  edges. 

If  the  changes  in  the  nail  cells  are  investigated  as  compared  with 
those  of  the  epidermis,  a  striking  similarity  is  discovered.  1,  The 
original  cell-membranes  (those  of  the  Malpighian  layer)  become 

'  According  to  M,  Beau,  the  nails  of  the  fingers  grow  four  times  as  rapidly  as 
those  of  the  toes  ;  the  thumb  growing  two-fifths  of  a  line  per  week,  and  its  whole 
length  in  twenty  weeks — while  the  nail  of  the  grgat  toe  requires  ninety-six  weeks, 
or  nearly  two  years,  to  grow  its  length.  The  portion  of  a  nail  growing  during  a 
disease  is  thinner  than  the  rest,  as  is  shown  by  a  transverse  groove  or  depression 


252  THE   TISSUES. 

harder,  and  more  phospliate  of  lime  is  deposited  in  tliem  or  witliin 
the  cells.  2.  Like  the  horny  cells  of  the  epidermis,  they  become 
flattened  and  increase  longitudinally  and  transversely.  3.  They 
coalesce  more  completely,  so  that  they  cannot  be  separately  recog- 
nized. But  their  nuclei  do  not  disappear  as  do  those  of  the  epider- 
mis; and  herein  is  a  characteristic  distinction. 

The  nails  are  constantly  suffering  loss  from  friction  and  other 
causes.  Much  of  the  matter  accumulating  under  them  consists  of 
epithelial  cells. 

The  developmerit  of  the  nails  commences  in  the  third  month  of 
intra-uterine  life ;  they  not  being  at  first  distinguishable  from  a  soft 
epidermis.  The  ridges  of  the  bed  of  the  nail  are  well  marked  at 
the  end  of  the  fourth  month.  They  cover  the  whole  bed,  and  have 
assumed  the  consistency  of  a  nail  at  five  months,  and  reach  the 
extremities  of  the  finger  at  eight  months. 

The  free  edge  of  the  nail  of  the  new-born  infant  is  cast  off  once 
at  least  (Weber  says  many  times),  soon  after  birth;  probably  from 
external  violence  which  it  is  too  delicate  to  resist.  This  free  edge 
appears  to  be  a  nail  of  an  earlier  period,  probably  of  about  the 
sixth  month,  which  has  been  thrust  forward  in  the  course  of  deve- 
lopment. Six  or  seven  months  after  birth  the  first  set  of  nails  is 
completely  replaced  by  new  ones  [Kolliker) ;  and  at  two  or  three 
years  the  horny  layer  is  not  distinguishable  in  appearance  from  that 
of  the  adult. 

Nails,  when  destroyed,  are  almost  always  imperfectly  regenerated, 
on  account  of  injury  done  to  the  laminae  and  vessels.  A  rudi- 
mentary nail  sometimes  appears  on  the  second  phalanx  of  a  finger 
in  case  of  loss  of  the  first.  In  some  rare  cases,  a  periodical  loss 
and  regeneration  of  the  nails  occurs. 

The  hoofs  and  claws  of  the  lower  animals  are  the  analogues  of 
the  nails,  both  physiologically  and  histologically. 

Uses  of  the  Nails. — The  nails  support  the  pulp  of  the  fingers  and 
toes,  and  thus  conduce  to  the  perfection  of  touch.  They  also  in- 
crease the  power  of  the  fingers  as  prehensile  organs ;  and  in  a  state 
of  nature  at  least,  {i.  e.  if  remaining  uncut),  they  become  not  ineffi- 
cient means  of  attack  and  defence. 

Pathological  States  of  the  Nails. 

Any  abnormal  condition  of  the  bed  of  the  nail  will,  of  course, 
affect  the  growth  of  the  latter.  In  the  lamellated  nails  of  old  peo- 
ple, Kcilliker  found  all  the  capillaries  in  the  anterior  segment  of  the 


THE   HAIR, 


253 


bed  closely  filled  with  fat-granules  of  various  sizes.  It  is  an  inte- 
resting fact,  and  not  well  explained,  that  the  nails  become  deformed 
(curved  toward  the  free  edge),  in  phthisis  and  cyanosis.  In  the 
rabbit,  it  was  found  by  Steinrlick  that  the  division  of  the  ischiatic 
nerve  caused  the  nails  and  hair  to  fall  ofl'. 


SECTION  III. 


THE    HAIK. 


Fig.  159. 


Each  hair  consists  of  its  shaft  {scajpus),  and  the  root ;  the  former 
including  all  that  projects  free  from  the  surface  of  the  skin ;  the 
latter,  the  portion  beneath  the  surface. 
(Fig.  159.)  The  bulb  is  the  deepest 
portion  of  the  root,  and  is  from  1|  to 
3  times  the  diameter  of  the  shaft. 

A.  The  shaft  in  straight  hairs  is 
rounded  and  straight;  undulated  and 
flattened  in  the  wavy;  and  spirally 
twisted  and  flat,  or  slightly  ribbed,  in 
curly  and  woolly  hairs.  It  consists  of 
1,  the  cortical  or  fibrous  substance,  2, 
the  cuticle,  and  3,  the  medulla,  which 
is,  however,  often  absent. 

1.  The  fibrous  substance,  which  cui.- 
stitutes  the  greater  part  of  the  bulk  of 
the  hair,  is  striated  longitudinally, 
streaked  or  spotted,  and  more  or  less 
colored,  except  in  white  hairs,  in  which 
it  is  transparent.  The  color  is  some- 
times pretty  regularly  distributed 
through  its  whole  substance ;  at  others, 
concentrated  in  a  few  elongated  granu- 
lar spots.  By  the  action  of  hot  con- 
centrated sulphuric  acid,  the  fibrous 
portion  of  the  hair  is  shown  to  be 
made  up  of  flat,  elongated  fibres  of 
various  breadths  (go'oo  ^^  24'uo  of  an 
inch),  of  marked  rigidity  and  brittle- 
ness,  and  with  notched  margins  and 
ends.  In  dark  hairs,  they  have  a  dark 
tinge;    in   pale   ones   they  are   clear. 


structure  of  hair.  a.  The  shaft.  6. 
Koot.  c.  Bulb.  d.  Epidermis,  e.  Inner 
root-sheath,  g.  Basement-membrane  of 
hair-sac.  h.  Transverse  and  longitudi- 
nal fibrous  layer  of  the  sac.  i.  Papilla. 
li.  Excretory  duct  of  sebaceous  glands, 
■n-ith  epithelium.  I.  Cerium  at  the  aper- 
ture of  the  sac.  m.  Stratum  Malpighii  of 
the  skin.  7i.  Cuticle  of  do.  somewhat  re- 
mi  n-\  ,1  ^1  -,,.      tracted  into  the  sac.   o.  Outer  root-sheath. 

These  fibres  are  not,  however,  the  ulti-  -Magnified  ooo  diameters,  {mmer.) 


254 


THE   TISSUES. 


mate  elements  of  the  fibrous  substance;  eacli  of  them  consistino-  of 
an  aggregation  of  flat  fusiform  fibre-cells  or  plates — the  plates  of  the 


fibrous  substance — 
inch  broad,  and 


_i  _ 

5  00 


to  3^3  of  an  inch  long, 


scoo 


to 


of  an 


to  T-g'oo  of  an  inch  thick,  with  uneven  sur- 


faces and  irregular  edg-es. 


Fig.  160. 


They  very  frequently  exhibit  a  darker 
streak  in  the  interior,  and 
sometimes  contain  granular 
pigment.  In  other  respects, 
they  are  homogeneous,  and 
present  no  minuter  elements. 
(Fig.  160.) 

The  dark  spots,  dots,  and 
streaks  of  the  fibrous  portion 
are  of  three  kinds:  1,  granu- 
lar pigment ;  2,  cavities  filled 
with  air  or  fluid;  3,  nuclei. 
The  pigment  granules  are  de- 
posited in  the  plates  of  the 
hair,  are  especially  abundant 
in  dark  hairs,  and  vary  much 
in  their  size  and  form.  The 
cavities  filled  with  air  appear 
in   the  form  of  round  dots; 


3  OOU(J 


to  i6onu  of  an  inch  in 


1      of 
^°d  ^^^^5  to  750^^ 


Plates,  or  flbro-cells  of  fibrous  substance  of  the  hair, 
treated  with  acetic  acid.  A.  Isolated  plates.  1.  From 
the  surface  (3  single,  2  united.)  2.  From  the  side.  B. 
A  lamella  composed  of  many  such  plates. — Magnified 
300  diameters.  (KoUiker.) 


ties  of  the  pigment  spots,  and  are  y^j'^o  to  t^-Jjj  of  an  inch 


diameter;  or  of  longish  streaks 
an  inch  in  length, 
of  an  inch 
in  breadth,  running  parallel 
with  the  axis  of  the  hair. 
They  are  most  frequent  in 
white  hairs,  and  often  occur 
in  fair,  bright  brown,  and 
bright  red  hairs,  in  great 
numbers.  They  are  absent 
in  very  dark  hairs,  and  in  the 
root  of  all  hairs.  The  nuclei 
are,  in  dark  hairs,  commonly 
connected  with  the  extremi- 

by 


long, 


THE   HAIR,  255 

2700TJ  *o  T(j'ciT)?5  ^^  ^^  ^^^^^  wiclc.  Very  similar  appearances  are,  bow- 
ever,  sometimes  produced  by  the  boundary  lines  of  the  hair-plates. 

This  description  of  the  fibrous  substance  of  the  shaft  applies 
also  to  that  portion  of  the  root  which  is  solid  and  brittle.  In  the 
deeper  and  softer  portions,  the  hair-plates  are  less  rigid  and  have 
the  form  of  more  or  less  elongated  cells  with  cylindrical,  straight, 
or  serpentine  nuclei,  easily  rendered  apparent  by  acetic  acid.  Fi- 
nally, in  the  bulb  they  are  merely  round  cells  4^'g^  to  5  ^^55  of  an 
inch  in  diameter ;  closely  packed  together,  and,  like  the  Malpighian 
layer  of  the  epidermis,  sometimes  containing  colorless  granules,  and 
sometimes  so  full  of  coloredfones  as  to  constitute  true  pigment-cells 
in  appearance. 

The  color  of  the  fibrous  portion  of  the  hair  is  due  partly  to 
granules  of  pigment,  to  some  extent  to  the  air-cavities,  and  partly 
to  a  pigment  blended  with  the  substance  of  the  hair-plates.  The 
granule-pigment  presents  all  shades,  from  clear  yellow  through 
red  and  brown  to  black.  The  last  mentioned,  or  diffused  pigment, 
is  quite  absent  in  white  hairs,  and  is  scanty  in  clear  fair  hairs.  It 
is  most  abundant  in  the  more  opaque  fair  hairs,  and  in  red  as  well  as 
in  dark  hairs;  it  alone  sometimes  producing  an  intense  red  or  brown 
color.  These  two  pigments  vary  in  their  proportion ;  but  are  about 
equal  in  very  light  and  in  very  dark  hairs. 

2.  The  cuticle  of  the  hair  is  a  very  thin,  transparent  pellicle  in- 
vesting the  hair,  and  in  intimate  union  with  the  fibrous  substance. 
It  consists  of  but  a  single  layer,  composed  of  plates  arranged  like 
tiles;  and  is  g^'^o  to  ^^'^^  of  an  inch  thick.  Each  plate  is  5J0  to 
4  25  of  an  inch  in  the  transverse  direction  of  the  hair,  and  7^^  to 
gJ,-Q  in  that  of  its  length  (Fig.  161,  d,  d')\  and  is  only  about  540^0 
of  an  inch  thick.  On  the  lower  part  of  the  root^  however,  there 
are  two  layers  of  epidermis.  (Fig.  162,  c,  d)  The  cells  of  the  outer 
layer  are  thicker  than  those  of  the  inner,  its  whole  thickness  here 
being  ^-^^-^  to  q-^^-q  of  an  inch;  while  the  inner  is  ^^'^^  to  gJ^^j  of 
an  inch  thick.  Kolliker  states  that  the  two  layers  of  epidermis  pass 
into  the  outer  nucleated  cells  of  the  bulb. 

3.  The  medidlary  suhsiance  varies  most  of  all  of  the  constituents 
of  the  hair.  It  is  a  cord  extending  in  the  axis  of  the  hair  from 
near  the  bulb  almost  to  the  point.  It  is  usually  present  in  the  thick, 
short  hairs,  and  the  stronger  long  ones,  and  the  white  hairs  of  the 
head;  and  absent  in  the  down  [lanugo)  and  the  colored  hairs  of  the 
head.   It  consists  of  from  one  to  five  columns  of  superimposed  cells, 


256 


THE   TISSUES. 


rectangular  or  quadrangular,  and  rarely  rounded  or  fusiform,  y^Vo 
to  YsVo  of  ^'^  i^ch  in  diameter,  containing  dark,  fat-like  granules, 
and  a  clear  nucleus,  ^^Vo  to  goVo  of  an  inch  in  diameter.  The 
granules  are,  however,  not  fat  nor  pigment,  but  merely  air-vesicles. 


Fig.  161. 


Fig.  162. 


^^    S  7)< 


Fig.  161.  Plates  of  cuticle  of  hair,  &c.  a,  b.  Transverse  sections  with  and  without  pigment  in  tlie 
centra  e.  A  longitudinal  section  showing  imhrication,  and  the  pigment  in  the  fibrous  portion,  d. 
Cortical  plates  showing  edges,   d'.  Margin  of  same,  showing  their  imbrication.  (Magn.  150  diameters.) 

Fig.  162.  Hair-bulb,  root-sheath,  its  epidermis,  &c.  a.  Medulla  containing  air-cavities  and  indis- 
tinct cells.  6.  Fibrous  substance,  e,  d.  Inner  and  outer  layers  of  cuticle.  e,f.  Inner  and  outer 
layers  of  internal  root-sheath,  ff.  External  root-sheath,  h.  Basement  membrane,  i.  Transverse 
fibre-stratum,  k.  Longitudinal  fibre-stratum.  I.  Papilla,  ra.  Lowest  cells  of  hair-bulb  continuous 
with  those  of  external  root-sheath,  n.  Perpendicularly  placed  nucleated  cells,  becoming  non-nucle- 
ated near  p,  and  continuous  with  the  inner  layer  of  the  cuticle,  o.  Small  perpendicularly  arranged 
nucleated  cells  passing  into  the  outer  layer  of  the  cuticle.  J7.  Lowest  portion  of  the  inner  root-sheath. 
q.  Union  of  cuticle  with  fibrous  substance,  r.  Commencement  of  the  medulla  in  colorless  cells,  s. 
Part  where  the  cells  of  the  bulb  begin  to  lengthen,  to  form  the  fusiform  plates  and  cells  of  the  shaft. 

They  vary,  according  to  the  hairs,  from  sooiro  to  goVif  of  an  inch 
in  diameter,  and  occupy  the  medullary  cells  in  great  amount,  exist- 
ing both  in  white  and  in  dark  hairs.  In  the  latter  the  air  appears 
of  a  brown-red  or  brown  tinge,  from  being  seen  through  the  colored 
fibrous  substance ;  in  white  hairs  it  is  of  a  silver  white.  It  appears 
certain  that  the  air  may  pass  from  one  air-vesicle  to  another  in  the 
hair.  Just  above  the  bulb,  and  sometimes  also  in  spots  in  the  shaft, 
there  are  some  of  these  air- vesicles,  and  therefore  a  paleness  results. 
In  some  hairs,  especially  the  red,  there  is  often  no  definite  line  of 
demarcation  between  the  fibrous  portion  and  the  medulla. 

The  medulla  usually  constitutes  from  one-fifth  to  one-third  of  the 


THE   HAIR. 


257 


Cells  of  medulla  of  Rodentia,  &c.  A.  Hair  of 
musk-deer,  formed  almost  entirely  of  polygonal 
cells.  B.  Hair  of  sable,  showing  large  rounded 
cells  in  the  interior,  covered  by  imbricated  scales 
or  flattened  cells. 

Fig.  164. 


whole  diameter  of  tlie  liair ;  being  both  relatively  and  absolutely 
thickest  in  short,  thick  hairs,  and  thinnest  in  the  lanugo  and  the 
hairs  of  the  head.      It  presents 

a  rounded  or  flattened  figure  in  a  b 

transverse  sections.  (Figs.  161,  a, 
and  103.)  Very  rarely  the  me- 
dulla is  double  throughout;  but 
it  is  more  frequently  divided  for 
a  distance  into  two  trunks,  which 
soon  unite  again.  In  the  Ro- 
dentia (beaver,  squirrel,  &c.)  the 
medulla  is  divided  by  dissepi- 
ments ;  in  the  musk-deer  it  con- 
stitutes the  entire  hair,  except  a 
very  thin  cuticle,  and  in  the  sable 
its  cells  are  very  large.  (Fig.  163.) 
The  hair  of  the  bat  and  the 
squirrel  is  shown  by  Fig.  164. 

B.  The  hair-sacs  are  flask-like 
follicles,  Y2  0  to  4V  of  an  inch  long, 
extending  into  the  upper  layers 
only  of  the  corium  in  case  of 
the  finest  hairs ;  about  one-half 
through  it  in  case  of  those  of 
medium  size  ;  and  even  throus-li 
to  the  subcutaneous  areolar  tissue 
in  case  of  the  longest  and  strong- 
est (the  whiskers,  on  the  head, 
pubes,  and  axillae).  They  are 
merely  involutions  of  the  skin, 
at  the  bottom  of  which  the  'hoAV-papilla  is  situated.  They  have  there- 
fore an  internal  epithelium  or  root-sheath,  and  an  external  or  fibrous 
layer;  the  latter  being  continuous  with  the  corium,  and  the  former 
with  the  epidermis.    (Fig.  162,  i,  /c,  and  e,/,  g) 

The  root-sheath,  or  the  epidermic  investment  of  the  hair-sac,  is 
continuous  with  the  epidermis  around  the  aperture  of  the  sac,  and 
consists  of  two  layers,  an  internal  and  an  external.  The  external  rooi- 
sheath  {rj)  is  continuous  with  the  Malpighian  layer  (rete  mucosum) 
of  the  skin,  and  rests  on  a  distinct  basement  membrane;  which,  how- 
ever, cannot  be  demonstrated  between  this  and  the  internal  fibrous 
17 


Small  hair  of  squirrel,     b.  Large  hair  of  .■squir- 
rel,   c.  Hair  of  India  bat. 


258 


THE  TISSUES. 


layer  of  the  liair-sac,  except  on  the  lower  half  of  the  sac.  At  the 
bottom  of  the  latter,  the  cells  of  this  layer  pass  gradually  into  the 
round  cells  Avhich  cover  the  papilla.  It  is  generally  three  to  five 
times  as  thick  as  the  inner  layer;  containing  from  five  to  twelve 
layers  of  cells,  and  terminating  below  in  a  very  thin  lamella. 

The  inner  root-sheath  (Fig.  162,  e,/)  is  a  transparent  membrane, 
extending  from  the  bottom  of  the  hair-sac  over  more  than  two- 
thirds  of  it.  It  is  connected  externally  with  the  external  layer  just 
described  {g\  and  internally  with  the  cuticle  of  the  hair;  being,  in 
fact,  blended  with  the  latter  (c,  d).  It  is  very  dense  and  elastic,  and 
consists,  except  in  its  lowermost  part,  of  two  or  three  layers  of  poly- 
gonal, elongated,  transparent,  and  somewhat  yellowish  cells,  with 
their  longitudinal  axes  parallel  to  that  of  the  hair.  The  cells  form- 
ing the  outermost  layer  of  the  two  (or  three),  and  which  alone  was 
formerly  known,  are  elongated  and  without  nuclei.  Those  of  the 
innermost  layer  (Huxley's  layer)  are  also  polygonal,  but  shorter 
and  broader,  and  always  (in  the  lower  half,  at  least,  of  the  root- 

Fis.  165. 


Cells,  &c.,  of  inner  root-sheath,  a.  From  its  outer  layor:  1,  its  isolated  plates;  2,  the  same  in 
connection  after  the  action  of  caustic  soda  ;  a,  apertures  between  tlie  cells  6.  B.  Cells  from  the  inner 
layer,  with  elongated  and  slightly  notched  nuclei,  c.  Nucleated  cells  of  the  lowest  part  (single 
layer)  of  the  inner  sheath. — Magnified  S.JO  diameters.  [KHUiker.) 

sheath)  possessed  of  distinct  elongated  nuclei.  (Fig.  165.)  This 
layer,  however,  also  blends  with  the  cells  of  the  hair-bulb,  like  the 
exterior.  (Fig.  162,  m) 

Finally,  the  papilla  of  the  hair  (/)  belongs  to  the  sac,  and  corre- 


THE    IIAIK.  259 

spends  to  a  papilla  of  the  skiu.  It  is  ovate  or  fungiform,  Tj'g  to  ^^75 
of  an  incli  long,  yJ^  to  -c,\^  of  an  inch  broad,  and  is  connected  with 
tlie  fibrous  tissue  of  the  sac  by  a  pedicle.  Its  surface  is  perfectly 
smooth,  and  it  consists,  like  the  cutaneous  papilla3,  of  an  indistinctly 
fibrous  tissue,  with  scattered  nuclei  and  granules,  but  no  cells.  Nei- 
ther Hassall,  Giinther,  nor  Kcilliker  has  found,  in  it  either  vessels 
or  nerves.  In  some  animals,  however,  the  vessels  may  easily  be 
seen;  and  we  must  not  yet  positively  infer  that  they  do  not  exist 
in  the  papillas  of  human  hairs  also. 

Chemical  Composition  of  Hair. 

This  subject  is  still  not  sufficiently  understood;  but  the  hairs  are 
chiefly  composed  of  a  nitrogenized  substance  (keratine),  soluble  in 
alkalies,  and  insoluble  in  boiling  acetic  acid.  Mulder  considers  that 
10  per  cent,  of  sulphamide  is  combined  with  this  nitrogenized  com- 
pound. Scherer  finds  10  per  cent,  of  the  hairs  to  be  sulphur.  Hairs 
also  contain  a  considerable  amount  of  dark  or  clear  fatty  matter. 
Chemical  analysis  does  not  discover  any  special  pigment,  though 
the  microscope  does,  as  has  been  seen  (p.  255), 

The  ash  of  hair  amounts  to  1  to  2  per  cent.,  in  which  are  found 
oxide  of  iron  (more  in  dark  hair),  oxide  of  manganese,  and  traces- 
of  silica.  Jahn  found  phosphate  of  magnesia  and  sulphate  of  alu- 
mina in  white  hairs ;  and  copper  occurs  in  the  greenish  hairs  of 
those  who  work  in  copper  and  brass.  (Langm.) 

Hairs  withstand  putrefaction  better  than  any  other  part  of  the- 
organism.  Even  those  of  mummies  are  found  to  be  quite  un- 
changed. Hence,  also,  the  hair  is  preserved  as  a  cherished  relic  of 
the  departed.  Metallic  oxides  color  it  as  they  do  the  epidermis. 
Hence  the  salts  of  silver  and  manganese  blacken  the  hair,  a  sul- 
phuret  of  these  metals  being  produced.  Chlorine  bleaches  it  after 
prolonged  action. 

Wool  and  bristles  do  not  differ  essentially  in  composition  from 
hair.  Scherer  finds,  however,  that  feathers  differ  much  from  the 
other  horny  tissues,  and  especially  from  hair.  Gorup-Besanez  found 
a  considerable  cjuantity  of  silica  in  feathers. 

Physical  Properties  of  Hair. 

The  hairs  are  quite  elastic.     They  stretch,  without  breaking,  to 

nearly  one-third  more  than  their  original  length ;  and  if  stretched 

only  one-fifth,  they  contract  again  so  perfectly  that  they  permanently 

remain  only  •j','  longer  than  at  first.  {Weher)     Still,  their  strength 


260  THE   TISSUES. 

is  great,  though  so  extensible.  A  hair  of  the  head  will  support  at 
least  six  ounces  without  breakino;. 

The  hairs  readily  imbibe  water,  and  as  readily  give  it  out  again ; 
hence  they  are  sometimes  dry  and  brittle,  and  sometimes  moist  and 
soft,  according  to  the  amount  of  moisture  the  skin  or  the  atmo- 
sphere contains.  They  are  also  longer  or  shorter,  in  proportion  as 
they  contain  more  or  less  moisture ;  and  hence  their  use  in  hy- 
grometry. 

The  hairs  become  slowly  colored  during  their  development;  being 
quite  colorless  in  the  embryo,  and  paler  in  youth  generally  than  in 
middle  age.  In  the  adult,  the  palest  are  the  downy  hairs  which 
have  remained,  as  it  were,  in  the  foetal  condition ;  while  the  longer 
ones  are  always  darker,  and  the  darkest  of  all  are  those  of  the 
head,  beard,  and  pubes. 

The  durability  of  the  hair  results  from  its  indestructibility  by 
external  agents,  before  alluded  to.  False  hair  may  be  continually 
worn  for  many  years. 

Distribution  and  Size  of  the  Hairs. 

The  hairs  are  distributed  over  every  part  of  the  surface  of  the 
human  body,  except  the  palm  of  the  hand  and  the  sole  of  the  foot, 
the  dorsum  of  the  last  joint  of  the  fingers  and  toes,  the  inner  sur- 
face of  the  prepuce,  the  glans  penis,  the  upper  eyelids,  and  the  lips. 
They  present  differences  in  size  and  number  in  different  regions ; 
and  also  according  to  age,  sex,  race,  and  individual  peculiarities. 

In  size,  three  varieties  may  be  mentioned  {Kolliker) :  1.  Long, 
soft  hairs,  1  to  3  feet  and  more  in  length,  and  g^^  to  j^o  of  an  inch 
in  thickness ;  2.  Short,  stiff",  thick  hairs,  |-  to  I  of  an  inch  in  length, 
and  4^^  to  j^^  of  an  inch  thick;  8.  Short  and  very  fine  hairs  or 
down  {lanugo),  j'^  to  ^  of  an  inch  long,  and  ^-^jsxs  to  y^Vo  thick. 
The  first  includes  the  hairs  of  the  head,  beard,  &c. ;  the  second,  those 
of  the  nostrils  (vibrissae),  the  eyelashes  (cilia),  and  those  in  the  ex- 
ternal auditory  passage;  the  last  includes  the  hairs  on  the  face  gene- 
rally, on  the  trunk  and  extremities,  on  the  caruncula  lachrymalis, 
and  those  (often  absent)  of  the  labia  minora.  (Kenle.)  Other  things 
being  equal,  black  hairs  are  the  coarsest,  and  blonde  the  finest. 

On  the  heads  of  females,  the  length  of  the  hairs  has  sometimes 
equalled  that  of  the  whole  body,  and  the  coarsest  hairs  are  also 
found  on  women.  (  Wilson.)  Beards  also  not  seldom  reach  down  to 
the  waist. 

The  hairs  are  not  true  cylinders,  as  usually  supposed,  but  present 


THE  nAIR.  261 

an  oval  section,  or  some  form  differing  still  more  from  circular. 
(Fig.  161,  a,  h.)  Those  of  the  scalp  are  the  most  nearly  cylindrical 
in  form. — Nor  are  they  of  cf[ual  diameter  throughout;  but  fusiform 
rather,  and  usually  terminating  in  a  very  acute  point.  Indeed, 
hairs  cut  off  transversely,  become  pointed  again  in  a  short  time; 
apparently  by  the  wearing  away  of  the  more  external  portions  of 
the  fibrous  substance. 

The  number  of  hairs  upon  a  given  extent  of  surface  varies  with 
their  color  and  the  particular  part  of  the  body.  On  the  same  ex- 
tent of  surface,  Withof  found  147  black  hairs,  162  brown,  and  182 
blonde.  On  a  surface  one-fourth  of  an  inch  square,  he  found  in 
case  of  a  moderately  hairy  man,  293  hairs  upon  the  scalp,  39  on 
the  chin,  3-1  on  the  pubes,  23  on  the  forearm,  19  on  the  outer  mar- 
gin of  the  back  of  the  hand,  and  13  on  the  anterior  surface  of  the 
leg.  In  men,  closely  set  hairs  not  unfrequently  occur  on  the  chest, 
shoulders,  and  extremities.  At  the  period  of  puberty,  a  sudden 
development  occurs  in  both  sexes  upon  the  pubes  and  axillse ;  and 
in  males  on  the  chin,  cheeks,  abdomen,  and  chest  also.  In  a  very 
hairy  man,  mentioned  by  Wilson,^  52  hairs  were  found  on  a  certain 
surface  on  the  chin,  and  45  on  the  pubes.  Being  married  soon 
after,  there  were  found,  at  the  end  of  four  years,  59  on  the  chin  and 
50  on  the  pubes.  On  all  other  parts  of  the  body  the  hairs  were 
diminished. 

The  hairs  are  implanted  either  singly  or  in  twos  and  threes,  or 
even  four  or  five  together.  The  last  is  the  rule  in  the  foetus,  and, 
so  far  as  the  lanugo  is  concerned,  in  the  adult  also.  The  direction 
of  the  hairs  and  hair-sacs,  is  seldom  perpendicular  to  the  skin,  but 
oblique ;  they  being  arranged  in  curved  lines  which  either  converge 
towards  certain  points  or  lines,  or  diverge  from  them  in  two  or  more 
directions.  Hence  result  a  variety  of  figures,  which  Eschricht 
termed  "  streams,  whorls,  and  crosses ;"  which  are  easily  made  out 
on  the  median  line  of  the  back,  chest,  and  abdomen,  on  the  line 
between  the  thorax  and  the  abdomen,  in  the  axilla,  on  the  scalp,  at 
the  internal  angle  of  the  eye,  and  on  the  elbow.  The  natural  di- 
rection of  the  hairs  is,  in  general,  downwards,  as  shown  especially 
on  the  various  parts  of  the  head.  It  may,  however,  here  be  changed 
by  persevering  efforts.  Very  rarely,  two  hairs  are  found  implanted 
in  the  same  hair-sac. 

'  Treatise  on  the  Skin. 


262 


THE   TISSUES, 


Development  of  the  Hairs, 
Hairs  are  first  seen  in  the  foetus,  upon  the  forehead  and  eyebrows, 
from  the  third  to  the  fourth  mouth ;  the  first  rudiments  of  the  hair- 
sacs   consisting    of    flask-shaped 
^^'       '  solid  processes  of  the  Malpighian 

layer  of  the  epidermis,  formed 
by  its  growth  inwards,  (Fig.  166.) 
The  internal  cells  of  these  be- 
come converted  into  a  delicate 
hair,  surrounded  by  its  internal 
root-sheath;  and  the  external  still 
remaining  soft,  constitutes  the 
outer  root-sheath  and  the  hair- 
bulb.  Thus  the  hairs,  unlike  the 
teeth,  arise  at  once  in  their  to- 
tality. [Kblliker)  The  first  hairs 
are  formed  merely  of  elongated 
cells  similar  to  the  fibrous  sub- 
stance of  the  later  hairs,  the  me- 
dullar}^ cells  being  entirely  ab- 
sent. The  cuticle  is,  however, 
clearly  visible.  The  papilla  is  to 
be  regarded  as  an  outgrowth  of 
the  fibrous  layer  of  the  hair-sac, 
analogous  to  the  papillae  of  the 
skin.^  (Kolliker.) 

The  hairs    themselves    never 

appear  under  from  three  to  five 

weeks  after  the  rudiments  just  described,  e.  g.  at  the  nineteenth 

week,  the  hairs  themselves  are  nowhere  to  be  seen  except  on  the 

forehead  and  eyebrows;  and,  in  the  twenty-fourth  week,  they  are 

'  The  translators  of  Kolliker's  work  (Drs.  Busk  and  Huxley)  adopt  Rciehert's 
view  of  the  development  of  the  hair,  viz.,  that  it  results  from  the  cornification  of 
a  dermic  papilla,  and  regard  a  hair  as  homologous  with  a  tooth,  in  all  its  parts. 
"  The  substance  of  the  shaft  corresponds  with  the  dentine,  offering  even  rudiment- 
ary tubes  in  its  aeriferous  cavities  ;  the  inner  layer  of  the  cuticle  answers  to  the 
enamel,  the  outer  to  Nasmyth's  membrane,  and  whoever  will  compare  these  struc- 
tures will  be  struck  by  the  similarity  even  in  their  appearance.  The  sac  answers 
to  the  dental  capsule ;  the  outer  root-sheath  to  the  layer  of  epithelium  (enamel 
organ)  next  the  capsule  ;  the  fenestrated  membrane  to  the  stellate  tissue,  and  what 
Professor  Kolliker  calls  '  Huxley's  layer,'  to  the  columnar  epithelial  layer  of  the 


A.  Rudiments  of  hair-sacs  I,  I  (foetus,  16  weeks). 
B.  Single  hair-sac  seen  laterally,  a,  h.  Cuticle 
and  stratum  Malpighii  of  the  skin.  i.  Basement- 
membrane  of  hair-sac  prolonged  from  between 
the  stratum  Malpighii  and  the  cerium,  m.  Round- 
ed and  elongated  cells  forming  the  matrix  of  the 
hair. 


THE   HAIR. 


263 


'^.\' 


\ 


not  yet  developed  on  the  hand  and  foot,  and  on  some  parts  of  the 

forearm  and  leg.    In  some 

°  Fig.  lo7. 

parts,  the  hairs  penetrate 

the  epidermis  as  soon  as 
formed  (on  the  eyebrows 
and  eyelashes);  in  others, 
their  points  engage  ob- 
liquely between  the  pro- 
per epidermis  and  the  Mal- 
pighian  layer,  and  grow 
for  a  time  under  the  for- 
mer— as  on  the  chest,  ab- 
domen, back,  and  extre- 
mities. The  lanugo  is  fully 
developed  in  the  twenty- 
third  to  the  twenty-fifth 
week.  It  gradually  ac- 
quires a  darker  color;  be- 
coming even  almost  black 
on  the  head,  before  birth 
in  some  cases.  A  small 
portion,  however,  falls  off,  is  swallowed  by  the  foetus  with  the  liquor 
amnii,  and  thus  appears  in  the  meconium.  Fig.  167  shows  the  pro- 
gress of  the  development  of  the  hairs. 

The  hairs  are  shed  after  birth,  new  ones  forcing  out  and  taking 
the  place  of  the  old  ones.  The  new  are  formed  in  processes 
shooting  off  from  the  original  hair-sacs.  Kolliker  discovered  and 
first  propounded  this  law,  though  it  is  not  yet  certain  that  all  the 
hairs  fall  out,  nor  at  what  precise  period  after  birth.  The  hairs  of 
the  head  in  many  children  are  known  to  fall  out  within  the  first 
two  to  six  months.  The  stages  of  development  of  the  new  hairs, 
as  well  as  the  relation  of  the  hairs  to  the  sebaceous  follicles  already 
alluded  to  (p.  227),  is  shown  by  Figs.  168  and  135. 

The  periodical  shedding  of  the  hairs  of  the  lower  animals  is  pro- 
bably secured  in  the  same  way ;  new  ones  being  formed  in  the  old 

organon  adamantinai"  (p.  190).  Without  precisely  adopting  all  the  analogies  just 
quoted,  we  admit  that  a  hair  is  very  analogous  to  a  tooth  ;  for  we  regard  a  tooth  as 
well  as  a  hair,  as  being  essentially  an  epidermic  (epithelial)  production.  The 
manner  in  which  the  hairs  fall  out,  and  are  succeeded  by  others,  shows  (as  well  as 
their  development),  that  they  are  the  analogues  of  the  teeth  on  the  one  hand,  and 
of  the  epidermis  on  the  other. 


Development  of  hair  (eyebrows).  A.  First  separation  of 
inner  and  outer  portions  of  the  matrix  b.  First  formation 
of  the  hair,  the  point  not  yet  appearing  above  the  sltin.  c. 
Hair  seen  after  its  emersion,  a.  Cuticle  of  skin.  h.  Stra- 
tum Malpighii  of  do.  c.  Outer  root-sheath,  d.  Inner  root- 
sheath,  e.  Bulb.  /.  Shaft,  g.  Point  of  the  hair.  h.  Pa- 
pilla, i.  Basement-membrane,  n,  n.  Commencement  of 
the  sebaceous  glands. 


264 


THE   TISSUES. 

Fie;.  168. 


Fig.  169. 


Development  of  second  eyelashes  (infaut,  one  year  old),  a.  Formation  of  matrix  of  second  hair. 
B.  Incipient  development  of  the  young  hair.  c.  The  same  more  advanced  and  pushing  up  the  old 
hair.  D.  The  young  hair  emerging  from  tlie  opening,  and  the  old  one  about  to  fall  out.  a.  External 
root-sheath.  6.  Internal  do.  of  young  hair.  c.  Cavity  for  the  formation  of  papilla,  d.  Bulb  of  old 
hair.  e.  Its  shaft.  /.  Bulb  of  young  hair.  g.  Its  shaft,  h.  Its  point,  i,  i.  Sebaceous  glands. 
k,  k.  Sweat  ducts.  I.  Passage  of  external  root-sheath  into  the  stratum  Malpighii  of  the  skin.  m. 
First  appearance  of  young  hair. 

sacs,  and  thus  displacing  the  first  hairs,  after  cutting  off  their  supply 
of  nourishment.     The  striking  analogy  in  these  particulars  of  the 

hairs  to  the  teeth,  will  become  ap- 
parent when  we  come  to  speak  of 
the  development  of  the  latter. 

Before  the  old  hair  falls  out,  it 
becomes  entirely  horny  in  consist- 
ence, and  its  bulb  is  no  longer  soft 
and  cellular,  but  solid  and  fibrous 
like  the  shaft,  with  a  clavate  en- 
largement. (Fig.  169.) 

This  condition  marks  the  end  of 
development  and  of  growth ;  and 
all  hairs  which  full  out  present  it. 


Old  liair  falling  out.  A,  sliows  a  diminished  activity 
of  growth  by  the  small  amount  of  pigment  in  the 
colls  of  tho  pulp,  and  the  interrupted  line  of  dark 
modullary  substance.  At  n,  provision  is  made  for 
till'  formation  of  a  new  hair,  a  new  pulp  appearing  in 
connection  witli  tho  old  one.  At  c,  tho  liair  has  died 
and  I'allon  out,  deprived  of  its  sheath  and  of  tho  colls 
composing  tho  pulp  of  a  living  hair. 


THE   HAIR.  265 

And  since  it  is  certain  that  in  full  health,  the  hairs  are  constantly 
falling  out,  doubtless  the  formation  of  new  ones,  as  just  described, 
is  also  simultaneously  taking  place.  Hence  not  un frequently,  two 
hairs  are  seen  corning  out  of  the  same  aperture,  as  before  stated — 
the  old  and  the  new  one.  When  a  hair  is  pulled  out,  however,  it 
breaks  off  just  above  the  bulb,  and  another  is  produced  from  the 
latter  directly,  as  at  first.  Heusinger  found  that  on  pulling  out  the 
whiskers  of  dogs,  they  were  reproduced  in  a  few  days  from  the  old 
sacs.  And  when  the  hairs  fall  out  after  sickness,  it  is  probable  that 
they  are  reproduced  from  the  old  sacs,  since  the  latter  remain  for 
a  long  time.  {E.  H.  Weber.) 

Uses  and  Physiological  Relations  of  the  Hair. 
The  uses  of  the  hair  are  various,  depending  partly  upon  its  phy- 
sical and  partly  on  other  characteristics. 

1.  The  hair  is  for  protection,  whether  against  cold,  or  other 
agents,  as  on  the  head,  &c. ;  against  exposure  to  light,  as  in  case  of 
the  eyebroAvs. 

2.  It  is  for  concealment,  as  on  the  pubes,  &c. 

3.  It  prevents  the  ingress  of  foreign  bodies  into  the  passages 
opening  externally;  as  the  vibriss£e  of  the  nostrils,  the  cilia  of  the 
eyelids,  and  the  hairs  sometimes  existing  in  the  external  meatus 
auditorius. 

4.  The  hair  gives  character  and  expression,  as  the  beard ;  which 
is  also  protective  against  changes  of  tempei^ature  in  circumstances 
requiring  its  agency  in  this  respect.  A  tendency  to  affections  of 
the  bronchial  mucous  membrane  is,  therefore,  frequently  removed 
by  allowing  the  beard  to  grow. 

5.  The  hair  is  for  ornament,  as  that  of  the  head. 

The  hairs,  like  the  nails,  grow  again  if  cut  or  worn  away;  other- 
wise they  remain  at  their  typical  length  in  the  various  parts  of  the 
body.  Berthold  found  the  hairs  of  the  heads  of  females  from  16  to 
24  years  old,  grew  about  7  lines  a  mouth.  If  the  beard  were  shaved 
every  12  hours,  it  would  grow  to  from  5|  to  12  inches,  and  if  every 
2-1  hours,  to  from  5  to  7J  inches,  per  annum.  Shaving  once  in  36 
hours  would  reduce  the  annual  growth  to  from  •!  to  6|  inches. 
The  beard  grows  J  faster  by  day  than  during  the  night;  and  in 
18  days,  about  ^-^  more  in  summer  than  in  winter.  Kolliker 
supposes  that  each  sac  is  supplied  by  the  vessels  of  the  papilla 
with  a  sufficiency  of  nourishment  to  develop  the  hair  to  its  tj-pical 


266  THE   TISSUES. 

length,  and  to  keep  the  whole  hair  in  a  state  of  moisture  and  vi- 
tality ;  and  that  if  the  hair  be  cut,  the  then  superfluous  amount  of 
nourishment  develops  the  hair  till  it  again  attains  to  the  previous 
length.  This  is  equivalent  to  saying  that  the  hair-sacs  have,  each, 
the  power  to  develop  a  hair  of  a  determinate  length,  it  being  also 
the  function  of  each  to  maintain  this  length;  so  that  if  the  hair  is 
cut,  it  again  attains  to  it.  Kolliker  states  that  cut  hairs  do  not  pro- 
duce new  points,  while  others  have  asserted  the  contrary.  When- 
ever they  become  pointed  again  after  being  cut,  as  is  quite  certain 
in  many  cases,  it  is  doubtless  from  mere  mechanical  causes  already 
suggested,  and  not  from  developmental  agencies.  The  growth 
takes  place  in  the  hair-sac,  and  at  the  root;  the  shaft  being  thus 
constantly  protruded,  till  the  hair  attains  its  normal  length. 

Though  the  hairs  are  not  vascular  they  are  not  a  dead  substance. 
Fluids  are,  doubtless,  effused  through  them  which  serve  for  the 
maintenance  of  their  vitality,  ascending  from  the  bulb  through  the 
fibrous  portion  and  the  medulla  to  every  part,  probably  by  mere 
imbibition.  After  accomplishing  their  object,  they  pass  off  by  eva- 
poration, and  another  supply  is  afforded.  From  without,  the  hair 
can  absorb  fluids  only  in  the  form  of  vapor.  The  oily  matter  of 
the  sebaceous  follicles  is  spread  upon  the  cuticle  of  the  hair,  but 
does, not,  probably,  penetrate  it  at  all;  nor  is  there  any  greasy  fluid 
afforded  within  by  the  medullary  cells. 

The  existence  of  air- vesicles  in  the  medullary  axis,  can  arise  only 
from  a  diminished  supply  of  the  fluids  from  the  sac,  compared  with 
the  amount  evaporated.  It  is  thus  due  to  a  partial  drying  up  of 
the  hair.  The  fibrous  portion  appears  to  be  the  most  actively  nou- 
rished, and  is  the  most  rich  in  fluids,  though  comparatively  so  hard. 
Gray  hairs  contain  more  of  the  air-vesicles,  and  to  them  its  silvery 
appearance  is  due.  That  their  vitality  is  not,  however,  essentially 
diminished,  is  proved  from  the  fact  that  they  grow  rapidly  when 
cut. 

Tlius  the  hairs  live,  and  must,  of  course,  be  modified  in  their  de- 
velopment and  growth  by  the  vital  conditions  of  the  skin.  The 
condition  of  the  hair  is,  therefore,  an  index  of  that  of  the  skin.  If 
they  are  soft  and  shining,  it  may  be  inferred  that  the  skin  is  tur- 
gescent  and  active;  if  dry  and  harsh,  that  it  is  in  a  collapsed  and 
inactive  condition. 

Any  essential  modification,  therefore,  in  the  circulation  of  the 
skin,  and  hence  of  the  blood  supplying  the  hair-sacs,  modifies  the 


THE   HAIR,  267 

condition  of  the  hair.  Thus  it  may  fall  out  after  sickness,  espe- 
cially from  fevers.  In  old  persons,  also,  it  falls  out,  probably  from 
an  obliteration  of  the  vessels  of  the  hair-sacs. 

The  process  of  whitening  of  the  hairs  (gray  hairs)  is  very  ob- 
scure. Its  immediate  cause  is  chiefly  a  decoloration  of  the  fibrous 
portion  of  the  hairs,  and  an  increase  of  the  air-vesicles ;  but  how 
this  is  produced  is  not  understood.  Intellectual  activity,  grief, 
nervous  influences,  and  old  age,  are  certainly  concerned  in  it.  The 
rapidity  with  which  this  change  may  be  effected,  also  testifies  to  the 
vitality  of  the  hair ;  cases  having  occurred  in  which  it  has  become 
gray  within  a  few  hours,  under  the  influence  of  violent  emotions.' 

Dzondi  and  others  have  succeeded  in  transplanting  hairs  with 
their  sacs. 

The  fact  that  the  hairs  of  the  head  may  become  erect  under  the 
influence  of  powerful  emotions,  is  usually  associated  with  the  cutis 
amerina,  so  called.  We  should,  however,  associate  it  with  the  fact 
established  by  Eylandt,  that  the  hair-sacs  of  various  parts  of  the 
body  have  smooth  muscular  fibres  inserted  into  them,  and  which 
he  has  termed  the  arrectores  inli. 

The  presence  of  sulphur  in  hair  accounts  for  the  peculiar  odor 
evolved  by  its  combustion.  The  various  hair-dyes  also  act  by 
combining  with  it,  and  producing  a  sulphuret  of  the  metal  they 
respectively  contain,  as  silver,  manganese,  &c.  The  nitrate  of  silver 
is  most  frequently  used  (p.  257). 

Pathological  States  and  Developments  of  the  Hair. 

There  may  be  an  excessive  growth  or  a  falling  out  of  the  hairs. 
They  may  also  be  developed  in  abnormal  directions,  as  is  often  seen 
on  the  head.  The}'  may  be  found  abnormally,  on  even  mucous  sur- 
faces. Hairs  have  been  developed  in  the  intestines,  the  gall-bladder, 
in  ovarian  cysts,  in  steatomatous  and  encysted  tumors,  and  in  the 
lungs  even.  {Mohr''s  case.)  They  are  often  largely  developed  on 
moles  and  nasvi.  In  all  these  cases  they  possess  sacs  and  root- 
sheaths,  and  in  all  respects  a  normal  structure.     Indeed,' since  they 

'  A  Captain  P.,  of  Vermont,  was  captured  by  a  party  of  British  soldiers  in  1813 
on  tlie  Canadian  frontier,  and  put  under  guard  in  the  evening,  with  the  assurance 
that  he  would  be  shot  the  next  morning.  When  the  appointed  time  had  arrived 
his  hair  had  entirely  changed  from  a  jet  black  to  gray. 

Dr.  J.  W.  Richards,  of  New  York  city,  mentioned  to  the  author  a  man  whose 
hair  changed  from  a  jet  black  to  gray  and  back  again  three  times  in  the  course  of 
ten  years.  No  cause  could  be  assigned.  He  was  in  perfect  health,  and  not  of  an 
excitable  temperament,  and  the  change  began  at  the  age  of  thirty-five  years. 


268  THE    TISSUES. 

are  an  epithelial  production,  Ave  should  not  be  unprepared  to  find 
them  wherever  an  epithelium  exists,  though  they  have  not  been 
found  on  the  serous  membranes. 

ISTo  hairs  are  developed  upon  cicatrices  on  the  skin. 

The  falling  out  of  the  hair  of  the  head,  constitutes  baldness 
(alopecia).  When  due  to  an  atrophy  of  the  hair-sacs,  remedies  are, 
of  course,  of  no  avail.  One  cause  of  its  far  greater  frequency  in 
men  than  in  women,  is,  very  probably,  the  style  of  hat  so  generally 
worn,  especially  in  this  country;  and  which  by  its  stiffness,  its  form, 
and  its  heating  powers,  at  the  same  time  banishes  all  comfort,  and 
violates  the  principles  of  good  taste,  common  sense,  and  physiolo- 
gical science. 

Some  diseases  of  the  hair  are  produced  by  vegetable  parasites 
(fungi)  in  the  interior  of  the  hair  itself  This  is  the  case  with 
herpes  (or  tinea)  tonsurans  {Grvhy)\  and  Y)r.  Jenner,  of  London,  has 
shown  that  the  sulphurous  acid  destroys  the  parasite  and  cures  the 
four  varieties  of  this  disease.*  In  porrigo  decalvans  ( Willaii)^  the 
fungus  is  under  and  around  the  cuticle  of  the  hair.  {Grvhy') 

In  plica  Polonica,  in  which  the  hair  becomes  matted  together, 
and  appears  even  sensitive,  a  fungus  is  developed,  according  to 
Guensberg  and  Walther,  in  the  bulb  and  shaft  of  the  hairs,  and 
partly  destroys  them.     Munter,  however,  found  no  such  fungus. 


CHAPTER    II. 


YELLOW   FIBROUS   TISSUE. 


The  yellow  fibrous  tissue  (elastic  tissue),  presents  three  varieties 
of  form: — 

1.  The  most  common  form  consists  of  solid  fibres  of  a  yellowish 
color,  bifurcating  or  even  trifurcating,  and  anastomosing  very  freely; 
curled  or  coiled  up  at  their  extremities,  and  sometimes  being  coiled 
around  other  tissues.  These  fibres  vary  from  ^rouo  to  -^^^-^  of  an 
inch  in  diameter,  and  are  often  studded  with  nuclei.  More  or  less 
of  them  are  always  found  in  connection  with  the  white  fibrous  tis- 
sue. (Fig.  170,  A.) 

2.  Another  form  found  by  Queckett  in  the  ligamentum  nucha?  of 
the  giraffe,  consists  of  similar  coiling  and  bifurcating  fibres,  each 

'  Tinea  favosa,  tonsurans,  decalvans,  and  sycosa.  See  Am.  Med,  Month!//,  INLirch, 
1854,  p.  240. 


YELLOW   FIBROUS   TISSUE. 


269 


being  marked  -witli  transverse  stria3,  not  extending  quite  across 
them,  but  being  principally  confined  to  the  centre  of  each.  Kolli- 
ker  asserts  that  this  appearance  is  due  to  the  formation  of  little 
cavities  within  the  fibres.  (Fig.  170,  B.) 


A.  Yellow  elastic  fibres  from  the  ligamentum  nuchse  of  a  sheep,  b.  Yellow  fibres  from  the  liga- 
mentiim  nuchse  of  the  giraffe,  c.  One  of  the  same,  magnified  500  diameters.  D.  Vessels  of  the  liga- 
mentum nuch£e  of  a  young  calf  (Queckett.) 


o.  The  third  variety  consists  of  flat,  rather  broad,  somewhat 
brittle,  and  much  ramifying  bands  (Fig.  171),  often  so  arranged  as 
to  form  a  network  (or  in  the  form  of  the  finest,  straight  threads 
(Fig.  172),  as  in  the  peritoneum  of  some  young  animals),  as  found 
in  the  middle  coat  of  arteries. — The  elastic  fibres  studded  with 
nuclei  have  been  called  nuclear  fibres.  But  all  may  have  been  so  at 
first;  at  least  the  largest  were  originally  as  small  as  those.  (Fig.  173). 

Elastic  fibres  cannot  be  isolated  for  examination  by  mere  mecha- 
nical means,  since  they  never  occur  independently  of  other  histo- 
logical elements.  They  always  appear  where  the  white  fibrous 
tissue  exists,  and  are  often  blended,  as  in  the  middle  coat  of  arteries, 
with  the  smooth  muscular  fibres.  The  last  two  elements  may,  how- 
ever, be  removed  by  boiling  with  acetic  acid,  and  then  adding  a 
dilute  solution  of  potash,  when  the  isolated  elastic  fibres  remain. 


270  THE   TISSUES. 

The  elastic  fibres  are  arranged  in  three  principal  forms  in  the 
various  organs:  1,  wide-meshed  or  intricately  formed  nets  with 
hook-like  indentations,  and    forming  considerable   masses;   2,  as 

Fig.  171.  Fig.  172. 


Fig.  171.  Elastic  networli  from  the  tunica  media  of  tlie  pulmonary  artery  of  a  horse,  -(vitli  cavitie.'^ 
in  the  fibres.— Magnified  350  diameters.   {KoUiker.) 

Fig.  172.  Yellow  fibrous  element  of  the  areolar  tissue  of  serous  membrane,  from  the  mesentery  of 
the  rabbit,  treated  with  acetic  acid.     (Magnified  300  diameters.) 

bundles  of  fibres  nearly  parallel  (as  in  certain  ligaments),  or  twining 
around  other  tissues  in  a  spiral  manner;  3,  forming  a  fenestrated 
membrane  with  tolerably  large  intervals,  as  in  the  arteries. 

When  the  yellow  elastic  fibres  form  masses,  as  in  the  ligamentum 
nuchas,  &c.,  no  nerves  or  lymphatics  are  found  among  them.  The 
vessels,  comparatively  few  in  number,  lie  between  the  fibres  and 
parallel  to  them,  much  like  those  of  tendon.  (Fig.  170,  D.)  The 
connecting  branches,  however,  arc  not  transverse,  but  pass  off  at 
angles  of  about  40°;  so  that  the  spaces  inclosed  by  the  vessels  have 
a  somewhat  rhoraboidal  outline. 

Chemical  Comiiosition  of  Elastic  Tissue. 

The  investigations  of  chemists  have  not  yet  led  to  any  very  ac- 
curate knowledge  of  the  composition  of  this  tissue,  and  its  general 
chemical  relations. 

Cold  acetic  acid  does  not  act  upon  it ;  and  therefore  displays  it 
when  blended  with  white  fibrous  tissue,  by  dissolving  the  latter,  and 
thus  isolating  the  former.  Mulder  and  Dundas  found  the  fibres 
entirelv  unchanged  after  boiling  forty  hours,  and  obtained  no  gela- 


YELLOW   FIBROUS   TISSUE.  271 

tinous  substance  from  them.  Soberer  states  that  clastic  tissue  is 
proteine  plus  two  equivalents  of  water  (Pro4-2HO).  Robin  and 
Verdeil  have,  however,  found  in  it  a  peculiar  immediate  principle, 
which  they  have  called  elasticine  (p.  100). 

Elastic  tissue  is  unaffected  by  all  the  weaker  acids,  and  is  not  dis- 
solved by  the  gastric  fluid.  It  resists  decomposition  longer  than  any 
other  soft  and  moist  tissue.     Its  ash  constitutes  17  per  cent,  of  it. 

Properties  and  Uses  of  Elastic  Tissue. 
The  yellow  fibrous  tissue  manifests  no  vital  properties,  except  so 
far  as  to  secure  and  maintain  its  own  development.  As  a  con- 
stituent part  of  the  organism,  it  manifests  only  ^jA^/sfcaZ  properties; 
of  which  its  extensibility  and  elasticity  are  the  peculiar  and  essen- 
tial ones.  It  is,  however,  also  flexible,  and  considerably  strong. 
^Ir.  Queckett  found  tbat  the  ligamentum  nuchse  of  a  giraffe,  6  feet 
and  2  inches  in  length  during  life,  contracted  at  once,  on  being 
removed,  to  4  feet;  and  that  an  immense  force  was  required  to 
stretch  it  again  to  5  feet.'  The  elasticity  of  this  tissue  is  preserved 
for  almost  an  unlimited  period ;  it  being  revived  by  the  application 
of  water  after  the  fibres  have  been  long  kept  in  a  dried  state. 

Uses, — The  yellow  fibrous  tissue  is  useful  by  reason  especially  of 
its  extensibility  and  elasticity.  Whenever  a  tissue  is  required  pos- 
sessing tbese  properties,  as  in  extensible  ligaments  (the  ligamentum 
nuchfe,  chordas  vocales,  &c.)  and  in  the  bloodvessels,  this  is  the  one 
found.  Its  properties,  indeed,  are  very  similar  to  those  of  gum- 
elastic,  except  that  it  is  mucb  stronger.  Its  use  in  each  particular 
part  or  organ  will  at  once  be  inferred,  therefore,  from  tbe  following 
account  of  its  distribution  in  the  various  organs  of  tbe  human  body. 

Distribution  of  the  Yellow  Fibrous  Tissue. 

The  yellow  elastic  tissue  forms  the  greater  portion  of  the  follow- 
ing structures :  tbe  ligamentum  nuchas,  the  ligamenta  subflava,  the 
crico-thyroid  and  the  thyro-hyoid  membranes,  the  thyro-arytenoid 
ligaments  (chordas  vocales),  the  stylo-hyoid  ligament  {TTassall),  the 
longitudinal  bands  of  the  trachea  and  bronchi,  the  internal  lateral 
ligament  of  the  lower  jaw,  and  the  ligamentum  suspensorium  penis. 
It  is  also  found  at  the  base  of  the  epiglottis,  and  the  fascia  trans- 
versalis  is  composed  in  great  part  of  it.    It  combines  with  the  white 

'  The  weight  of  the  entire  ligameut  was  more  thau  8  pounds. 


272  THE   TISSUES. 

fibrous  tissue  to  form  the  areolar  tissue,  wherever  found;  and  of  the 
third  form  of  it  the  middle  coat  of  the  large  arteries  is  almost  ex- 
clusively, and  that  of  the  smallest  in  part,  formed.  It  also  abounds 
between  the  air-cells  of  the  lungs. 

None  of  the  preceding  structures  are,  however,  formed  of  the 
elastic  tissue  alone.  E.  g.  between  the  yellow  fibres  of  the  liga- 
menta  subflava,  ^^ivhich  are  not  collected  into  either  fasciculi  or  lamellce, 
but  are  continuously  connected  throughout  the  entire  thickness  of 
each  yellow  ligament,  there  is  interposed  some  white  fibrous  tissue ; 
upon  the  whole  in  small  quantity,  but  demonstrable  in  every  pre- 
paration, and  occurring  in  the  form  of  lax,  undulating  fasciculi, 
which  are  arranged  parallel  with  the  principal  direction  of  the 
elastic  fibres."   {Kblliker,  p.  284.) 

Distribution  of  the  Elastic  Tissue  in  the  Lower  Animals. 

In  all  the  vertebrated  classes  this  tissue  is  found  in  the  same 
localities  as  in  man,  and  in  some  places  besides — as  in  the  ligaments 
of  the  cat's  claw,  and  in  the  alary  membrane  of  the  mammals. 

In  large  animals,  as  the  elephant  and  rhinoceros,  the  yellow  fibrous 
tissue  is  employed  in  the  form  of  a  belt  to  support  the  abdominal 
parietes.  [Queckett.)  lu  the  ligameutum  nuchteof  the  giraffe,  before 
alluded  to,  the  fibres  are  marked  with  transverse  striae,  extending 
through  about  the  central  third  of  their  width.  The  internal  por- 
tions were,  however,  made  up  entirely  of  the  common  plain  fibres. 
Similar  striated  fibres  also  are  found  in  the  rhinoceros,  and  the 
sheep;  and  even  in  arteries. 

A  variety  of  this  tissue  constitutes  the  ligament  supporting  the 
expanded  wings  of  the  larger  birds,  as  the  eagle,  crane,  heron,  &c. 
It  also  exists  in  the  lungs  of  birds. 

It  is  a  ligament  of  elastic  tissue  which  in  the  bivalve  moUusca 
keeps  the  valves  open  whenever  the  adductor  muscle  ceases  to  close 
them  by  its  contraction.  In  the  oi/ster  this  tissue  is  placed  within  the 
hinges,  and  therefore  is  compressed  whenever  the  valve  is  closed. 
Hence  the  compressed  elastic  tissue  forces  the  valves  apart  when 
the  muscle  ceases  to  keep  them  closed.  In  the  cockle  the  elastic 
tissue  is  placed  externally  to  the  hinge,  and  being  stretched  when 
the  valves  are  closed,  pulls  them  open  by  its  elasticity  whenever  the 
adductor  muscle  ceases  to  act. 

The  form  of  this  tissue  occurring  in  the  middle  coat  of  arteries, 
was  found  in  that  of  the  aorta  of  a  whale  to  be  IJ  inch  thick;  the 
diameter  of  the  vessel  being  12  inches,  and  its  length  over  50  feet. 

Development  of  Elastic  Tissue. 
The  supposition  of  Schwann,  that  this  tissue  is  developed  from 


YELLOW   FIBROUS   TISSUE. 


273 


Fig.  173. 


Fig.  174. 


cells,  receives  increasing  support  from  recent  investigations.  These 
are  peculiarly  fusiform  or  stellate,  sharply-pointed  cells,  producing 
long  fibres  or  reticulations  by  their  coalescence.  The  nuclei  some- 
times remain  in  the  elongated  or  fibriform  cells,  and  thus  the  latter 
have  been  termed  nucleus  fibres.  [Gerher.)  In  other  cases  all  traces 
of  the  nuclei  disappear,  and  perfectly  homogeneous  fibres  or  net- 
works are  produced.  These  may  remain  fine  through  life  as  at 
first,  or  become  coarse  by  increase  in  thickness.  When  once  per- 
fectly developed,  the  fibres  undergo  very  little  change ;  though  so 
long  as  the  nuclei  or  other  indications  of  the  original  cells  still 
appear,  a  certain  amount  of  metamorphosis  and  repair  may  take 
place  (p.  269). 

It  is  the  development  of  the  nuclear  fibres  almost  alone  that  has 
been  accurately  examined;  and  KoUiker  has  demonstrated  that  the}^ 
are  formed  from  fusiform  cells, 
iiiov  ^'^  500  of  an  inch  in  length, 
which  first  appear  in  the  foetus  of 
from  two  to  three  months  (Fig. 
173),  the  fibres  of  the  white  fibrous 
tissue  being  already  well  formed. 
In  the  foetus,  at  birth,  the  cells 
have  so  elongated,  and  coalesced 
into  a  network,  that  they  can  no 
longer  be  isolated  as  before. 

What  is  asserted  of  the  nuclear 
fibres  also  holds  good  of  the  larger 
elastic  fibres ;  for  there  is  reason 
to  believe  that  all  these  have  at 
one  time  been  nuclear  fibres.  In 
fact,  there  is  not  a  single  true  elas- 
tic fibre  in  the  new-born  child; 
since  even  those  of  the  ligament- 
um  nuchas,  &c.,  when  largest,  are 
not  more  than  y^^oo  ^o  xso^o  of 
an  inch  in  diameter  (Fig.  174),  and 
from  these,  doubtless,  the  coarse 
fibres  are  subsequently  developed. 
In  some  places,  even  in  the  adult, 
the  original  condition  of  a  system 

of  canals  (tubular  cells)  is  still  to     bom  infant.— Magnified  350  dlam'rs.  (KoUiker.) 

18 


Fig.  173.  Formative  cells  of  the  elastic  fibres 
from  the  tendo-Achillis.  a.  Of  a  four  months' 
embryo,  b.  From  a  seven  months'  foetus  ;  a  few 
cells  free,  with  one  and  two  processes,  others 
united  by  twos  and  threes.  (Mag'd  350  diams.) 

Fig.  174.  Stellate  formative  cells  of  the  nu- 
clear fibres  out  of  the  tendo-Achillis  of  a  new- 


274  THE   TISSUES. 

some  extent  retained.  But  it  by  no  means  follows,  as  Virchow 
asserts,  that  all  the  nuclear  fibres  are  hollow  tubes  for  the  nutrition 
of  the  white  fibrous  tissue  blended  with  the  elastic.  On  the  con- 
trary, Kcilliker  maintains  that  all  fine  elastic  fibres,  which  no  longer 
present  any  traces  of  the  original  cell,  are  solid^  and  are  useful  only 
so  far  as  they  are  elastic — as  those  of  the  areolar  tissue,  of  the  co- 
riura  of  the  skin  and  serous  and  mucous  membranes,  of  the  fasciae, 
the  perimysia,  the  periostea,  the  dura  mater,  and  the  walls  of  vessels. 
For  the  cornea  alone,  where  the  elastic  tissue  remains  in  quite  an 
embryonic  condition,  does  he  adopt  Virchow's  hypothesis.  In  any 
instance  or  any  part  where  the  elastic  tissue  is  still  undeveloped, 
this  may  be  the  case  also;  but,  if  so,  this  result  is  secondary  and 
incidental,  and  not  the  definite  object  of  the  tissue  under  consi- 
deration, as  Virchow  maintains.  Donders  maintains  that  all  cell- 
membranes  consist  of  a  substance  identical  with,  or  at  all  events 
very  similar  to,  elastic  tissue.  This  opinion  rests,  on  the  one  hand, 
on  the  supposed  development  of  elastic  tissue,  and  especially  of 
nuclear  fibres,  from  the  walls  of  cells;  and,  on  the  other,  on  the 
circumstance  that  certain  membranes  and  textural  elements,  which 
in  their  physical  and  chemical  properties  closely  approximate  to 
elastic  tissue  (e.  g.  nerve-sheaths),  may  be  found  to  be  formed  from 
cell-membranes.  [Lehmann)  We  cannot,  however,  accept  this  view 
in  its  general  application ;  for  the  walls  of  very  young  cells,  of 
cytoid  corpuscles  and  blood-cells,  and  the  cells  of  the  deepest  layers 
of  compound  epithelia,  are  readily  soluble  in  acetic  acid  and  in 
very  dilute  alkalies. 

If  the  clastic  tissue  is  removed  or  destroyed,  it  is  not  regenerated ; 
but  an  imperfect  areolar  tissue  takes  its  place.  Pathological  new 
formations  of  it  are,  however,  not  rare. 

The  growth  of  the  yellow  fibrous  tissue  is  secured  by  an  increase 
in  size  of  each  fibre,  as  well  as  by  the  formation  of  new  ones,  doubt- 
less. Kolliker  found  that  the  fibres  in  the  ligamentum  nucha)  of 
the  calf  are  considerably  finer  tlian  those  of  the  ox;  and  that  in 
the  new-born  child  not  a  single  true  elastic  (coarse)  fibre  exists,  but 
only  the  nuclear  (fine)  fibres. 

Pathological  New  Formations  of  Elastic  Tissue. 

Fibres  of  this  tissue  often  occur  in  pathological  cpigeneses,  in  great 
numbers  and  in  considerable  masses ;  the  contiguous  fibres  being 
also  interwoven  into  a  close  and  fine  lattice-work,  presenting  the 
same  morphological  conditions  as  coagulated  (fibrillated)  ytirme,  and 


WHITE   FIBROUS   TISSUE. 


275 


for  which  the  finer  fibres  may  be  mistaken.  They  are,  however,  at 
once  distinguished  by  their  unchangealjleness  under  the  action  of 
acetic  acid  and  dilute  solutions  of  the  alkaline  carbonates. 


CHAPTEE    III. 


WHITE    FIBROUS    (COLLAGENOUS)   TISSUE. 


Much  confusion  has  resulted  from  the  blending  together  by  au- 
thors, in  their  descriptions,  of  the  white  and  the  yellow  fibrous 
tissues,  under  the  name  of  connective,  tissue.  Kolliker  includes  under 
the  latter  designation  the  white  fibrous  tissue  on  the  one  hand,  and 
on  the  other,  as  mixed  with  it,  elastic  fibres,  fat-cells,  cartilage-cells, 
and  pigment-cells  of  difierent  kinds.  Lehmann  regards  connective 
tissue  and  areolar  tissue  as  being  the  same,  and  both  as  being  iden- 
tical with  the  white  fibrous  tissue;  the  areolar  tissue  being  its  amor- 
phous (or  loose — Kolliker)^  and  the  connective  tissue  the  formed  or 
solid  variety. 

True  connective  tissue,  or  that  which  connects  together  different 
parts  and  organs,  is  almost  invariably  found  to  consist  of  two  or 
more  distinct  tissues  interwoven,  of  which  the  white  fibrous  tissue 
is  usually  merely  the  most  abundant.  White  fibrous  tissue  alone,, 
therefore,  cannot  properly  be  termed  connective  tissue,  any  more 
than  the  yellow  fibrous  which  is  almost  always  blended  with  it. 

We  shall  therefore  adhere  to  both  fact 
and  simplicity  if  we  describe  the  white 
fibrous  tissue  under  this  name  as  a  sim- 
ple tissue ;  and  speak  of  its  union  with 
the  yellow  fibrous  tissue  in  the  areolar 
tissue  (and  which  is  usually  the  con- 
nective tissue)  further  on. 

The  white  fibrous  tissue  is  so  named 
from  its  appearing  under  the  microscope 
to  consist  of  very  fine  fibres  (Fig.  175), 
4(ji(T(j  to  2  4-1-0  0  of  an  inch  in  diameter, 
a  pale  color,  homogeneous  appearance, 
and  non-striated.  {Kolliker.)     These  ap- 


Fig.  175. 


Willi.   Iiln    1 

(Migiiilioil 


111  ligament 
di.iiiieteri ) 


276  THE   TISSUES. 

parent  fibres  are  united  by  a  clear  connecting  gelatinous  substance 
(homogeneous  substance),  and  fasciculi  are  thus  formed,  averaging 
3oVo  to  04V0  o^  ^^  i^ch  in  diameter.  These  bundles  somewhat 
resemble  the  striated  muscular  fibres,  but  have  no  actual  striae,  or 
external  investments  at  all  comparable  to  the  myolemma,  and  are 
smaller.  They  are  arranged,  like  long,  wavy  cords,  so  as  to  form 
large  lamellce  and  bundles  (as  in  ligaments);  or  they  coalesce,  like 
the  elastic  tissue,  into  networks  and  meshes.  In  rare  cases  the 
bundles  appear  to  be  homogeneous,  and  not  composed  of  fibres,  as 
in  the  perineurium  (Remak's  fibres).  In  some  cases,  indeed,  neither 
bundles  nor  fibres  can  be  made  out;  and  this  has  been  called  homo- 
geneous (or  Reichert's)  connective  tissue.  This  may  be  regarded  as 
either  white  fibrous  or  areolar  tissue,  in  an  undeveloped  state. 

Todd  and  Bowman — and,  since,  Reichert  and  Dr.  Paulsen — main- 
tain that  the  fibrillation  of  this  tissue  is  merely  apparent;  it  being 
really,  in  its  normal  state,  a  homogeneous  mass,  marked  by  longi- 
tudinal parallel  streaks,  having  at  times  a  tendency  to  split  up  "acZ 
infinitum,''^  and  splitting  into  membranes  rather  than  fibrous  frag- 
ments. Though  we  agree  with  the  writers  just  quoted,  the  fibril- 
lated  appearance  justifies  the  name  we  still  prefer  for  this  tissue ; 
and  it  at  once  occurs  that  if  no  minute  fibres  exist,  like  those  de- 
scribed by  KoUiker,  then  the  bundles,  so  called,  become  fibres  of 
larger  dimensions.  For  every  histological  purpose,  therefore,  the 
term  white  fibrous  tissue  is  to  be  preferred. 

No  nerves  or  lymphatic  vessels  are  supplied  to  this  tissue.  The 
manner  in  which  vessels  are  distributed  to  parts  composed  of  it, 
will  be  shown  further  on  (Fig.  176). 

Chemical  Composition  of  White  Fibrous  Tissue. 
This  tissue  is  about  63  per  cent,  water,  and,  like  bone  and  the 
teeth,  affords  gelatine  to  boiling  water.  It  has  hence  been  termed 
one  of  the  gelatinous  tissues.  That  the  gelatine  does  not,  however, 
pre-exist  in  these  three  tissues,  but  is  formed  by  decomposition  of 
another  substance,  has  already  been  shown  (p.  98).  The  substance 
thus  converted  into  gelatine  is  called  osteine,  and  is  the  same  in 
bone,  teeth,  and  white  fibrous  tissue.  The  apparent  fibres,  before 
mentioned,  swell  up  and  assume  a  viscid,  hyaline  appearance  in 
alkalies,  and  cannot  be  again  brought  into  view  by  the  addition  of 
water.     The  same  result  follows  if  a  solution  of  caustic  potash  of 


WHITE    FIBROUS   TISSUE.  277 

10  per  cent,  be  used,  and  the  transparent  mass  may  be  torn  with 
equal  ease  in  any  direction.  If,  however,  the  potash  be  now  re- 
moved by  acetic  acid,  the  original  texture  returns.  {Paulsen^ 
While  acetic  acid  obscures  the  parallel  lines,  and  renders  the  mass 
transparent,  it  usually  brings  into  view  broken,  elongated  cor- 
puscles, the  remains  of  the  developmental  cells.  {Kolliker)  The 
addition  of  a  mineral  acid  brings  the  lines  into  view  again. 

It  is  the  white  fibrous  tissue  which  some  histologists  have  termed 
the  collagenous  element  of  the  areolar  tissue,  and  the  fibriUated  col- 
lagenous^ substance.  It  will  be  frequently  termed  the  "collagenous 
tissue"  and  the  "collagenous  element,"  in  the  subsequent  portions  of 
this  work. 

Properties  and  Uses  of  White  Fibrous  Tissue. 

White  fibrous  tissue,  like  the  yellow  fibrous,  manifests  no  vital 
properties  (save  the  power  of  securing  and  maintaining  its  develop- 
ment), hut  2^hysical  properties  merely,  viz:  great  strength,  great 
flexibility,  and  almost  total  inextensibility.  It  may,  however,  be 
somewhat  extended  by  a  slowly-acting  and  long- continued  force. 

The  strongest  cords  used  in  the  arts  are  made  of  this  tissue — as 
musical  strings,  &c.  Mascagni  calculated  that  the  human  tendo- 
Achillis  will  sustain  a  weight  of  1,000  pounds. 

Its  flexibility  is  owing  to  the  water  it  contains.  When  dried,  it 
becomes  quite  rigid.  In  this  state,  also,  it  completely  resists  the 
putrefactive  process. 

Uses. — In  all  cases  where  a  tissue,  strong,  flexible,  and  totally 
inextensible,  is  needed,  this  is  the  one  found.  Ligaments  and  ten- 
dons are  composed  almost  exclusively  of  it.  Its  uses  in  particular 
parts  and  organs  vary,  as  seen  in  the  following  paragraphs.  Some- 
times it  is  merely  protective  of  the  softer  parts  it  incloses ;  as  in 
case  of  the  sclerotica,  the  tunica  albuginea  testis,  &c. 

Distribution  of  the  White  Fibrous  Tissue. 
1.  White  fibrous  tissue  constitutes  the  greater  portion  of  tendons, 
aponeuroses,  and  articular  ligaments.  It  also  constitutes  a  large 
portion  of  the  fibrous  membranes,  so  called — viz.,  the  periosteum, 
perichondrium,  and  dura  mater — and  enters  with  the  yellow  fibrous 
into  the  formation  of  the  areolar  tissue.    Hence  it  forms  the  greater 

'  From  noWa,  glue,  gelatine,  and  ^hio?  ;  gelatine-producing ;  synonymous  -n-itli 
gelatigenous. 


278 


THE   TISSUES. 


Fig.  176. 


part  of  the  corium  of  the  skin,  and  of  serous  and  mucous  mem- 
branes ;  and  of  the  vascular  membranes,  so  called,  as  the  pia  mater 
and  the  plexus  choroides. 

2.  It  also  forms  the  white,  dense  tunics  of  many  soft  organs;  as 
the  perineurium,  the  sclerotica  and  cornea,  the  fibrous  coat  of  the 
spleen  and  kidneys,  and  the  fibrous  tunic  of  the  testis,  ovaries, 
penis,  and  clitoris. 

In  all  the  preceding  structures  the  yellow  fibrous  tissue  is  found 
in  combination  with  the  white.  The  arrangement  of  the  latter,  in 
all  except  the  true  membranes,  will  be  disposed  of  here. 

1.  Structure  of  tendons  and  ligaments.  These  consist  of  parallel 
bundles  of  white  fibrous  tissue,  united  by  loose  areolar  tissue  into 
large  cords.     Between  these  the  vessels  ramify,  and  a  relatively 

very  small  number  of  elastic  fibres,  or 
of  networks  formed  of  them.  Fig. 
261  shows  a  transverse  section  of  a 
tendon.  The  latter  and  the  ligaments 
have  no  nerves  or  lymphatics.  The 
vessels  of  a  tendon  of  an  ostrich  are 
shown  by  Fig.  176.  The  manner  of 
union  between  tendon  and  muscle,  and 
further  particulars  in  regard  to  the 
tendons,  will  be  explained  in  the  chap- 
ter on  "Striated  Muscular  Tissue." 

2.  Aponeuroses  are  composed  of  fas- 
ciculi of  white  fibrous  tissue,  so  inter- 
woven as  to  form  a  membraniform  ex- 
pansion of  varying  thickness.  If  very  thin,  no  vessels  are  sent 
among  the  fasciculi,  but  only  to  the  areolar  sheath  in  contact  with 
each  surface.  If  thick,  the  vessels  penetrate  between  the  fasciculi 
in  an  irregular  manner.  Aponeuroses  are  found  at  the  origins  of 
muscles,  as  the  tendons  constitute  their  insertion.  They  also  exist 
distinctly  from  muscles,  as  in  the  case  of  the  deep  fascia  of  the 
extremities  (femoral  and  brachial  aponeurosis,  &;c.). 

3.  Fihro-cartilages  have  the  same  structure  as  tendons  and  liga- 
ments, except  that  cartilage-cells  are  scattered  among  the  bundles 
of  white  fibrous  tissue,  and  that  they  contain  no  finer  elastic  fibres. 
Fig.  202  represents  a  section  of  fibro-cartilage.  They  exist  as  spe- 
cial organs  (interarticular  fibro-cartilages  and  the  cotyloid  liga- 


«.  Vessels  of  the  tendon  of  an  ostrich. 
6,  c.  Vessels  of  muscle  and  tendon,  unit 
ingateJ.  (Qti^ekett.) 


WUITE   FIBROUS   TISSUE. 


279 


ments),  or  are  found  developed  in  the  tendons,  tendinous  sheaths, 
and  the  ligaments. 

4.  The  fibrous  membranes^  so  called,  differ  from  the  tendons  only 
by  the  frequent  interweaving  of  the  bundles,  to  give  them  their 
difference  in  form,  and  by  the  greater  amount  of  elastic  fibres. 
Under  this  head  may  be  mentioned — 

First.  The  deep  fascioe.  (femoral,  &c.),  which  very  nearly  resemble 
the  aponeuroses  in  structure,  and  some  of  which  are  classed  with 
them. 

Secondly.  The  2-)eriosteuni  and  perichondrium^  which  sometimes 
contain  a  great  number  of  elastic  fibres,  are  more  vascular  than 
the  preceding,  and  are  sparingly  supplied  with  nerves  and  lymph- 
atics. The  dura  mater  also  belongs  here,  it 
being  the  internal  periosteum  (endosteum)  of 
the  cranium,  while  it  at  the  same  time  protects 
the  encephalon. 

5.  The  white^  dense  tunics  included  under  the 
second  head,  except  the  cornea — viz :  the  fibrous 
tunic  of  the  testes  and  ovaries,  penis  and  clitoris, 
and  the  fibrous  envelop  of  the  spleen  and  kid- 
neys— consist  of  solid  white  fibrous  tissue,  with 
elastic  fibres  interwoven.  In  the  case  of  these 
organs,  also,  the  fibrous  layer  projects  into  the 
interior,  where,  mixed  to  a  greater  or  less  ex- 
tent with  smooth  muscular  fibres,  it  constitutes 
dissepiments  or  a  kind  of  framework,  or  forms 
a  stroma  or  a  trabecular  network.  The  object 
here  is  to  inclose  and  protect  the  parenchyma 
of  the  organs  in  question.  The  sclerotica,  how- 
ever, has  no  such  internal  projections ;  and  the 
perineurium  is  homogeneous  in  structure,  as 
has  been  already  stated  (p.  276).  Fig.  177  shows  the  fibrous  tra- 
beculee  in  the  testis,  radiating  from  the  mediastinum. 

6.  The  so-called  vascular  Tnembranes — the  pia  mater,  choroid 
plexus,  the  choroid  coat  of  the  eye,  and  the  iris — all  have  numerous 
vessels ;  for  the  nutrition,  however,  especially  of  other  parts.  The}' 
vary  in  structure.  The  iris  and  the  pia  mater  have  parallel,  matted, 
and  anastomosing  bundles  of  white  fibres,  without  any  elastic  tis- 
sue.    The  choroid  plexus  and  the  choroid  membrane  of  the  eye, 


Section  of  testis.  1.  Ca- 
vity of  tunica  vaginalis.  2. 
Tunica  albuginea.  3.  Medi- 
astinum testis,  givingoff  the 
trabecalie  ;  between  wMct 
are  tlie  lobules  (.5)  of  semi- 
niferous tubes.  4.  Pia  ma- 
ter testis.  6.  Epididymis, 
and  below  it  the  corpus 
Highmorianum,  above  3. 


280 


THE   TISSUES, 


liave  a  homogeneous  tissue  like  tlie  perineurium,  to  which  the  pecu- 
liar anastomosing  pigment-cells,  described  on  page  133,  are  added. 

7.  Structure  of  the  cornea. — The  true  cornea  is  to  be  included  his- 
tologically under  white  fibrous  tissue;  though  in  chemical  compo- 
sition it  is  allied  to  cartilage,  since  it  affords  chondrine,  and  not 
gelatine  on  boiling. 

The  cornea  considered  as  a  whole,  consists  of  five  layers:  1,  the 
true  lamellaied  cornea;  2,  3,  the  anterior  and  posterior  elastic  layers, 
and  4,  5,  the  anterior  (external),  and  posterior  (internal)  epithelium. 
The  anterior  epithelium  consists  of  three  or  four  strata  of  cells,  and 
the  posterior  of  one.  The  anterior  and  the  posterior  elastic  layers 
are  merely  basement-membranes  underlying  the  epithelia.  The 
posterior  is  called  the  "  membrane  of  Demours."  The  anterior  is 
bound  to  the  lamellated  cornea  by  fine  elastic  fibres,  while  the  pos- 
terior is  not.  The  former  is  probably  what  remains  of  the  vascular 
conjunctiva  covering  the  cornea  of  the  foetus. 

But  the  true  cornea  (lamellated  cornea,  Todd  and  Bowman),  con- 
stitutes the  greater  part  of  the  substance  of  this  organ.  This  con- 
sists of  about  sixty  superimposed  lamellee,  composed  of  transparent 
fibres  interwoven  so  as  to  leave  tubular  spaces'  between  them,  and 
is  continuous  with  the  white  fibrous  tissue  of  the  sclerotica.  These 
tubular  interspaces  are  arranged  with  tolerable  regularity  and  con- 
stricted at  intervals,  as  shown  by  Fig.  178.  This  lamellated  tissue 
is  the  only  portion  of  the  cornea  which  is  continuous  with  the 

Fig.  178. 


"^^^ 


Tubes  of  the  cornea  proper,  as  sliowu  in  the  eye  of  the  ox,  by  mercurial  injection.    Slightly 

niaguified. 

sclerotica,  and  its  fibres  appear  similar  to  those  of  the  latter,  except 
that  they  are  transparent  {7 odd  and  Bowman).     Their  continuity  is 


'  KoUiker,  however,  believes  these  tubes  are  artificial  dilatations  by  injection 
between  the  transparent  fibres. 


WHITE   FIBllOUS   TISSUE. 


281 


shown  by  Fig.  179.     The  tubular  interspaces  are  doubtless  filled 
witli  a  transparent  fluid.    JSTo  vessels  extend  into  the  substance  of 

Fig.  179. 


Vertical  section  of  the  sclerotic  and  cornea,  showing  the  continuity  of  their  tissue  between  the 
dotted  lines,  a.  Cornea.  6.  Sclerotica.  In  the  cornea,  the  tubular  spaces  are  seen  cut  through,  and 
in  the  sclerotic  the  irregular  areola;.  Cell-nuclei,  as  at  c,  are  seen  scattered  throughout,  rendered 
more  distinct  by  acetic  acid.    (Magnified  320  diameters.) 

the  cornea.  Those  of  the  sclerotica  form  loops  extending  to  its 
margin,  as  shown  by  Fig.  180,  Some  superficial  branches  belong- 
ing to  the  conjunctiva  extend,  however, 
in  front  of  the  cornea  to  the  distance 
of  I  to  |-  of  a  line  from  its  margin,  as 
seen  in  the  figure.  It  is  suggested  by 
Kolliker  that  vessels  carrying  the  li- 
quor sanguinis  alone,  may  communi- 
cate with  these,  and  extend  through- 
out the  cornea. 

That  the  fluid  in  the  tubular  inter- 
spaces is  the  blood-plasma,  may  be  in- 
ferred from  the  fact  that  though  there 
are  no  vessels  in  the  cornea,  incised 
wounds  heal  very  readily.  This  is  the 
case  usually  after  the  removal,  of  cata- 
ract by  extraction.  Since  the  plasma 
must,  however,  be  afforded  by  the  pe- 
rimetral  vessels,  it  is  important  not  to 
carry  the  incision  further  round  than 
is  actually  necessary. 

In  diseased  conditions  of  the  cornea,  however,  the  deep-seated 

vessels  may  be  prolonged  into  its  entire  substance,  while  the  super- 


Nutricut  vessels  of  the  cornea,  a.  Su- 
perficial vessels  belonging  to  the  con- 
junctival membrane,  and  continued 
over  the  margin  of  the  cornea,  b.  Ves- 
sels of  the  sclerotic  returning  at  the 
margin  of  the  cornea. 


282  THE   TISSUES. 

ficial  form  a  dark  band  of  considerable  breadth  around  its  margin. 
Opacity  very  frequently  results  from  the  organization  of  plasma  in 
the  tubular  interspaces,  and  between  the  lamina3;  the  new  forma- 
tion not  being  transparent  like  the  original  tissue. 

The  arcus  senilis^  occurring  mostly  in  aged  persons,  results  from 
a  fatty  degeneration  of  the  cornea. 

Distribution  of  White  Fibrous  Tissue  in  the  Lower  Animals. 

This  tissue  is  found  in  all  vertebrate  animals  in  about  the  same 
conditions  as  in  man;  while  in  the  invertebrata  it  is  very  rare.  In 
mollusca  the  tendinous  fibres  are  very  large;  in  the  terebratula, 
even  -^^-^  of  an  inch  in  diameter,  and  collected  into  strong  bundles 
presenting  a  beautiful  silvery  aspect.  In  birds,  the  tendons  of  the 
legs  are  very  large,  and  more  or  less  ossified.  Every  one  has 
noticed  this,  especially  in  the  case  of  the  turkey,  goose,  and  other 
species  most  frequently  used  as  food.  The  analogy  of  this  tissue 
to  bone,  in  a  chemical  point  of  view,  has  already  been  suggested 
(p.  276),  and  will  account  for  its  tendency  to  ossification. 

Development  of  White  Fibrous  Tissue, 
Bonders  and  Virchow  coincide  in  the  opinion  that  the  true  white 
fibrous  tissue  (the  gelatinous  intercellular  tissue  of  white  fibrous 
tissue,  bones,  and  teeth),  does  not  originate  from  cells,  but  is  directly 
separated  from  a  plastic  fluid ;  while  the  other  elements — lacunas 
and  pores,  cartilage-cells,  and  nuclear  (elastic)  fibres — are  primarily 
formed  from  cells.  Kolliker  thinks  differently  as  to  the  develop- 
ment of  the  fibres  of  white  fibrous  tissue ;  asserting  that  the  nuclear 
fibres  are  developed  not  from  the  nuclei  of  the  cells  of  the  white 
fibrous  tissue  of  the  embryo,  but  from  the  cell-walls;  while  the 
cell-contents  are  converted  into  the  collagenous  element,  or  white 
fibrous  tissue. 

We  agree  with  Reichert  and  Virchow  that  the  elastic  fibres 
blended  with  the  collagenous  element,  or  true  white  fibrous  tissue, 
represent  the  cells  of  cartilage;  while  the  white  fibrous  tissue  re- 
presents the  matrix  or  homogeneous  substance  of  cartilage;  and, 
like  the  latter,  is  not  developed  from  cells.  This  view  is  confirmed 
by  an  examination  of  the  insertion  of  tendons  into  bones  in  young 
animals,  and  in  which  the  surface  of  the  latter  is  still  in  a  state  of 
cartilage. 

The  white  fibrous  tissue  alone  has  been  confounded  with  the 
areolar,  under  the  name  of  the  connective  tissue.  Kcilliker's  "  areo- 
lated  connective  tissue"  is  the  true  areolar  tissue,  and  will  be  de- 


WHITE   FIBROUS   TISSUE.  283 

scribed  in  the  following  chapter.  Cells  appear  to  perform  an  im- 
portant part  in  the  development  of  the  latter  tissue,  as  will  be  seen. 
But,  for  the  present,  we  may  adopt  the  view  wliich  regards  the 
elastic  fibres  as  developed  from  cells,  while  the  collagenous  element, 
or  white  fibrous  tissue,  is  at  first  formed  directly  from  the  plasma. 

The  groictli  of  white  fibrous  tissue  is  secured  by  a  gradual  in- 
crease of  the  bundles  before  described;  and  this  occurs  probably 
from  the  plasma  directly — each  fasciculus  assimilating  to  itself  the 
amount  required. 

The  reparation  of  this  tissue,  if  inflammation  occurs,  is  imperfect; 
e.  g.  if  a  portion  of  a  tendon  be  removed,  or  if  the  ends  of  a  divided 
tendon  be  separated  (as  in  operations  for  club-foot),  the  new  tissue 
is  similar  to  white  fibrous  tissue ;  but  is  developed  from  cells,  and 
is  a  condensed  form  of  areolar  tissue,  rather.  If  inflammation  does 
not  occur,  the  exuded  plasma  is  directly  (i.  e.  without  the  interme- 
diation of  cells),  converted  into  a  collagenous  tissue  precisely  iden- 
tical with  the  original  development. 

Pathological  Slates  and  New  Formations  of  the  White  Fibrous  Tissue. 

1.  It  is  difficult  to  distinguish  between  a  new  formation  and  a 
hypertrophy  of  the  white  fibrous  tissue,  if  the  change  occurs  in  a 
part  or  organ  in  which  this  tissue  naturally  exists,  A  hypertrophy, 
so  called,  of  the  capsule  of  Glisson  produces  the  granular  liver,  or 
cirrhosis;  and  hypertrophy  of  the  collagenous  tissue  between  the 
tubes  in  the  kidney,  produces  the  granular  kidney,  or  one  form  of 
Bright's  disease.  In  both  these  cases,  the  parenchymal  substance 
is  diminished  by  the  pressure  consequent  on  the  increase  of  this 
interstitial  element. 

2.  This  tissue  is  also,  like  all  others,  liable  to  atrophy,  if  its  usual 
supply  of  blood  be  cut  oft";  as  by  pressure  upon  the  vessels  by 
tumors,  aneurisms,  &c, 

3.  Pathological  new  formations  of  this  tissue  are  very  common, 
and  constitute  many  of  the  pathological  epigeneses.  Fibroid  tumors 
of  the  uterus  are  often  formed  of  it  without  any  admixture  of  the 
elastic  element.  Condylomata,  warts,  and  vegetations  on  the  skin 
and  the  raucous  and  serous  membranes,  are  essentially  new  forma- 
tions of  collagenous  tissue,  usually  covered  by  a  distinct  epithelium 
(p.  247).  The  walls  of  cysts  are  formed  of  white  fibrous  tissue,  as 
well  as  most  of  the  substance  of  nasal,  laryngeal,  and  uterine 
polypi;  though  in  all  these  cases,  the  loose  arrangement  of  the  fibres 
may  rather  entitle  it  to  the  name  of  areolar  tissue.  The  same  re- 
mark may  also  be  extended  to  najvi  raaterni. 

Sarcomatous  tumors  are  formed  in  great  part  of  this  tissue.  The 
Jcehides  is  also  a  development  of  it  in  the  corium  of  the  skin,  giving 


28-i  THE   TISSUES. 

rise  to  an  appearance  like  a  cicatrix.  Even  the  lupus  exedens  is 
merely  a  development  of  white  fibrous  tissue  in  the  corium  of  the 
skin;  but  in  such  a  way  as  to  cause  atrophy  and  ulceration  of  its 
structure,  and  thus  its  progressive  destruction. 

The  pathological  development  of  white  fibrous  tissue  alone,  is 
not  generally  regarded  as  producing  a  malignant  epigenesis.  But 
this  distinction  of  malignant  and  non-malignant  is  evidently  of  less 
importance,  when  we  consider  that  the  atrophy  of  the  parenchyma 
of  the  liver  from  a  hypertrophy  of  Glisson's  capsule,  is  as  sure  to 
be  fatal  if  it  continues  to  progress,  as  is  any  form  of  cancerous 
development. 


CHAPTER    IV 


THE   AREOLAE  TISSUE. 


Several  different  terms  have  been  used  by  different  histologists 
to  designate  this  tissue.  Long  ago  termed  the  cellular  tissue,  it  has 
more  recently  been  called  the  connective  tissue ;  the  reticulated  con- 
nective tissue  {Kdlliker) ;  the  fibro-cellular  tissue ;  the  fibrous  cellu- 
lar {HassalT),  and  the  areolar  tissue  {Todd  and  Boiuman).  Of  all 
these,  the  last  is  the  only  appropriate  name.  The  term  "  connective," 
as  applied  to  any  tissue  has  already  been  objected  to  (p.  275),  though 
it  is  really  more  applicable  to  this  than  to  any  other,  as  expressing 
one  of  its  functions.  By  a  cellular  tissue  can,  now-a-days,  be  meant 
only  a  tissue  composed  of  an  aggregation  of  cells,  like  the  epithe- 
lium, &c. ;  and  by  a  fibro-cellular,  one  composed  of  fibres  and  cells. 

The  tissue  under  consideration  is  composed  of  fibres  so  inter- 
woven, either  separately  or  in  fasciculi,  as  to  leave  larger  or  smaller 
irregular  spaces — areolce — between  them.  And  this  arrangement 
constitutes  the  peculiarity  of  the  tissue ;  for  the  fibres  are  those  of 
the  white-fibrous  tissue  and  the  yellow-fibrous  tissue,  just  described. 
It  has  been  seen  that  white-fibrous  tissue  is  almost  invariably  ac- 
companied by  the  yellow,  as  in  the  tendons,  fibrous  membranes, 
&c.  (p.  278).  But  while  in  these  the  elastic  element  exists  only  in 
a  very  small  amount,  and  both  are  so  intimately  blended  as  to  form 
a  very  compact  structure ;  in  the  areolar  tissue  the  elastic  element 
is  more  abundant,  and  the  areola)  give  rise  to  a  loose  and  spongy 
tissue.     A  description  is,  therefore  required : — 


THE   AREOLAR  TISSUE. 


285 


1.  Of  the  solid  fibrous  tissues. 

2.  The  areolae  and  their  contents. 

1.  The  collagenous  element  (white-fibrous  tissue)  of  the  areolar 
tissue  always  greatly  predominates  over  the  elastic  element,  though 
varying  in  its  precise  proportional  amount  in  different  parts  and 
organs.  It  occurs  in  fasciculi,  as  shown  in  Fig.  181,  of  a  more  or 
less  wavy  outline,  and  of  various  length  and  size;  they  frequently 
being  about  g -J  „  of  an  inch  in  diameter.  Among  these  the  elastic 
fibres  are  distributed,  sometimes  in  bundles,  but  more  frequently 

Fig.  181. 


The  two  elements  of  the  areolar  tissue,  in  their  natural  relations.  1.  The  white  fibrous  element, 
with  cell-nuclei  (9)  sparingly  visible  in  it.  2.  The  yellow  fibrous  element,  showing  the  branching 
or  anastomosing  character  of  its  fibres.  3.  Fibres  of  the  elastic  element,  much  finer  than  the  rest. 
8.  Nucleolated  cell-nuclei,  often  seen  apparently  loose.     (Magnified  320  diameters.) 


single,  and  being  ^oVo  to  gx)V(T  of  ^n-  i^^h  in  diameter.  Frequently 
also  they  are  coiled  around  the  other  fasciculi,  as  shown  in  the 
figure.  Messrs.  Todd  and  Bowman  first  called  attention  to  the 
fact  that  this  tissue  is  a  compound  of  the  two  just  mentioned.  The 
elastic  fibres  are  easily  isolated  from  the  white  fibrous  tissue  under 
the  microscope,  by  the  action  of  acetic  acid;  which  renders  the 
latter  indefinable,  soft,  and  gelatinous  (pp.  270  and  277). 

2.  The  areolce  are  merely  irregular  cavities  between  the  solid 


286 


THE   TISSUES. 


Fig.  182. 


elements,  just  described.  (Fig.  182.)  They  consequently  have  no 
distinct  walls,  and  they  freely  communicate  with  each  other.  Their 
size  varies  extremely;  sometimes  occupying  much  more  space  in 
the  aggregate  than  the  solid  portions,  in  which  case  the  tissue  is 
very  loose ;  while  in  other  cases  they  are  very  small,  from  a  con- 
densation of  the  fibres  around  them.     It  is  this  free  communication 

which  accounts  for  the  ready  diffusion 
of  blood  and  other  fluids  in  the  areolar 
tissue  under  the  influence  of  gravity. 
The  smallest  meshes,  however,  in  some 
parts  are  so  disposed  as  to  constitute 
secondary  cavities  of  a  somewhat  de- 
terminate shape  and  size,  and  which 
are  visible  to  the  naked  eye.  These 
generally  contain  fat-cells;  and  the 
much-branched,  sometimes  tubular, 
"AWii^'W^  \  ^^^HUf"-^  sometimes  fissure-like  spaces  connect- 
)\Jli!(lS^ail4^!^MRlll'/  ing  them,  are  termed  the  areolar  pas- 

sages. 

The  contents  of  the  areola  are :  (1),  a 
fluid  of  an  alkaline  reaction,  resem- 
bling a  weak  serum ;  or  (2),  fat-cells. 
This  fluid  is  a  mere  transudation,  and 
not  a  secretion,  from  the  bloodvessels 
traversing  the  tissue,  and  its  general 
composition  has  been  specified  on  page 
181.  In  some  parts,  however,  the  areolce  are  partly  or  entirely  filled 
by  fat-cells;  in  which  case  the  serous  fluid  is  proportionately  ex- 
cluded. This  is  especially  the  case  with  the  subcutaneous  areolar 
tissue,  or  sxiperficial  fascia.  But  in  certain  parts,  fat  never  accu- 
mulates; as  underneath  the  skin  of  the  eyelids,  of  the  scrotum,  &c. 
The  amount  of  fluid  in  the  areolas  is  liable  to  sudden  increase  or 
diminution,  often  from  slight  causes;  the  former  producing  oedema 
or  swelling,  and  the  latter  a  shrivelled  appearance  of  the  skin  over 
the  part  in  which  it  occurs. 

Sometimes  the  areolae  become  filled  to  a  greater  or  less  extent 
with  air,  to  the  exclusion  of  the  fluid.  Occurring  as  a  pathological 
condition  it  constitutes  emphysema.  This  may,  indeed,  be  produced 
with  the  blowpipe  experimentally ;  and  Bichat  tells  of  mendicants 
who   excite  the  commiseration  of  passers-by,  by  the  singular  ap- 


portion of  areolar  tissue,  inflated  and 
dried,  showing  t)ie  general  character  of 
its  larger  meshes.  Each  lamina  and  fila- 
ment here  represented,  contains  numer- 
ous smaller  ones,  matted  together  by  the 
mode  of  preparation.  (Magnified  20  dia- 
meters.) 


THE   AREOLAK  TISSUE. 


287 


pearance  produced  by  inserting  a  quill  under  the  skin  of  the  chest, 
and  blowing  forcibly  through  it — a  general  emphysema  being  thus 
promptly  produced.  The  air  is,  however,  removed  by  absorption 
within  a  few  hours  without  any  injurious  results.  This  experiment 
also  demonstrates  the  free  communication  of  the  areoke  with  each 
other  over  the  whole  body  even. 

Chemical  Gomposilion  of  Areolar  Tissue. 
Areolar  tissue  abounds  in  water,  since  its  serous  fluid  consists 
mostly  of  it.  Besides,  both  the  white  and  the  yellow  fibrous  tis- 
sues contain  a  considerable  percentage  of  it.  Of  course,  giutin  is 
obtained  from  areolar  tissue  by  boiling;  from  the  osteine  contained 
in  its  white  fibrous  tissue.  Elasticine  exists  in  the  elastic  tissue. 
In  addition  to  these,  we  have  only  to  refer  to  the  composition  of 
the  transudations  for  the  amount  of  albumen  and  saline  matters 
they  contain  (p.  182). 

Properties  of  Areolar  Tissue. 

Areolar  tissue  has  no  characteristic  vital  properties,  since  this  is 
the  fact  with,  regard  to  both  of  its  two  component  elements.  Like 
them  it  is  distinguished  by  physical  properties  merely;  the  princi- 
pal being  extensibility  and  elasticity,  with  a  good  degree  of  strength. 
It  owes  the  last  property  to  the  collagenous  element,  and  the  other 
two  to  the  elastic  tissue.  If  it  be  asked  how  a  tissue  formed  in 
great  part  of  an  entirely  inextensible  element  (the  white  fibrous 
tissue),  becomes  extensible,  we  have  to 
remember  that  in  extending  the  areolar 
tissue  the  individual  fasciculi  of  white 
fibrous  tissue  are  not  stretched,  but  are 
merely  displaced  upon  each  other;  while 
the  elastic  fibres  restore  them  to  their 
original  relations  after  the  tension  is  re- 
moved. 

The  only  vital  property  manifested  by 
this  tissue  is  the  one  common  to  all  the 
tissues  mentioned  thus  far;  viz.,  the  power 
of  maintaining  its  own  nutrition.  The 
nutritive  changes  are,  however,  probably 
but  slowly  brought  about,  after  it  is  once  fully  developed,  and  the 
vessels  in  its  substance  are  mostly  on  their  way  to  other  tissues. 


Fiff.  183. 


Vessels  of  areolar  tissue  from  the 
neckof  a  youngpig.  a,  a.  Nerves. 
(QueclieU.) 


288  THE   TISSUES. 

ISTor  can  the  nerves  detected  in  it  be  regarded  as  belonging  to  it, 
since  they  proceed  beyond  to  terminate.  Consequently,  it  mani- 
fests but  a  slight  degree  of  sensibility  when  divided  by  the  sur- 
geon's knife.  The  vessels  in  areolar  tissue  are  generall}^  arranged 
so  as  to  include  hexagonal  spaces,  as  seen  in  Fig.  183,  from 
Queckett ;  and  which  also  shows  the  appearance  of  the  nerves. 

Uses  of  Areolar  I'issue. 
The  functions  of  areolar  tissue  depend  on  the  physical  properties 
just  mentioned. 

1.  It  isolates  the  various  organs  by  constituting  their  external 
envelop. 

2.  It  at  the  same  time  lies  between  and  connects  the  various 
organs  together  in  the  body,  and  yet  so  as  to  allow  of  a  certain 
amount  of  motion  of  one  upon  another.  It  is,  therefore,  the  true 
connective  tissue  (p.  275). 

3.  It  protects  the  proper  substance  or  parenchyma  of  various 
organs. 

4.  It  gives  support  to  organs,  and  maintains  them  in  their  place. 
Thus,  with  few  exceptions,  it  accompanies  the  bloodvessels  and 
nerves  to  their  minutest  subdivisions. 

It  must,  therefore,  be  regarded  as  a  subordinate  tissue,  wherever 
found,  though  quite  indispensable  on  account  of  the  mechanical 
uses  just  described. 

Distribution  of  the  Areolar  Tissue. 
The  areolar  is  more  extensively  diffused  than  any  other  tissue  in 
the  body.  Indeed,  it  enters  to  such  an  extent  into  the  structure  of 
every  part  and  organ,  with  very  few  exceptions,  that  if  all  the  other 
tissues  were  entirely  removed  from  the  body,  its  conformation  would 
still  be  preserved  in  every  part  by  the  areolar  tissue ;  and,  except 
from  the  removal  of  the  osseous  and  the  muscular  tissues,  its  weight 
would  be  but  slightly  diminished,  as  the  following  particulars  will 
show : — 

1.  It  surrounds  and  supports  the  arteries  and  veins  everywhere, 
and  sometimes  the  capillaries  also,  and  thus  enters  with  the  vessels 
into  every  organ. 

2.  It  also  forms  sheaths  (perineuria)  around  all  the  nerves ; 
accompanying  them,  however,  to  their  finest  ramifications,  in  an 
undeveloped  form  (p.  276).     The  brain,  however,  does  not  contain 


THE   AREOLAR   TISSUE.  289 

it,  except  as  it  surrounds  the  vessels,  two  or  three  removes  from 
the  capillaries. 

3.  Areolar  tissue  invests  the  muscles  externally,  forming  their 
sheaths  or  perimysia^  which  give  off  prolongations  (internal  peri- 
mysia)  investing  the  fasciculi  of  fibres.  The  heart,  however,  con- 
tains this  element  in  very  small  proportion,  its  fibres  intertwining 
in  such  a  manner  as  to  render  an  extraneous  bond  of  connection 
unnecessary.  It  also  lies  between  and  underneath  the  muscles,  and 
in  greater  quantity  in  proportion  to  the  required  mobility. 

4.  This  tissue  is  abundant  around  internal  organs  which  undergo 
changes  of  form,  size,  or  position  in  the  performance  of  their  func- 
tions, and  which  are  partially  or  wholly  without  a  free  surface,  as 
the  pharynx,  oesophagus,  bladder,  lumbar  colon,  &c.;  and  its  fila- 
ments are  long,  tortuous,  and  largely  intertwined.  It  also  envelops 
all  the  glands,  and  sends  prolongations  into  their  interior  among 
their  lobules;  it  being  more  abundant  in  proportion  as  the  gland  is 
less  compact,  and  allowing  motion  of  one  part  upon  another.  E.  g. 
it  is  far  more  abundant  in  the  mammary  gland  than  in  the  liver. 

5.  Under  the  skin  and  the  mucous  and  serous  membranes,  it 
forms  a  distinct  layer,  though  presenting  great  varieties  in  respect 
to  quantity  and  denseness. 

6.  Finally,  the  corium  of  the  skin  and  of  mucous  and  serous 
membranes  is  merely  condensed  areolar  tissue,  as  will  be  seen. 

Peculiarities  of  Areolar  Tissue. 

A  peculiar  form  of  areolar  tissue  is  said  by  Henle  to  exist  in 
company  with  the  arteries  at  the  base  of  the  brain;  the  elastic  fibres 
forming  rings  and  spirals  around  the  fasciculi  of  the  white  fibrous 
tissue. 

The  subcutaneous  areolar  tissue  is  also  of  peculiar  practical  im- 
portance, and  will  therefore  receive  some  additional  notice  here. 

The  Subcutaneous  Areolar  Tissue. 
The  layer  of  areolar  tissue  under  the  skin  was  formerly  called 
the  cellu.lar  membrane.  It  is  \)TO-pev\y  icvmed  the  superjicial  fascia, 
or  the  subcutaneous  areolar  tissue.  It,  singularly  enough,  is  de- 
scribed by  Kcilliker  as  one  of  the  layers  of  the  skin  itself;  and 
whenever  it  contains  fat-cells  in  its  areolse,  it  is  by  him  called  the 
panniculus  adiposus.  He  also  restricts  the  term  superficial  fascia  to 
19 


290  THE   TISSUES. 

its  innermost  layer,  where,  as  upon  tlie  trunk,  thighs,  &c.,  it  forms  a 
tolerably  firm  texture  without  fat-cells. 

The  inner  surface  of  the  subcutaneous  areolar  tissue  is  most  loosely 
adherent  to  the  subjacent  parts  upon  the  trunk,  the  forearms,  legs, 
the  back  of  the  hands  and  feet,  the  eyelids,  penis,  and  scrotum,  and 
on  the  extensor  side  of  the  articulations.  A  closer  connection  exists 
where  tendinous  fibres  or  processes  are  inserted  into  the  skin  (leva- 
tor labii  superioris,  palmaris  brevis,  &c.);  and  where  this  tissue  is 
connected  with  subjacent  muscles  by  short,  strong  filaments  of 
white  fibrous  tissue,  as  on  the  head,  alae  nasi,  and  lips,  the  forehead 
and  temples,  the  ear,  mouth,  and  occiput;  also  on  the  glans  penis, 
beneath  the  nails,  &c.  Generally  the  skin  is  less  movable  where 
the  fat  forms  a  thick  layer,  than  where,  from  any  reason,  it  is  less 
abundant,  or  entirely  absent. 

The  external  surface  of  the  subcutaneous  areolar  tissue  is  con- 
nected by  numerous  filamentous  processes  of  white  fibrous  tissue 
with  the  corium  of  the  skin,  and  is  not  everywhere  distinct  from 
the  latter,  as  under  the  skin  of  the  penis  and  scrotum  (dartos). 
Generally,  however,  the  areolar  tissue  is  pretty  easily  separable 
from  the  skin,  especially  where  the  former  contains  an  abundance 
of  fat ;  except  where  the  follicles  of  the  larger  and  more  closely-set 
hairs  penetrate  deeply  into  the  fat,  as  on  the  head,  cheeks,  chin,  &c. 

The  thickness  of  the  subcutaneous  areolar  tissue  varies  much  in 
various  situations.  That  of  the  eyelids  and  the  upper  and  outer 
part  of  the  ear  is  Jg  of  an  inch  thick ;  of  the  penis,  3'g ;  and  of  the 
scroturii,  j'g  of  an  inch.  [Krause)  In  these  situations  there  is  no 
fat;  in  those  next  mentioned  there  is.  On  the  cranium,  brow, 
nose,  lobe  of  the  ear,  back  of  the  hand  and  foot,  the  knee  and  elbow, 
the  thickness  is  1  line,  while  in  most  other  situations  it  is  ^  to  \  of 
an  inch  thick.  The  thickness,  however,  in  the  same  part,  varies 
with  the  age,  sex,  and  the  individual.  Women  have  more  fat  in  its 
areoke,  generally,  than  men;  and  hence  a  greater  thickness  of  this 
layer,  as  well  as  a  greater  plumpness  of  form.  It  is  thicker,  pro- 
portionally, in  healthy  infants  and  children  than  during  adolescence. 
In  corpulent  persons  the  subcutaneous  areolar  tissue  may  become 
so  laden  with  fat  as  to  be  4  inches  thick  even;  while  in  lean  per- 
sons, in  the  same  situation,  it  may  not  exceed  1  line. 

Similar  extremes  in  thickness  may  also  present  themselves  in  the 
same  person  on  passing  from  a  state  of  emaciation  to  one  of  corpu- 
lence, or  the  reverse.     And  this  is  a  fact  of  great  practical  import- 


THE   AREOLAR   TISSUE.  291 

ance  to  the  surgeon,  especially  in  regard  to  the  making  of  incisions 
preliminary  to  the  ligation  of  arteries.  It  is,  of  course,  only  in 
situations  where  the  areolas  are  large,  and  filled  with  fat-cells,  that 
these  changes  occur;  as  on  the  abdomen,  the  neck,  and  the  limbs  espe- 
cially. It  less  affects  the  back  of  the  trunk,  since  there  the  tissue 
is  much  more  condensed,  and  the  areola?  are  therefore  very  small. 

Development  of  Areolar  Tissue. 

In  the  earliest  period  at  which  the  areolar  tissue  can  be  examined, 
Schwann  has  described  it  as  consisting  of  nucleated  particles,  send- 
ing offsets  on  the  opposite  sides,  and  uniting  themselves  with  others 
in  the  vicinity.  The  threads  thus  formed  are  at  first  homogeneous; 
the  longitudinal  streaks  and  the  wavy  character  appear  subsequently. 
Normally  and  originally,  however,  we  believe  that  the  yellow  fibrous 
element  alone  is  developed  from  cells  (p.  283). 

The  development  of  areolar  tissue  consists,  in  fact,  merely  of  the 
simultaneous  development  of  the  white  and  the  yellow  fibrous  tis- 
sues in  the  same  blastema.  These  elements  subsequently  become 
blended,  as  found  in  the  different  situations  already  described. 

When  new  formations  of  areolar  tissue  occur,  however,  as  in  in- 
flammatory exudations,  subcutaneous  wounds,  &c.,  the  white  fibrous 
element  may  be  developed  either  from  cellfe  or  directly  from  the 
plasma,  as  has  been  shown  by  Mr.  Paget. 

1.  In  case  of  repair  by  granulation,  and  of  inflammatory  adhe- 
sions and  indurations,  the  white  fibrous  element  of  the  areolar  tissue 
is  developed  from  cells.  "The  cells  first  formed  in  the  plastic  exu- 
dation are  round,  very  slightly  granular,  and  from  T5V0  ^^  jo'nu  of 
an  inch  in  diameter;  they  have  a  distinct  cell- wall,  which  is  readily 
brought  into  view  by  the  action  of  water,  if  not  apparent  at  first : 
and  they  present  a  round,  dark-edged  nucleus,  whose  sharp  defini- 
tion distinguishes  it  from  that  of  the  colorless  corpuscles  of  the 
blood,  to  which  these  cells  otherwise  bear  a  close  resemblance.  It 
is  in  this  nucleus  that  the  first  developmental  change  shows  itself, 
for  it  assumes  an  oval  form,  and  its  substance  becomes  clearer  and 
brighter.  Very  soon,  however,  the  cell  itself  elongates  at  one  or 
both  ends,  so  as  to  assume  the  caudate,  fusiform,  or  lanceolate  shape 
(Fig.  184);  and  its  contents  become  more  minutely  and  distinctly 
granular,  whilst  the  cell-wall  thins  away,  or  becomes  blended  with 
its  inclosure.  As  the  cells  elongate  more  and  more,  so  as  to  assume 
the  filamentous  form,  they  also  arrange  themselves  in  such  a  manner 


2y2 


THE    TISSUES. 


Fig.  184. 


that  the  thickest  portion  of  oue  is  engaged  between  the  thinner  ends 
of  the  two  or  more  adjacent  to  it;  and  thus  fasciculi  are  gradually 
formed,  of  which  every  fibre  is  developed  from 
one  elongated  cell,  except  where  two  or  more 
cells  have  united  end  to  end,  so  as  to  form  one 
long,  continuous  filament.  In  the  production 
of  areolar  tissue  in  inflammatory  exudations, 
or  in  granulating  wounds,  the  nuclei  of  these 
fibre-cells  appear  to  waste  and  be  absorbed; 
but  in  the  normal  course  of  development,  which 
may  be  seen  to  take  place  on  this  plan  in  the 
subcutaneous  areolar  tissue  of  the  foetus,  as 
well  as  in  many  other  situations,  it  is  probable 
that  they  develop  themselves  into  the  'nuclear 
Development  of  fibres  from    fibres'  of  Hculc,  which  coustitute,  iu  fact,  the 

cells,    a  Circular  or  oval  nu-  i         •        m  i 

yellow  or  elastic  tilaments  that  are  intermin- 
gled with  the  white  in  this  tissue'"  (p.  273). 

2.  In  case  of  the  filling  up  of  subcutaneous 
wounds,  as  of  tendons  especially,  the  white 
fibrous  element  is  formed  directly  by  ihe  fibril- 
lation of  a  nucleated  blastema.  This,  when  first  effused,  "seems  like 
a  mere  fibrinous  exudation,  usually  containing  a  quantity  of  finely- 
molecular  or  dimly-shaded  substance,  but  having  no  appearance  of 
distinct  nuclei;  these,  however,  gradually  present  themselves  in  it, 
as  oval  bodies,  with  dark,  hard  outlines,  which  soon  become  elon- 
gated, and  are  so  firmly  imbedded  in  the  surrounding  substance  that 
they  can  scarcely  be  dislodged.  The  blastema  gradually  acquires  a 
more  and  more  distinct  fibrous  appearance,  and  at  last  exhibits  a 
regular  filamentous  structure;  the  nuclei  themselves  undergoing 
little  change  during  this  time,  but  appearing  to  govern  the  direction 
of  the  fibrillation.  As  the  texture  goes  on  to  completion,  the  nuclei 
are  either  absorbed — which  seems  to  be  the  case  in  the  connecting 
tissue  formed  for  the  reparation  of  injuries,  as  well  as  in  the  normal 
development  of  tendons — or  tliey  undergo  a  further  development 
into  '  nuclear  fibres.'  This  is  effected  by  their  extension  at  both 
ends,  so  that  the  nuclei  thus  prolonged  meet  and  unite;  their  par- 
ticles taking  on  that  very  uniform  linear  arrangement  by  which  the 


cleated  cells.  6.  The  same,  be- 
coming pointed,  c.  The  same, 
become  fusiform,  the  nuclei 
being  still  apparent,  d.  The 
same,elongatedinto  fibres, the 
nuclei  having  disappeared. 


'  Paget's  "Lectures  on  the  Processes  of  Repair  and  Reproduction  after  Injuries," 
in  Medical  Gazette,  1849,  vol.  xliii.  p.  lOGD. 


THE   AREOLAR  TISSUE.  293 

fibres  of  this  tissue  (^.  e.  the  yellow  fibrous)  seem  to  be  characterized, 
and  sometimes  perhaps  undergoing  a  partial  or  complete  develop- 
ment into  cells.  The  rate  at  which  the  production  of  fibrous  tissue 
takes  place  in  the  manner  now  described  is  at  first  very  rapid,  well- 
marked  filaments  being  detectable  in  the  blastema  within  seven  or 
eight  days;  and  the  tenacity  of  the  bond  thus  formed  between  the 
two  ends  of  a  divided  tendon  is  such  that  in  one  of  Mr.  Paget's 
experiments,  within  ten  days  after  the  operation,  the  reunited  tendo- 
Achillis  of  a  rabbit  (the  new  tissue  being  a  cord  of  not  more  than 
two  lines  in  its  chief  diameter),  supported  a  weight  of  above  fifty 
pounds.  The  subsequent  changes  take  place  more  slowly ;  but  the 
reparation  of  divided  tendons  has  been  found  to  be  so  complete 
within  five  months  after  the  operation,  that  no  trace  of  the  sections 
could  be  discovered  even  by  microscopic  examination."^  It  is,  how- 
ever, to  be  remembered  that  non-infiamraatory  exudations  alone  can 
become  organized  in  this  way ;  they  passing  at  once  into  tissues, 
while  the  inflammatory  require  an  intermediate  process  of  cell-life 
to  accomplish  the  same  result  (p.  186). 

Regeneration  of  Areolar  Tissue. 

Areolar  tissue  is  very  perfectly  regenerated  if  removed;  but  the 
most  completely  so  in  situations  where  it  is  most  condensed,  or  ap- 
proaches more  nearly  to  mere  white  fibrous  tissue. 

Indeed,  it  is  an  imperfectly-developed  areolar  tissue,  rather  than 
the  original  one,  which  repairs  losses  of  substance  in  most  parts  and 
organs,  as  the  skin,  tendons,  and  even  the  parenchyma  of  organs — 
as  when  parts  of  the  liver  or  brain,  &c.,  are  removed  by  suppura- 
tion or  by  injury. 

Pathological  States  and  New  Formations  of  Areolar  Tissue. 
Here  we  have  to  distinguish  the  pathological  conditions — 

I.  Of  the  fibrous  framework  of  this  tissue. 
II.  Of  the  areolae  and  their  contents. 

I.  The  fibrous  framework  is  liable  to  atrophy,  in  which  the  blood- 
vessels collapse,  together  with  the  framework  in  which  they  are  dis- 
tributed. It  is  quite  probable  that  the  hypertrophy^  so  called,  of  the 
areolar  tissue  is  a  new  formation  of  the  same. 

II.  But  the  most  important  changes  occur  in  the  contents  of  the 
areolaa. 

'  Paget,  "Lectures,"  &:c.,  ut  supra,  p.  1070-71. 


294  THE   TISSUES. 

1.  An  increase  of  the  natural  serous  fluid  of  tlie  areolae  consti- 
tutes cedemaoT  swelling;  and  if  of  considerable  extent,  and  occurring 
in  tbe  subcutaneous  areolar  tissue,  it  constitutes  anasarca  or  dropsy, 
and  which  usually  occurs  in  the  lower  limbs  first,  for  the  reason 
specified  at  the  end  of  the  next  sentence.  In  dropsy,  moreover,  the 
tissue  yields  to  pressure,  or  "pits,"  since  the  fluid  is  forced  from  one 
areola  to  another;  and  it  also  passes  from  one  part  to  another  under 
the  influence  of  gravity. 

2.  In  case  of  inflammation  in  the  areolar  tissue  (areolitis),  the 
areolae  become  filled  with  an  exudation  instead  of  the  natural  trans- 
udation, and  which  may  become  subsequently  organized  (p.  187). 
If  so,  the  areolar  tissue  presents  an  indurated  feeling,  since  the 
areolae  are  filled  by  a  solid  substance ;  and  the  skin  becomes  quite 
immovable  over  the  indurated  portion.^ 

3.  If  the  exudation  filling  the  areolar  tissue  degenerates  into  pus, 
it  will  be  evacuated  by  ulceration,  if  it  is  not  so  artificially. 

4.  A  sudden  diminution  of  the  fluid  in  the  areolre  sometimes  oc- 
curs, as  in  Asiatic  cholera  and  other  diseases  attended  by  profuse 
liquid  alvine  discharges.  Here  the  fluid  is  absorbed  into  the  blood 
directly,  to  compensate  the  loss  from  this  fluid  by  the  transudation 
into  the  alimentary  canal  from  its  vessels.  The  immediate  eflect  is 
a  rapidly-induced  shrivelled  appearance  of  the  skin;  and  which  is 
more  apparent  in  infants,  while  it  is  also  soonest  removed  in  them 
after  the  discharges  cease. 

5.  Extravasated  blood  may  accumulate  in  the  areolee,  and  gravitate 
from  one  to  another,  as  is  seen  in  case  of  eccliymosis  under  the  skin. 
The  blood  is  removed  by  absorption,  or,  undergoing  a  change,  is 
discharged  by  the  ulcerative  process. 

6.  The  normal  fluid  in  the  areolae  may  be  replaced  by  air,  consti- 
tuting a  pneum^atosis  or  emphysema.  This  may  result  from  decom- 
position in  the  tissue,  but  more  frequently  from  the  air  being  forced 
into  the  areolae  from  without.  In  the  latter  case  it  may  be  soon 
reabsorbed  without  producing  injurious  consequences  (p.  286). 

7.  Fat-cells  may  fill  the  areola3  where  they  do  not  usually  exist, 
or  may  greatly  increase  where  ordinarily  found.  This  state  is,  how- 
ever, rather  a  hypertrophy  of  the  adipose  tissue,  as  will  be  seen.  It, 
however,  interferes  with  the  elasticity  of  tlie  areolar  tissue,  and  thus 
with  the  mobility  of  parts  and  organs;  and  so  far  produces  a  patho- 
logical condition  of  the  tissue  under  consideration. 

8.  In  case  of  atrophy  of  this  tissue,  the  areolas  are  filled  with  plates 
of  cholesterine,  pigment-cells,  and  often  also  the  carbonate  and  phos- 
phate of  lime. 

9.  The  subcutaneous  areolar  tissue  is  the  seat  of  numerous  patho- 
logical changes,  especially  sarcomatous  and  lipomatous  tumors.  The 
surgeon  must  also  bear  in  mind  the  changes  in  thickness  it  under- 

'  All  areolitis  sometimes  occurs  in  the  superficial  fascia  of  new-born  children, 
and  is  sometimes  termed  the  "skin-bound"  condition. 


V  ADIPOSE   TISSUE.  295 

goes — as  "has  been  stated  (p.  291) — in  case  of  ligation  of  the  large 
arteries,  since  they  lie  under  the  deep  fascia,  which  does  not  vary  in 
thickness,  and  require  a  division  of  the  superficial  fascia  to  arrive 
at  the  latter. 

10.  Reparative  new  formations  of  areolar  tissue  have  already  been 
described  (p.  292).  Pathological  new  formations  are  not  infrequent; 
often  constituting,  as  they  do,  the  stroma  of  cancerous  growths,  in 
the  areolce  of  which  the  cancer-cells  are  deposited.  It  is,  however, 
often  very  difficult  to  decide,  in  particular  instances,  whether  a  pa- 
thological new  formation  consists  mainly  of  the  white  fibrous  or  of 
the  areolar  tissue,  on  account  of  its  imperfectly-developed  state;  and 
some  of  the  formations  mentioned  on  page  283  would  by  some  ob- 
servers be  regarded  as  of  the  areolar,  rather  than  of  mere  collagenous 
tissue. 


CHAPTER    Y 


ADIPOSE   TISSUE. 


Adipose  tissue  and  fat,  are  terms  often  used  to  denote  the  same 
thing.  But  we  have  seen  that  human  fat  is  a  fluid — a  compound 
of  oleine,  margarine  and  stearine ;  the  first  holding  the  other  two 
in  solution  (p.  76, 1).  It  is  also  found  constituting  in  part. the  gran- 
ules in  almost  all  kinds  of  cells  (epithelial,  &c.),  and  in  the  form  of 
minute  drops  (fat  globules),  in  the  interstices  of  many  tissues  (p. 
73). 

But  in  adipose  tissue,  the  fat  is  contained  in,  and  completely  fills 
the  adipose  cells ;  and  the  tissue  consists  of  the  two  following  ele- 
ments : — 

I.  The  adipose,  or  fat-cells. 

II.  A  matrix  of  areolar  tissue  diffused  among  the  cells, 
and  holding  them  together — the  intercellular  areolar 
tissue. 

I.  The  adipose  cells  (Fig.  185),  are  peculiar  in  several  respects. 
1st.  They  contain  no  granules;  but  only  the  clear  fluid  before  men- 
tioned. 2d.  "When  fully  developed,  they  have  no  apparent  nucleus 
or  nucleolus ;  though  Kolliker  alwaj^s  finds  a  nucleus  when  they 
are  but  partially  filled.     3d.  The  cell-wall  is  apparently  of  simple 


296 


THE   TISSUES. 


membrane,  but  very  thick  comparatively — even  txjV^  of  ^^  inch,' 
•itb.  The  fat-cell  is  also  larger  than  other  cells,  being  from  yt^s  to 
j^^  of  an  inch  {Kollilcer\  and  averaging  g^o-  of  an  inch  in  diameter. 
They  are  smallest  in  young  animals.  Those,  however,  of  the  same 
}nass  differ  in  size.     They  present  no  peculiarity  in  respect  to  form; 


Fig.  185. 


Fig.  ISo.  Normal  f;it-cells  from  the  breast,  a.  Without  reagents.  6.  After  being  treated  withetlicr, 
whereby  the  fat  i.s  exhausted  and  the  folded  delicate  membrane  remains. — Magnified  350  diameters. 
(Kaiiker.) 

Fig.  186.  Fat-cells  assuming  the  polyhedral  form  from  pressure  against  one  another ;  from  the  omen- 
tum.    (Magnified  about  300  diameters.) 

being  globular  originally  and  in  young  animals,  and  polygonal 
when  pressed  together  in  a  mass  in  the  adult.  (Fig.  186.) 

In  color,  adipose  cells  are  usually  of  a  yellowish  shade;  but 
lighter  in  young  than  adult  animals.  Hence  adipose  tissue  is  usu- 
ally of  this  color. 

The  contents  of  the  fat-cells  become  solid  at  the  temperature  of 
63°  (Fahr.)  and  lower,  since  the  oleine  congeals  at  this  temperature. 
After  death,  therefore,  human  fat  is  solid. 

II.  The  connective  tissue  between  the  fat-cells  usually  presents 
nothing  peculiar,  it  being  mere  areolar  tissue.  It  is,  however, 
sometimes  merely  a  connective  substance  or  plasma.  {Kblliker)  It 
has  already  been  shown  that  fat-cells  often  fill,  partially  or  entirely, 
the  areolae  of  areolar  tissue,  as  of  the  superficial  fascia ;  though  a 
small  amount  of  areolar  fluid  still  exists  between  the  cells,  except 
where  thc}^  are  in  perfect  contact.  But  in  case  of  adipose  tissue, 
the  cells  arc  aggregated  in  larger  masses,  and  the  connective  areolar 
tissue  is  comparatively  slight  in  amount.     These  masses  take  the 


'  Toild  and  Bowiuan  think  each  fat-cell  has  its  own  envelop  of  areolar  tissue, 
and  its  distinct  vessels.  This  is,  however,  certainly  not  the  case  with  all  of  them, 
though  it  is  with  some. 


ADIPOSE   TISSUE. 


297 


Fig.  187. 


form  of  lobes  or  lobules,  wliich  are  also  bound  together  by  still 
larger  fasciculi  of  areolar  tissue.  The  relations  of  the  fat-cells  and 
the  intercellular  connective  tissue  are  shown 
by  Fig.  187. 

Vessels  of  Adl'pose  Tissue. — Each  f;it-cell  is 
surrounded  by  a  loop  or  loops  of  capillary 
bloodvessels ;  all  the  capillaries  of  a  single 
terminal  artery  looping  around  the  cells  of 
a  single  lobule.  (Fig.  188.)  Hassall  com- 
pares such  a  lobule  of  cells  to  a  bunch  of 
grapes.  The  vessels  of  the  lobule  do  not, 
however,  apparently  grow  from  the  cells  like 
the  stems  of  grapes,  though  there  is  a  gene- 
ral analogy.  No  nerves  or  lymphatics  be- 
long to  the  adipose  tissue,  though  both  may 
be  found  traversing  it  on  their  way  to  other 
tissues. 

Peculiarities. — Sometimes  a  minute  star- shaped  body  may  be  seen 
in  a  fat-cell  in  the  human  subject.     (Fig.  189.)     This  is  generally 


Adipose  tissue,  a,  a.  Fat-cells. 
b,  b.  Fibres  of  intercellular  areo- 
lar tissue. 


Fig.  188. 


Bloodvessels  of  fat.  1.  Minute  flattened  fat-lobule  in  which  the  vessels  only  are  represented.  3. 
The  terminal  artory.  4.  The  primitive  vein.  5.  The  fat-cells  of  one  border  of  the  globule  separately 
represented.  (Magnified  100  diameters.)  2.  Plan  of  the  arrangement  of  the  capillaries  on  the  exte- 
rior of  the  cells,  more  highly  magnified. 

said  to  consist  of  the  margarin  in  a  crystalline  form.  Kolliker, 
however,  regards  it  as  margaric  acid.  This  appearance  is  more 
common  in  the  aged. 


298 


THE   TISSUES. 


Fat-cells  with  crystals  of 
raargaric  acid.  a.  Cell  with 
a  star  of  crystalline  needles, 
as  they  may  be  found  not  un- 
commonly in  normal  fat.  b. 
Cell  quite  filled  with  crystals, 
from  the  white  fat-lobules  of 
an  emaciated  subject. — Mag- 
nified 350  diameters.  {KiJlli- 
ker.) 


Fig- 189.  In  the  emaciated  subject  scarcely  any  nor- 

mal fat-cells  are  met  with ;  but  this  topic  will 
be  resumed  in  the  last  subdivision  of  this 
<!hapter. 

Peculiarities  in  the  Lower  Animals. 

Fat  cells  do  not  exist  in  the  invertebrata, 
though  fat-globules  do  (p.  73),  and  often  in 
great  abundance.  There  is,  therefore,  in 
them  no  true  adipose  tissue.  The  larvas  of 
insects  contain  a  large  amount  of  fat-glo- 
bules. 

The  fat-cells  of  the  pig  are  generally  some- 
what kidney-shaped.  In  birds,  they  are 
smaller  than  in  man,  and  often  contain  a 
bright  colored  fluid;  e.g.  the  bright  colors 
about  the  beak,  and  of  the  legs  in  some  spe- 
cies, are  said  to  depend  on  layers  of  cells 
beneath  the  skin  containing  colored  fat.  The  bright  colors  of  cer- 
tain crustaceans  and  reptiles,  are  also  due  to  a  similar  cause,  when 
not  dependent  upon  pigment-cells,  Wagner  believes  that  the  color 
of  the  iris  in  birds  is  also  due  to  a  deposit  of  fat. 

The  fat  of  different  animals  presents  four  varieties,  so  far  as  its 
density  after  death  is  concerned ;  viz.,  oil,  lard,  tallow,  and  sperma- 
ceti— the  first  containing  the  most  oleine,  and  the  last  the  most 
stearine.  The  fat  of  the  bear  does  not  congeal  at  ordinary  tempe- 
ratures, ^.  e.  it  remains  an  oil;  and  hence  its  value  to  perfumers. 
Lard  is  obtained  from  the  hog ;  tallow  from  the  ox,  sheep,  &c., 
and  spermaceti  from  cavities  in  the  cranium  of  the  whale.  Human 
fat  is  intermediate  in  density  between  lard  and  tallow.  The  fat 
upon  the  omentum  of  the  sheep  is  called  suet. 

Chemical  Composition  of  Adipose  7'issue. 
This  includes,  (1)  the  composition  of  the  fluid  fat  itself;  (2)  that 
of  the  walls  of  the  fat-cells;  and  (3)  of  the  intercellular  areolar 
tissue, 

1.  If  adipose  tissue  be  exposed  to  a  high  temperature  thcf.it-cells 
burst,  and  the  fat  escapes;  the  cell-walls  and  the  areolar  tissue  form- 
ing a  solid  residue.  It  has  already  been  shown  that  the  fat  consists 
of  oleine,  stearine,  and  margarine;  and  their  composition  has  been 
specified  on  page  76. 

2.  The  composition  of  the  cell-wall  is  not  preci.sely  known ;  but 
there  is  no  room  to  doubt  that  it  is  an  albuminous  compound. 


ADIPOSE   TISSUE.  299 

3.  The  intercellular  areolar  tissue  has  the  same  composition  as 
areolar  tissue  in  other  situations  (p.  287). 

It  should  be  added  that  a  small  amount  of  serous  fluid  bathes  the 
fat-cells — the  intercellular  jlxdd;  and  which  (iocs  not  differ  in  com- 
position from  that  in  the  areohe  of  the  areolar  tissue. 

Distribution  of  Adipose  Tissue  in  Man. 

This  tissue  is  very  generally  diffused  throughout  the  human 
organism,  and  in  the  adult  usually  constitutes  about  ^V  part  of  the 
weight  of  the  body.  In  women  and  children,  however,  it  averages 
somewhat  more  than  this  proportion. 

It  has  been  seen  (p.  290),  that  fat-cells  exist  in  the  areohe  of  the 
superficial  fascia,  in  most  situations.  This  is,  however,  not  much 
developed  in  the  foetus  till  the  sixth  month,  and  hence  a  foetus  born 
at  or  before  this  period,  has  a  peculiar  shrivelled  look ;  while  at  the 
full  term  it  is  plump  and  well-rounded.  Some  of  the  areolar  fluid 
also  remains  between  the  fat-cells  in  the  superficial  fascia. 

In  the  following  parts,  fat  is  most  abundant  in  the  adult;  upon 
the  soles  of  the  feet  and  the  palms  of  the  hands ;  npon  the  pubes 
and  the  nates;  around  the  mammary  gland  of  the  female;  upon  the 
great  omentum,  and  beneath  the  skin  of  the  abdomen.^  It  is  also 
accumulated  between  the  inner  layer  of  the  pericardium  and  the 
substance  of  the  heart;  around  the  origin  of  the  large  vessels;  in 
the  orbital  cavity;  in  the  spinal  canal,  outside  of  the  theca  verte- 
bralis,  and  in  the  medullary  cavities  of  the  bones.  In  cases  of  the 
extremest  emaciation,  the  fat  does  not  entirely  disappear  in  the 
parts  mentioned  in  the  preceding  sentence.  Fat  is  also  deposited 
around  joints,  and  in  many  fossae.  The  fat  in  bones  is  called  mar- 
row, and  differs  from  ordinary  adipose  tissue  only  inasmuch  as  its 
cells  contain  somewhat  more  oleine  [Lehmann) ;  are  more  globular, 
from  not  being  exposed  to  pressure ;  and  in  containing  but  a  slight 
admixture  of  areolar  tissue. 

On  the  other  hand,  since  the  contents  of  the  fat-cells  are  liable  to 
undergo  sudden  variations  in  quantity,  there  are  certain  parts  in 
which  no  adipose  tissue  is  ever  found.  These  are  the  ej^elids,  the 
ears  (except  the  lobule),  the  lungs,  the  penis  and  scrotum,  the  cli- 
toris, the  nymphas,  between  the  rectum  and  bladder  in  the  male, 
and  between  the  rectum  and  vagina  in  the  female ;  on  the  brain  and 

'  In  those  situations  where  the  areolre  of  the  subcutaneous  areoLiv  tissue  inclose 
fat-cells,  KoUiker  terms  it  the  paniiiculus  adiposus. 


300  THE   TISSUES. 

in  the  axilla;  and  hence  tliese  parts  (except  the  brain)  become 
highly  oedematous  (p.  294,  1)  from  inflammation,  contusions,  &c.;  as 
the  pans  whose  areola  are  filled  with  fat-cells  cannot.  Besides,  it 
does  not  exist  under  tke  epicranial  aponeurosis,  under  the  mucous 
membranes,^  in  the  corium  of  the  skin,  nor  between  overlapping 
muscles. 

The  fat  in  the  brain  and  nerves,  is  not  in  the  form  of  adipose 
tissue — not  in  fat-cells;  but  enters  into  the  chemical  composition  of 
the  tissues  themselves. 

Fat-cells  are  never  entirely  absent  in  the  heart,  in  the  orbit,  and 
between  the  muscles  of  the  face. 

Peculiarities  of  Distrihuiioyi  of  Fat. 

The  adipose  tissue  under  the  skin  of  the  abdomen  sometimes 
accumulates  to  a  great  amount,  in  one  instance  forming  a  layer  14 
inches  thick !  This  increase  is  most  likely  to  occur  in  men  at  the 
age  of  about  forty  years.  Occurring  also  in  women  at  this  period, 
or  somewhat  earlier,  and  most  frequently  in  those  who  have  never 
had  children,  the  consequent  enlargement  has  sometimes  been  mis- 
taken for  a  time  for  pregnancy. 

It  has  been  observed  that  Hottentot  women  manifest  a  peculiar 
tendency  to  the  accumulation  of  fat  upon  the  nates;  which  does 
not,  however,  appear  till  after  the  birth  of  a  child.  This  is  by  them 
considered  an  important  element  of  female  beauty.  In  all  male 
animals,  on  the  other  hand,  a  tendency  to  accumulate  fat  is  pro- 
duced by  castration.  It  often  also  accumulates  in  women  when 
they  cease  to  conceive,  and  in  those  who  are  barren. 

Certain  individuals  are  remarkable  for  the  accumulation  of  fat 
upon  the  body  generally,  while  others  are  as  remarkable  for  a  desti- 
tution of  it.  A  Greek  writer  tells  of  a  person  who  was  obliged  to 
attach  iron  to  his  sandals,  lest  he  be  blown  away  when  he  went 
abroad.  On  the  other  hand,  Daniel  Lambert,  the  Lancastershire 
giant,  weighed  739  pounds;  the  circumference  of  his  body  being 
9  feet  4  inches,  and  of  his  leg,  3  feet  1  inch.  His  coffin  was  6 
feet  4  inches  long,  4  feet  4  inches  wide,  and  2  feet  4  inches  deep. 
The  author  saw  a  young  woman  in  Paris,  18  years  of  age,  who 
weighed  over  500  pounds.  Paolo  Moccia  was  so  fat  as  to  weigh  30 
pounds  less  than  his  bulk  of  water,  and  consequently  he  could  not 

'  An  exception  is  found  in  tlie  soft  palate,  where  there  is  an  abundance  of  yellow 
fat,  often  seen  through  the  nn'iuhrano  in  the  case  of  anemic  subjects. 


ADIPOSE   TISSUK.  301 

sink  in  water.  And  a  Spanish  general,  wlio  was  enormously  cor- 
pulent, is  said  to  have  removed  the  fat  so  rapidly  by  drinking  large 
quantities  of  vinegar,  that  he  could  wrap  the  loose  skin  around  him 
like  a  cloak.  * 

Such  extreme  degrees  of  obesity  must,  however,  be  regarded 
rather  as  a  pathological  condition,  and  which  is  incompatible  with 
a  long  life.  So  great  a  weight  of  fat  encumbers  the  heart  especially, 
and  hence  the  pulse  becomes  feeble,  and  loss  of  blood  is  not  well 
tolerated.  In  view  of  the  ultimate  consequences,  therefore,  this 
condition  (called  polysarcia)  often  requires  the  adoption  of  means 
to  diminish  the  amount  of  fat.  The  author  is  cognizant  of  an  in- 
stance in  which  this  object  was  very  promptly  secured  by  the  use 
of  nitric  acid.  But  it  has  been  shown  by  Dr.  T.  K,  Chambers,  in 
his  "Lectures  on  Obesity,"*  that  the  most  reliable  remedy  in  such 
cases  is  the  liquor  potassae.  It  is  possible  that  the  fat  is  reabsorbed 
into  the  blood  from  the  fat  cells,  to  combine  with  the  potassa  and 
form  a  soap  or  emulsion;  after  which  it  is  burned  up  by  combina- 
tion with  oxygen,  as  a  calorific  element.  For  such  an  absorption 
into  the  blood,  doubtless  occurs  from  the  fat-cells  in  cases  of  emacia- 
tion; and  Henle  has  seen  the  blood  so  laden  with  fat  after  a  profuse 
hemorrhage,  that  it  formed  a  distinct  pellicle  on  its  surface. 

A  superabundance  of  adipose  tissue,  or  a  privation  of  it,  has 
alike,  in  all  ages,  been  regarded  as  a  legitimate  subject  of  derision. 
Sir  John  Falstaff  is  the  impersonation  of  the  class  included  in  the 
first  category,  except  perhaps  in  respect  to  his  activity;  who  repre- 
sents himself  as  being  "a  man  of  continual  dissolution  and  thaw," 
and  who  had  "a  kind  of  alacrity  in  sihking."^  The  dramatist  has, 
however,  committed  a  physiological  mistake  in  the  last  expression, 
as  has  already  been  shown.  He  has,  however,  in  another  passage, 
recognized  the  effect,  in  diminishing  the  deposit  of  fat,  of  intense 
and  continued  intellectual  effort  and  anxiety,  and  consequent  loss 
of  sleep : — 

"  Let  me  have  men  about  me  that  are  fat ; 
Sleek-headed  men,  and  such  as  sleei)  o'  nights. 
Yond'  Cassius  has  a  lean  and  hungry  look  : 
He  thinks  too  much:  such  men  are  dangerous." 

Julius  Ccesar,  act  i.  sc.  2. 

'  London  Lancet,  for  1850,  vol.  ii.  p.  443. 

^  "You  may  knovr  by  my  size  that  I  have  a  kind  of  alacrity  in  sinking." 

"Think  of  that;  a  man  of  my  kidney — think  of  that;  that  am  as  subject  to 

heat  as  butter;  a  man  of  continual  dissolution  and  thaw.     It  was  a  miracle  to 

escape  suffocation." — Merry  Wives  of  Windsor,  act  iii.  sc.  5. 


302  THE   TISSUES. 

It  has  been  sometimes  remarked  that  fat  men  can  endure  loss  of 
sleep  better  than  the  lean.  So  far  as  this  is  the  fact — and  it  is  be- 
lieved to  be  generally  true — the  author  is  inclined  to  associate  it 
with  more  active  powers  of  nutrition,  which  secure  the  deposit  of 
fat  in  spite  of  the  privation  of  sleep.  The  dyspeptic,  on  the  other 
hand,  requires  more  sleep ;  though  with  it,  even,  he  remains  lean. 
There  is,  however,  in  some,  a  constitutional  tendency  to  deposit  fat; 
and  who,  though  they  become  confirmed  dyspeptics,  still  continue 
in  good  condition  in  this  respect.  Indeed,  there  are  also  national 
differences  in  this  respect.  Englishmen  are  more  prone  to  corpu- 
lence than  Americans;  a  result,  probably,  of  the  combined  influence 
of  a  freer  use  of  fermented  liquors,  and  of  a  damper  climate  in 
England ;  for  the  former  contain  elements  favorable  to  the  depo- 
sition of  fat,  and  the  latter  induces  a  less  active  condition  of  the 
skin.  The  Bedouin  Arabs  are,  on  the  other  hand,  remarkable  for 
their  leanness ;  for  which  their  simple  and  spare  diet  and  the  dry 
atmosphere  in  which  they  live,  together  with  their  active  habits, 
must  mainly  account.^ 

Girciim stances  modifying  the  Deposit  of  Fat. 

A  constitutional  tendency  to  deposit  fat  has  been  alluded  to;  but 
several  circumstances  also  exert  a  powerful  influence  in  this  respect. 
The  most  important  are : — 

1.  The  kind  of  diet. 

2.  The  amount  of  exercise. 

3.  The  state  of  the  function  of  respiration. 

1.  The  non-nitrogenized  elements  of  our  food — starch,  sugar, 
gum,  dextrine,  and  fat — tend  specially  to  the  development  of  fat. 
So  also  do  distilled  and  fermented  liquors. 

'  Not  a  few  epitaphs  have  been  suggested  by  the  present  subject,  and  two  may 
be  forgiven  here.  The  first  commemorates  the  burial-place  of  a  remarkably  cor- 
pulent deacon : — 

"Take  heed,  gentle  traveller,  anil  do  not  tread  hard, 
For  hero  lies  Deacon  Stafford  in  all  this  churchyard." 

The  other  epitomizes  the  life  and' the  death  of  an  honest  tallow-chandler,  who, 
becoming  very  wealthy  from  success  in  business,  retired  to  the  country,  and  there 
became  so  obese  froni  inaction,  that  he  died  in  consequence : — 

"rioro  lies  in  earth  an  honest  fcllovr, 
Who  dUd  \>yfat,  but  lived  by  taUow." 


ADIPOSE   TISSUE  .  303 

2.  A  sedentary  or  a  sluggish  life  also  favors  the  deposit  of  fat. 
Even  carnivorous  animals,  though  always  lean  in  their  natural 
state,  become  fat  when  closely  caged,  and  fed  on  a  mixed  diet. 

3.  Breathing  an  atmosphere  imperfectly  supplied  with  oxygen, 
is  a  third  cause  of  fatty  deposit.  To  this  we  may  also,  doubtless, 
add  privation  of  solar  light,  and  a  damp  atmosphere. 

4.  On  the  contrary,  a  diet  more  exclusively  nitrogenized  (albu- 
men, musculine,  &;c.,  as  in  eggs  and  lean  meat),  abstinence  from 
distilled  and  fermented  liquors,  and  habitual  active  exercise  in  the 
open  air,  tend  to  prevent  an  accumulation  of  fat,  or  to  remove  it  if 
already  existing. 

Moreover,  emaciation  may  be  induced  by  a  prolonged  discharge 
of  any  fluid  containing  a  considerable  proportion  of  fat.  Hence 
profuse  suppuration  or  hemorrhage,  or  excessive  sexual  indulgence, 
produces  leanness,  since  pus,  blood,  and  semen  are  rich  in  fat  (p.  74). 

While  the  fat  in  the  fat-cells  is  the  most  rapidly  formed,  it  is  also 
the  most  rapidly  resorbed,  of  all  the  immediate  principles  of  the 
human  body.  It  is  its  sudden  diminution  around  the  eyeball  which 
gives  the  sunken  appearance  to  the  eye,  even  a  few  hours  after  the 
invasion  of  certain  acute  diseases.  This  change  is  most  rapid  in 
children ;  and  they  also  most  rapidly  refill  the  fat-cells  when  con- 
valescence is  established. 

Distribution  of  Advpose  Tissue  in  the  Lower  Animals. 

Carnivorous  animals  are  naturally  lean,  since  they  are  necessarily 
active,  and  live  principally  on  the  nitrogenized  immediate  princi- 
ples contained  in  the  flesh  of  other  animals. 

Herbivorous  animals,  on  the  other  hand,  manifest  a  tendency  to 
accumulate  fat.  They  are  less  active,  and  consume  large  propor- 
tions of  starch  and  gum.  By  way  of  exception,  however,  the  rabbit 
is  said  to  be  almost  entirely  destitute  of  fat,  and  in  some  instances 
none  at  all  can  be  discovered.  There  is  a  species  of  sheep  in  Asia 
which  accumulates  a  mass  of  fat  which  is  situated  in  the  place  of  a 
tail;  which  swings  to  and  fro  as  the  animal  walks,  and  sometimes 
weighs  even  40  pounds.  Fat  is,  however,  usually  most  abundant,  in 
ruminating  animals,  about  the  kidneys.  In  others  it  abounds  in  the 
mesentery  and  the  omentum;  and  in  others  still,  in  the  areolar  tissue 
under  the  skin.  The  latter,  in  the  seal  and  the  whale,  is  called  "blub- 
ber ;"  and  from  a  single  whale  120  tons  are  sometimes  obtained — 
the  deposit  being  from  4  to  20  inches  thick.  Spermaceti  is,  however, 
found  in  the  sperm-whale,  in  two  cavities  of  the  cranium;  while  the 
cells  of  the  adipose  tissue  also  contain  crystals  of  it.  (Fig.  190.)    The 


304 


THE   TISSUES. 


Fig.  190. 


cranial  cavities  sometimes  yield  20  tons.     Hibernating  animals  lay 

up  a  large  store  of  fat  as  the  winter  sea- 
son approaches,  and  which  is  consumed 
to  maintain  the  animal  heat  during  their 
dormant  winter  state.  Hence  they  are 
found  to  be  again  comparativelj''  ema- 
ciated on  emerging  in  the  spring  from 
their  winter  quarters.  In  the  camel,  the 
"luimps"  are  masses  of  adipose  tissue, 
and  are  absorbed  to  sustain  the  animal, 
if  suffering  from  privation  of  food. 

In  hirds,  fat  is  found  deposited  prin- 
cipally between  the  abdominal  muscles 
and  the  peritoneum.  In  aquatic  birds  it 
is  deposited  in  the  bones  of  the  legs,  and 
the  last  bone  of  the  wings  and  of  the 
tail. 

In  rejotiles,  fat  is  found  chiefly  in  the  abdomen. 
In  fishes,  fat-cells  are  distributed  throughout  the  body  generally, 
except  in  the  cod,  the  haddock,  and  the  whiting.     ]n  all  these,  fat 
is  found  only  in  the  liver.  (See  p.  79.) 

It  has  been  seen  that  fat-cells  do  not  exist  in  the  invertebrate  ani- 
mals. Fat,  however,  abounds,  in  the  form  of  globules,  in  the  mol- 
lusca  (oyster,  &;c.);  and  in  the  insect,  both  in  the  pupa  and  in  the 
perfect  (or  imago)  state. 

The  trying  out  the  fat  of  the  lower  animals  consists  in  heating  the 
adipose  tissue  till  the  fat-cells  burst  and  set  free  their  contents.  The 
scrcqis  are  the  remaining  areolar  tissue  and  vessels. 


Adipose  tissue  of  sperm-whale,  a, 
A.  Cells  containing  crystals  of  sperma- 
ceti. B,  B.  Crystals  of  spermaceti  on 
the  outside  of  cells.  (Queckett.) 


Uses  of  Fat  as  a  Tissue. 
Adipose  tissue  fulfils  merely  chemico-physical  oflices  in  the  or- 
ganism. 

1.  It  renders  the  skin  soft  and  flexible.  Eeference  is  here  made 
to  the  fat  in  the  superficial  fascia,  or  subcutaneous  areolar  tissue. 

2.  It  gives  roundness  and  symmetry,  and  hence  grace  and  beauty, 
to  the  body.     Hence  it  is  more  abundant  in  the  female. 

3.  It  is  a  protection  against  pressure ;  as  on  the  nates,  mons  ve- 
neris, lacteal  glands,  &c. 

4.  It  facilitates  motion  ;  as  package  between  muscles,  as  depo- 
sited under  the  skin,  around  the  eyeballs  and  the  heart,  and  in  the 
omentum. 

5.  It  is  a  protection  against  cold,  being  a  bad  conductor  of  heat. 
Thus  it  is  found  under  the  skin,  around  the  heart  and  large  vessels, 
the  lacteal  glands,  in  the  great  omentum,  &c. 


ADIPOSE  TISSUE.  305 

6.  Fat,  by  its  low  specific  gravity,  renders  the  human  body  lighter 
than  its  bulk  of  water  in  proportion  to  its  amount,  Ilence  it  is  an 
aid  in  swimming. 

7.  Lastly,  the  fat  in  the  adipose  tissue  may  become  useful  as  nu- 
tritive material  in  cases  of  emergency;  the  fat  being  reabsorbed 
into  the. blood,  and  then  becoming  "fuel  for  respiration"  (p.  77,  2). 

Fluid  fat  alone  is,  however,  merely  calorific,  and  will  not  long 
sustain  an  animal  (p.  76,  3).  But  adipose  tissue,  taken  as  food  into 
the  stomach,  will  nourish  for  a  long  period,  as  demonstrated  by 
Magendie ;  since  it  also  contains  albuminous  elements  in  its  cell- 
walls,  and  osteine  in  its  areolar  tissue.  The  fact  that  all  cells  need 
fat  for  their  development,  since  all  nucleoli  consist  of  fat  [Hune- 
feld),  has  already  been  specified  (p.  78, 5).  Hence  its  necessity  in  the 
blood ;  whence  it  is  also  derived  for  the  formation  of  bile  and  other 
secretions  (p.  77,  2).  The  use  of  fat  in  the  food,  as  an  aid  to  digestion, 
has  also  been  specified  (p.  78,  5) ;  and  Lehmann  suggests  that  the 
pancreatic  fluid  owes  its  power  in  this  respect  to  the  fat  it  contains. 
But  in  all  these  fluids  we  find  mere  fat-globules,  and  not  fat-cells. 

Development  of  Adipose  Tissue. 

The  adipose  or  fat-cell  manifests  no  peculiarity  in  its  develop- 
ment.    At  first  small  and  nucleated,  it  subsequentl}^  increases  in 
size,  and  its  nucleus  disappears.     Kcilliker  never 
fails  to  find  the  nuclei,  however,  when  the  cells  are  Fig-  191- 

only  partially  filled  with  fat;    and  it  must  there-  >J 

fore  be  persistent,  (Fig.  191,)  y^^^^^. 

The  first  lobules  of  fat  appear  in  the  fourth         /m^         'm, 
month  of  intra-uterine  life,  in  the  palms  of  the         m  .a| 

hands  and  the  soles  of  the  feet.     The  subcuta-  ^^jatfit^^ 

neous  adipose  tissue  is  rapidly  developed  from 

'-  .  A  fat-cell  to  show  the 

the  seventh  month  to  birth.     Hence  the  foetus  at    nucleus;  from  Schwann, 
five  or  six  months  has  a  wrinkled  condition  of    *^;  ^'^^^■'^'^^^-     ^-  ^''^■ 

cleus. 

the  skin  generally. 

Is  the  fat  in  the  organism  formed  from  fat  alone  in  the  food  ? 
There  is  reason  to  believe  not  only  that  starch,  sugar,  &c.,  may  be 
converted  into  fat  in  the  organism,  to  a  very  slight  extent,  but  that 
even  from  albumen  also  fat  may  be  formed  in  small  quantity  in  the 
alimentary  canal  (p.  74).  Still,  neither  of  these  two  points  can  be 
regarded  as  established,  (Lehmann.^) 

'  Physiological  Chemistry,  vol.  i,  pp,  230-32. 
20  \ 


306  THE   TISSUES. 

Growth  of  Adipose  Tissue. 

Hassall  maintains  that  the  fat-cells  of  each  individual  persist 
through  life ;  they  being  merely  larger  or  smaller,  or  more  or  less 
full,  in  the  varying  states  of  the  adipose  tissue.  In  cases  of  extreme 
corpulence,  however,  there  can  be  no  reasonable  doubt  of  their  in- 
crease in  number.  Hassall  finds  the  fat-cells  several  times  smaller 
in  infants  than  in  adults;  and  they  doubtless  increase  after  birth, 
as  do  the  cartilage-cells  (though  probably  more  slowly),  in  size 
rather  than  in  number. 

The  growth,  however,  appears  to  proceed  at  different  rates  in 
different  parts  of  the  body  after  birth,  and  also  in  the  same  part  in 
different  persons  of  the  same  age.  Harting  states  that  in  the  adult 
the  fat-cells  in  the  orbit  are  twice  as  large,  and  in  the  palm  three 
times  as  large,  as  at  birth. 

Regeneration. — It  is  doubtful  if  fat-cells  are  reproduced  after  a 
mass  of  the  adipose  tissue  is  removed ;  the  loss  being  repaired  by  a 
more  condensed  areolar  tissue,  such  as  usually  constitutes  the  sub- 
stance of  cicatrices. 

Pathological  States  and  New  Formations  of  the  Adipose  Tissue. 

I.  Atrophy  of  the  adipose  tissue  is  one  of  its  most  common  patho- 
logical conditions,  occurring  in  all  cases  of  emaciation,  and  in  ana- 
sarca. Here  either  the  cells  are  partially  collapsed,  or  their  contents 
become  changed.  Kcilliker  specifies  the  following  conditions  of  the 
contents  of  atrophied  fat-cells : — 

1.  The  cells  are  granular,  containing  numerous  small  fat-drops, 
forming  whitish-yellow  clustered  lobules. 

2.  Cells  containing  a  dark  globule  only  of  fat,  the  rest  of  their 
contents  being  removed. 

3.  Cells  containing  serum  alone,  the  fat  having  been  entirely  re- 
moved. 

The  last  two  varieties  occur  in  anasarca.  Kolliker  states  that^in 
this  disease  the  cells  also  assume  a  stellate  form  (with  from  three  to 
five  processes),  and  become  diminished  in  size.  Wedl,  however, 
suggests  that  these  are  young  cells  of  white  fibrous  tissue. 

When  the  fat  leaves  the  cells,  it  must  first  be  mixed  with  the 
intercellular  fluid,  and  then  real)sorbcd  by  the  lymphatics.  It  is 
the  accumulation  of  the  serous  fluid  in  the  areola3  of  the  areolar 
tissue  in  dropsy,  which  causes  the  fat  in  the  cells  to  disappear,  partly 
perhaps  by  exosmosis;  when  the  fat-cells  become  entirely  filled,  in 
turn,  with  the  serous  fluid. 


ADIPOSE   TISSUE. 


SO^ 


4.    Fat-cells    containing  F'g- 192. 

crystals  of  margaric  acid, 
with  a  drop  of  fat;  or  which 
are  entirely  filled  with  the 
former. 

The  varieties  just  men- 
tioned are  represented  by 
Fig.  192 ;  and  in  all  of  them 
the  nucleus  and  nucleolus 
become  very  distinct. 

5.    Wedl    adds    another 
variety,    in   which  The   fat 
is  subdivided  into  a  multi- 
tude of  globules,  often  group- 
ed around  a  lighter-colored 
space  (serum). — In  many  of 
these    cases    the    cell-mem- 
branes are  no  longer  visible, 
they  having  doubtless  been 
dissolved ;    and   no  vestige 
of  the  nucleus  can  be  per- 
ceived.    He  also  finds  that  the  cell-membrane  is  thickened  in  some 
cases  of  atrophy  of  the  cell-con- 
tents,   several    concentric    layers 
being  visible  on  its  inner  aspect. 
These  two  conditions  are  shown 
by  Fig.  193,  where  three  normal 
fat-cells   are  also   added,  for   the 
sake  of  comparison. 

Remarks. — Emaciation  occurs  in 
almost  all  chronic,-  and  in  many 
acute  diseases.  It  is  especially 
marked  before  death  by  tubercu- 
losis and  by  dropsy.  In  some  cases 
of  the  latter,  the  fat  of  the  adipose 
tissue  entirely  disappears,  except 
around  the  heart,  and  serum  takes 
its  place  in  the  adipose  cells,  as  has 
been  explained.  It  is,  however, 
a  singular  fact  that  even  phthisis 
■  generally  produces  little  or  no  ema- 
ciation (even  though  the  structure 
of  the  lungs  is  in  a  great  measure 
destroyed),  provided  the  liver  is  also 
at  the  same  time  diseased;  especially 
if  from  stearosis,  or  the  "nutmeg 
liver,"  as  it  is  called.     In  tubercu- 


Atrophied  fat-csUs  from  the  subcutaneous  areolar  tis  - 
sue  of  an  aged  aad  much-emaciatodperson.  a.  Fat-cell 
shrunken,  with  crumbling,  dark  brownish-yellow  con- 
tents ;  beneath  it  one  of  lighter  color,  with  crystals  ra- 
diating towards  the  border,  b.  An  atrophied  pigmented 
fat-cell  in  apposition  with  one  in  the  normal  condition. 

c.  Cells  filled  with  a  serous  fluid,  and  presenting  in  their 
contents  well-marked  circles  (fat-globules  in  suspension), 
and  delicate,  oval,  simple  or  double  granules  (nuclei). 

d.  Cells  containing  serum,  and  whose  walls  are  lami- 
nated.— Magnified  350  diameters.  {Wedl.) 


Fig.  193. 


Atrophied  adipose  tissue  from  the  capsn!-' 
of  a  gelatinous  sarcoma,  a,  a.  Rows  of  atro- 
phied fat-globules,  for  the  most  part  without 
any  cell-membrano.  b.  Groups  of  normal  fat- 
c-cUs  accompanying  tho  above,  c.  Enlarge- 
ments and  bifurcate  division  of  the  elastic 
fibres  running  among  the  rarefied  fat-cells. — 
Jlagnified  3:50  diameters.  (Wedl.) 


308 


THE   TISSUES. 


losis,  also,  the  saponified  fats  are  far  more  diminished  in  the  blood 
than  in  any  other  fluid.^  (p.  78.) 

II.  In  case  of  hy'pertroi~)hy  of  the  adipose  tissue,  the  cells  are  filled 
to  distension  with  fat ;  and  in  extreme  cases  of  its  general  hyper- 
trophy— as  those  mentioned  on  page  300 — new  cells  are  doubtless 
formed  in  great  numbers,  together  with  an  extension  of  the  vessels, 
and  the  matrix  of  areolar  tissue ;  in  other  words,  there  is  a  new 
formation  of  this  tissue.  In  those  cases,  also,  the  accumulation  in- 
terferes with  the  action  of  the  muscles,  and  the  general  nutrition  is 
impeded.  Occurring  in  infants  at  the  breast,  it  produces  an  impo- 
verishment of  the  blood,  frequently  causing  death  rapidly  and  un- 
expectedly. {Engel) 

The  hypertrophied  fat  occurring  in  drunkards  is  soft,  unctuous, 
of  a  grayish- white  color  and  mawkish  smeU;  and  it  not  unfre- 
quently  presents  similar  characters  in  persons  who  have  been  cured  ■ 
of  secondary  syphilis.  In  cancerous  deposits,  especially  in  the  skin 
and  subcutaneous  areolar  tissue,  abundant  deposits  of  firm,  granular, 
deep-yellow  fat  also  obtain.  {Engel.) 

III.  The  adipose  tumor  (Lipoma)  is  to  be  regarded  as  a  new  forma- 
tion of  the  adipose  tissue.  So,  also,  are  various  forms  of  Steatoma. 
If  entirely  removed  in  these  cases,  it  is  not  reproduced.  In  the 
Lipoma,  some  of  the  fat-cells  may  be  of  enormous  size  (even  y|g  of 
an  inch  or  more  in  diameter),  mixed  with  others  of  the  "normal  size. 
As  the  new  formations  of  fat-cells  never  take  place  without  that  of 

the  areolar  tissue,  the  density  of  a  fatty 
tumor  depends  upon  the  relative  amount 
of  the  latter.  (Fig.  194.)  When  the  fat- 
cells  are  gradually  replaced  by  a  fibrous 
tissue,  a  lardaceous  growth  (Steatoma)  is 
produced. 

Fat-cells  are  also  met  with  imbedded 
in  other  tumors,  as  in  polypus  uteri, 
throughout  which  they  are  sometimes 
disseminated.  The  Lipoma  arborescens 
{J.  Muller),  rather  frequently  occurring 
in  the  knee-joint,  is  to  be  regarded  as  a 
new  formation  of  fat-cells  in  addition  to 
those  normally  existing  in  the  adipose 
ligament,  so  called,  of  that  articulation. 
Encysted  tumors  are  also  found  con- 
taining fat,  but  in  the  form  of  globules  and  granules,  and  not  in 
cells.  These  are,  therefore,  not  modifications  of  adipose  tissue.  The 
■Cholesteatoma  {J.  Muller)  is  the  most  common.  Here  the  cyst  or 
sac  is  lined  with  a  delicate  epithelium,  and  filled  with  concentric 
laminaa  consisting  of  strata  of  cells  resembling  those  of  sheep's  fat 


Fig.  194. 


structure  of  a  fatty  tumor  (Lipoma) 
removed  from  tlio  back.  a.  Isolated 
cells,  sliowingthe  crystalline  nucleus, 
margaric  acid.  (Bennett.) 


Becquerel  and  Rodier. 


ADIPOSE   TISSUE. 


309 


(though  only  one-half  as  large  in  diameter) ;  and  between  which 
lamina3,  crystals  of  cholesterine  are  found  in  abundance. 

Fig.  195. 


Cholesteatoma  of  the  brain,  consisting  of  layers  of  epidermis-lilie  cells,  mostly  ■vrith  a  parietal 
nucleus.  Cholesterine  plates  are  disseminated  among  the  layers  of  the  cells. — Magnified  3.50  diame- 
ters.   (Wedl.) 

Fatty  Degeneration,  or  Stearosis. 

The  phrase  "fatty  degeneration"  suggests  the  idea  that  certain 
parts  or  organs  have  been  converted  into  fat,  or  into  adipose  tissue. 
Neither  of  these  ideas  is,  however,  correct.  An  organ  in  a  state  of 
fatty  degeneration  is  one,  some  or  all  of  whose  structural  elements 
have  been  replaced  hy  fat,  in  the  form  of  glohules  or  granules,  and  not 
inclosed  in  fat-cells.  (Fig.  40.)  This  subject  has,  therefore,  no  histo- 
logical connection  with  the  adipose  tissue;  but  it  is  introduced  here 
to  insure  a  correct  understanding  of  it,  as  contrasted  with  the  patho- 
logical formations  of  adipose  tissue. 

Fatty  degeneration,  or  stearosis,  most  frequently  occurs  in  the 
following  organs : — 

1.  In  the  hones,  stearosis  is  usually  inaptly  termed  osteomalacia,  or 
mollities  ossium.'  In  this  disease  the  osseous  matter  disappears,  and 
the  interstices  thus  formed  are  filled  with  fat-globules ;  and,  on  ma- 
ceration, the  bone  seems  to  consist  of  a  mere  gauze-like  tissue.  The 
lacunte  also  become  enlarged,  and  the  pores  less  distinct.     Fig.  196 

Fig.  196. 


a.  Lacuna  and  pores  of  bone  in  the  normal  state,  h.  Enlarged  as  in  mollities  ossium.  (Dalrymple.) 


'  Mollities  ossium  may  also  result  from  other  diseases  ;  e.  g.  from  cancer  of  boue. 


310  THE   TISSUES. 

shows  their  appearance  as  compared  with  the  normal  state.  In  an 
extreme  case  of  mollities  ossium,  Lehmann  found  in  the  ribs  the 
following  elements,  in  100  parts: — 

Fat 56.92 

Other  organic  matters  ....  24.665 

Phosphate  of  lime         ....  15.881 
Carbonate  of  lime        ....       2.534 

2.  In  fatty  degeneration  of  the  heart,  only  one  or  two  fat-globules 
at  first  appear  within  the  myolemma  of  the  fibres;  but,  finally,  in 
some  cases  the  whole  fibre  is  occupied  by  them.  Then  the  fibres 
become  fused  together  into  a  more  or  less  opaque  mass,  in  which 
nothing  of  the  original  tissue  can  be  traced.  Fig,  259  shows  the 
incipient  and  the  most  advanced  stage  of  this  disease. 

An  accumulation  of  the  fat-cells  naturally  existing  under  the 
pericardium  and  in  contact  with  the  heart,  especially  if  it  also  in- 
sinuates itself  somewhat  between  the  muscular  fasciculi  and  fibres, 
is  often  mistaken  for  fatty  degeneration.  But  the  microscope  shows 
the  fat  to  be  in  the  ordinary  fat-cells,  and  of  the  average  size  of  g^o 
of  an  inch  in  diameter;  while  in  true  stearosis,  the  fat-drops  vary 
from  a  mere  microscopic  point  to  ^no^  of  ^'^  i^^ch  in  diameter,  and 
are  contained  within  the  myolemmata. 

3.  In  case  of  stearosis  of  paralyzed  muscles  also,  the  change  just 
mentioned  occurs ;  oil-globules  being  contained  within  the  myolem- 
mata (instead  of  the  fibrillar  hereafter  to  be  described),  and  the 
stria3  having  disappeared. 

But  stearosis  also  occurs  in  smooth  muscular  fibre,  at  least  in 
that  of  the  uterus  during  its  atrophy  after  parturition.  Here,  also, 
as  Kolliker  has  demonstrated,  the  fibre-cells  become  gradually  filled 
with  fat-drops;  after  which  some  entirely  disappear,  while  others 
are  reduced  to  their  size  previously  to  gestation. 

4.  In  fatty  degeneration  of  the  kidney,  the  fat-drops  exist  partly 
in  the  epithelial  cells  of  this  organ,  and  partly  in  a  free  state  among 
them.  The  disease  affects  the  cortical  substance  more  especially. 
Sometimes  the  epithelial  cells  are  found  detached,  and  the  urinifer- 
ous  tubes  entirely  filled  with  fluid  fat. 

Oppoltzer  conjectured  that  the  urine  contains  fat  whenever  there 
is  stearosis  of  the  kidney;  which,  if  correct,  would  prove  a  great 
aid  in  diagnosis.  Lehmann,  however,  never  found  fat  in  the  urine 
in  this  disease,  except  in  a  single  instance.  The  fat  globules  some- 
times seen  in  the  urine  of  women,  frequently  proceed  from  the 


ADIPOSE   TISSUE.  311 

external  genitals.     They  are  sometimes,  but  not  invariably  found 
in  the  urine  durincr  slow  fevers. 

It  should  be  borne  in  mind  that  the  human  kidney  naturally  con- 
tains a  small  quantity  of  fat.  {Frerichs.)  Prof.  Beale*  has  also  shown 
that  in  diabetes  the  kidney  is  in  a  state  of  comparative  stearosis — 
or  increase  of  fat.  The  normal  amount  of  fat  being  3.98  parts  out 
of  100  of  the  solid  matter  of  the  kidney,  from  three  to  five  times 
as  much  was  found  in  the  diabetic  kidney;  and  rather  more  than 
six  times  as  much  (26.97)  in  a  case  of  actual  stearosis.  On  the 
other  hand,  the  liver  in  diabetes  contains  only  from  about  one-third 
to  one-half  of  its  normal  amount  of  fat.  It  is  thus  in  a  state  op- 
posed to  fatty  degeneration. 

5.  The  cells  of  the  liver  naturally  contain  a  few  minute  oil-drops 
imbedded  in  a  mass  of  granular  matter;  the  fat  amounting,  accord- 
ing to  Prof.  Beale,  to  from  12.15  to  15.81  out  of  100  parts  of  the 
solid  matter  in  this  organ.  In  fatty  degeneration,  the  cells  are  filled 
to  the  extent  of  one-half  or  two  thirds;  and  are  sometimes  com- 
pletely engaged  with  colorless  fluid  oil;  the  whole  liver  in  some 
cases  containing  but  24.93  per  cent,  of  water,  and  75.07  of  solid 
matter — of  which  latter  65.19  per  cent,  is  fatty  matter.  A  yellow 
matter  is  also  sometimes  seen  mixed  with  the  oil.  The  nuclei  of 
the  cells  disappear,  and  the  cell-wall 
sometimes   becomes   thickened    and  ^^' 

striated.    In  advanced  cases,  the  cells 
are  found  even  to  be  broken  up  and      ^x-— ->^         '{j/T^  *^«'o^' 


lost,  and  their  place  is  occupied  by 
granules,  among  which  are  multi- 
tudes of  oil-drops  of  various  sizes. 
(Fig.  197.) 

The  cells  being  enlarged  by  the 
increased  amount  of  oil,  the  whole       r.  ^.    ^         .•       f  *i    ,• 

'  _  Fatty    degeneratiou    of   the  liver,      a. 

liver  undergoes  an  increase  of  size,     Empty  ruptured  ceii  from  winch  the  oii 

1,1  •        ,  11"  1       has  escaped,    b,  c,  d,  e.  Hepatic  cells  con- 

and  the  mmute  vessels  being  pressed    t^,,,,^  ^^,^ ,,,/ 

by  the  development  of  the  cells,  it 

also  becomes  paler  than  usual.     It  also  is  found  to  secrete  less  sugar, 

though  the  amount  or  quality  of  the  bile  seems  not  to  be  essentially 

modified,  as  a  constant  result. 

There  is  reason  for  the  belief  that  fatty  degeneration  of  the  liver 

'  British  and  Foreign  Medico-Chirurgical  Review,  vol.  xii.  p.  22(3. 


312 


THE   TISSUES. 


may  be  produced  by  an  excess  of  fatty  elements  in  the  food;  espe- 
cially if  combined  with  inactive  habits.  This  state  of  the  organ  is 
directly  produced  in  fowls,  by  keeping  them  quiet  (hence  a  dark 
place  is  better),  and  cramming  them  with  oily  food;  as  in  produc- 
ing the  livers,  of  which  to  make  the  pate  de  foie  gras.  No  such 
connection  is,  however,  known  to  exist  between  the  food  and  fatty 
degeneration  of  the  other  organs  mentioned. 

6.  Something  very  analogous  to  fatty  degeneration  also  occurs  in 
arteries;  being  termed  atheroma.  It  is  a  deposit  in  the  middle  coat 
of  the  artery,  and  visible  through  the  inner  coat,  of  a  pulpy  dif- 
fluent substance,  and  which  has  sometimes,  therefore,  been  mis- 
taken for  pus.  Some  authors  maintain,  on  insufficient  grounds,  it 
is  believed,  that  fibrine  merely,  is  first  deposited  in  consequence  of 
arteritis;  and  that  atheroma  is  merely  a  fatty  degeneration  of  the 
fibrine,  and  not  of  the  arterial  coat  itself.  It  consists  principally 
of  fat-drops  with  crystals  of  cholesterine.     Figs.  198  and  199  show 


Fig.  198. 


Fig.  199. 


I 

Fig.  IDS.  Early  stage  of  atheroma. 

Fig.  199.  Fatty  granules  with  crystals  of  cliolesterino  from  atheromatous  deposits  in  the  aorta. 
{Bennett.) 

its  appearance  in  the  early  and  in  the  advanced  stage.  It  conforms 
to  the  law  of  symmetry  in  a  remarkable  degree ;  occurring  gene- 
rally in  the  two  arteries  of  the  same  name  at  the  same  time,  e.  g. 
the  two  iliacs,  and  the  carotids.  It  is  most  common  in  the  aorta, 
and  the  divisions  of  it  nearest  the  heart. 

7.  Fat  abounds  in  encephaloid  cancer;  being  here  also  in  the 
form  of  drops. 


CARTILAGE. 


813 


CHAPTER   VI, 


CARTILAGE, 


Cartilage  is  sometimes  a  simple,  but  generally  a  compound  tis- 
sue. It  is  described  bere  more  especially  because  of  the  advantage 
of  a  knowledge  of  the  structure  of  cartilage  as  preliminary  to  that 
of  the  development  of  bone. 

Cartilage  is  a  solid,  elastic,  bluish,  milk-white,  or  yellowish  sub- 
stance, presenting  two  varieties : — 

1.  Simple  cellular  cartilage. 

2.  Compound  cartilage;  consisting  of  cells  and  a  homogene- 

ous intercellular  substance. 

1.  Yery  few  instances  of  the  simple  cellular  cartilage,  or  cartilage 
without  interstitial  substance,  occur  in  the  adult  mammal.  To  this 
class,  however,  belong  the  chorda  dorsalis  of  the  human  embryo, 
and  of  many  adult  fishes.  Many,  indeed,  of  the  foetal  cartilages 
are  merely  cellular;  as  are  also  the  gill  laminae  of  fishes  in  part, 
and  those  of  the  external  ear  of  many  mammalia.  Fig.  200  shows 
the  cells  of  the  chorda  dorsalis  of  the  lamprey,  and  Fig.  201,  the 
cellular  cartilage  of  the  mouse's  ear. 


Fisr.  200. 


Fig.  201. 


Fig.  200.  Four  nucleated  cells  from  tlio  chorda  dorsalis  of  the  lamprey.     1.  Nucleus  with  nucleo- 
lus.    2.  Another,  seen  in  profile. 
Fig.  201.  Cellular  cartilage  of  mouse's  ear. 


2.  The  compound  cartilages  (those  with  intercellular  substance), 
are  of  two  kinds :  1.  True  cartilage  (or  hyaline  cartilage),  the  inter- 
cellular substance  being  homogeneous,  and  yielding  chondrine  on 


814 


THE   TISSUES. 


Section  of  fibro-cartilage  ;  showing  disposition  of  car- 
tilage-cells in  areola3  of  white  fibrous  tissue. 

Fig.  203. 


boiling.  2.  Those  with  a  fibrous  intercellular  substance;  either 
white  fibrous  tissue,  or  elastic  tissue.  The  latter  are  termed  fibro- 
cartilage^  in  case  the  intercellular  substance  is  white  fibrous  tissue 

(Fig.  202);  and  reticular  carti- 
^^'       '  lags  (or  yellow  cartilage),  if  it 

be  the  elastic  tissue.  This 
last  form  of  fibro-cartilage  is 
found  in  the  external  ear,  and 
the  cartilaginous  portion  of 
the  Eustachian  tube,  and  in 
the  epiglottis.  The  cartilages 
of  Santorini  and  Wrisberg 
(of  the  larynx),  and  that  on 
the  condyle  of  the  lower  jaw, 
are  of  this  class.  The  struc- 
ture of  the  reticulated  carti- 
lage is  shown  by  Fig.  203. 
Hoppe  found  that  the  reticu- 
lated cartilages  yield  chon- 
drine  in  small  quantity  on 
boiling.  He,  however,  main- 
tains that  this  substance  is  not 
derived  from  the  cells,  nor 
from  the  elastic  fibres,  but 
from  athird(achondrine  yield- 
ing) substance,  surrounding 
the  cells.  Indeed,  from  his 
conclusions  in  regard  to  carti- 
lage-cells, he  was  led  to  the 
axiom  that  cell-membranes 
and  cell-contents  never  consist  of  gelatigenous  substance  (osteine  or 
cartilageine) ;  and  can  never  be  metamorphosed  into  it. 

Fibro-cartilage  yields  only  glutin,  since  the  white  fibrous  tissue 
constitutes  its  intercellular  substance.  All  the  intra-articular  fibro- 
cartilages  are  of  this  kind.  Its  structure  has  been  shown  by  Fig. 
202. 

•True  Hyaline  Cartilage. 
True  cartilage  consists  of  (1),  cartilage-cells,  and  (2)  a  hyaline  (or 
usually  granular)  homogeneous  substance  (p.  108). 


Kcticulated   cartilage;    human  epiglottis 
350  diameters.  (Kolliker.) 


-JIagiiified 


CAKTILAGE,  315 

The  relative  amount  of  these  two  elements  varies  much  in  differ- 
ent cartilages;  either  element  alone  also  sometimes  constituting 
almost  the  whole  mass. 

1.  Cartilage-ceZ^s  present  no  peculiarities  in  form,  being  rounded 
or  elongated,  flattened,  or  fusiform,  and  very  rarely  stellate,  as  in 
enchondroraa,  and  in  cuttle-fishes  and  sharks.  From  1  to  4  (or 
even  20  to  30)  cells  exist  together  in  a  single  cavity^  in  the  inter- 
cellular substance;  and  sometimes  they  are  arranged  in  regular  rows, 
as  in  cartilages  in  wliicb  bone  is  about  to  be  developed.  (Fig.  225.) 

The  cell-walls  are  usually  thick,  and  frequently  are  invested  by 
concentric  laminas.  They  are  not  dissolved  by  boiling,  and  long 
resist  alkalies  and  acids;  thus  resembling  the  elastic  but  not  the 
collagenous  tissue  (p.  282). 

The  contents  are  clear  and  fluid ;  in  which,  generally,  but  not 
always,  one  or  many  fat-globules  are  contained.  They  coagulate  in 
water  and  dilute  acids,  and  are  readily  dissolved  by  alkalies.  Some- 
times the  fat-globules  are  so  numerous  as  to  render  the  nucleus  in- 
visible.    But  a  single  nucleus  is  contained  in  each  cell. 

2.  The  intercellular  (or  interstitial)  liomogeneous  suhstance  is  some- 
times hyaline,  but  generally  finely  granulated.  It  is  permeated  by 
a  peculiar  fluid  which  has  not  yet  been  investigated.  {Lehmann) 
Fat-globules  are  also  often  found  in  it. 

Finally,  the  permanent  cartilages  are  invested  by  a  fibrous  mem- 
brane, the  'pericliondrium,  {e.  g.  costal  cartilage).  This  is  less  vascu- 
lar than  the  analogous  sheath  of  the  bones — the  periosteum,  (p. 
279,  4.) 

Chemical  Composition  of  true  Cartilage. 
The  chemical  characters  of  cartilage  are,  in  some  respects,  very 
little  known.  It  is  certain,  however,  that  the  cells  and  the  inter- 
cellular substance  are  different.  The  latter  is  converted,  partially 
at  least,^  by  boiling  into  chondrine^  in  case  of  the  true  cartilages, 
and  is  itself  cartilageine^  as  has  already  been  seen  (p.  99).  In  reti- 
culated cartilage  chondrine  exists  in  small  amount  {Hoppe),  and  pro- 
bably also  elasticine  (p.  100). 

'  Kolliker  cand  others  term  these  cavities  the  cartilaije-cdls,  and  the  true  cells 
just  described,  the  secondanj  cells  or  nuclei.  We  adopt  Robin's  view  as  the  correct 
one. 

^  Lehmann  infers  from  its  behavior  towards  concentrated  suliiburic  acid  that  the 
intercellular  substance  contains  three  different,  though  allied  substances. 


316  THE   TISSUES, 

What  are  the  precise  cliernical  characters  of  the  cartilage-cells 
and  their  contents,  is  unknown. 

The  amount  of  water  varies  in  the  difi'erent  true  cartilages  be- 
tween  54  and  70  per  cent.  [Lehmann);  and  exerts  an  important 
influence  on  their  physical  properties. 

The  fat  constitutes  from  2  to  5  per  cent,  of  the  dry  cartilage. 
Mulder  first  proved  that  a  small  amount  of  sulphur  is  combined 
with  the  chondrine  (cartilageine).  It,  therefore,  probably  exists  in 
the  intercellular  substance  alone.  In  the  costal  cartilages  from  3  to  6 
per  cent,  of  mineral  substances  have  been  found,  viz.,  phosphates  of 
lime  and  magnesia,  chloride  of  sodium,  carbonate  of  soda,  and  a 
large  amount  of  sulphates.  The  chloride  of  sodium  varies  ex- 
tremely in  the  ash  of  cartilage  (from  1  to  8  per  cent.) ;  there,  how- 
ever, being  more  of  it  in  cartilage  than  in  any  other  tissue.  [Leh- 
mann.) These  variations  suggest  the  idea  that  it  is  combined  not 
with  the  histological  elements  of  the  cartilage,  but  exists  in  the 
peculiar  fluid  which  permeates  the  intercellular  substance. 

Properties  and  Uses  of  Cartilage. 

True  cartilage  manifests  only  physical,  and  no  vital  properties, 
in  the  organs  of  which  it  forms  a  part ;  viz.,  solidity  and  elasticity. 
When  fully  developed,  cartilages  contain  no  vessels  at  all ;  and 
hence  constitute  an  extra-vascular  tissue,  like  the  cornea  and  epi- 
thelium and  its  modifications  (p.  281).  Nor  do  they  contain  lym- 
phatics or  nerves.* 

Uses. — The  uses  of  the  true  cartilages  depend  on  the  two  proper- 
ties just  noticed.  Ilence  they  are  found  where  a  tissue  is  required 
to  resist  pressure,  as  in  the  articular  cartilages ;  whose  elasticity  and 
insensibility  (from  possessing  no  nerves)  are  at  the  same  time  put 
into  requisition.  The  costal  cartilages  aftbrd  sufficient  strength  for 
the  walls  of  the  thorax,  while  their  flexibility  and  elasticity  favor 
the  movements  of  respiration.  The  cartilages  of  the  nose  afford 
to  that  organ  the  requisite  firmness  and  flexibility. 

Finally,  cartilages  exist  in  the  embryo  instead  of  bones ;  and 
which  finally  assume  the  form  of  the  bones  to  be  subsequently  de- 
veloped. These  subsequently  giving  place  to  the  bones,  and  thus 
disappearing,  are  termed  temporary  cartilages,  and  in  their  aggre- 
gate, constitute  the  cartilaginous  skeleton ;  while  the  others  in  the 

'  In  tlio  septum  iiarium  of  tlie  calf,  KilUiker  found  both  arteries,  and  small  nerv- 
ous twigs.     Tlio  costal  cartilages  also  contain  a  few  vessels. 


CAETILAGE.  317 

body  are,  in  coDtradistinctioa  from  these,  called  permaneyU  carti- 
lages— e.  g.  articular  cartilages,  costal  cartilages,  «&c. 

Development  of  Cartilage. 

True  cartilage  originates  in  cells  not  distinguishable  at  first  from 
those  from  which  the  other  tissues  arc  developed.  Between  these 
cells  a  hyaline  substance  is  deposited,  which,  on  being  boiled,  be- 
comes chondrine ;  and  which  usually  increases  simultaneously  with 
the  bulk  of  the  cells.  Thus,  the  original  cells  are  pushed  further 
and  further  asunder. 

But  new  cells  are  also  produced  from  germs  in  the  hyaline  sub- 
stance ;  while  at  the  same  time  the  original  ones  are  multiplied  by 
bipartite  and  tripartite  subdi- 
vision (p.  126).  Thus,  it  is 
very  common  to  meet  with 
groups  of  two,  three,  or  four 
cells  (or  more)  in  a  single  ca- 
vity, as  shown  by  Fig.  204. 

If  the  intercellular  substance 
consist  of  collagenous  fibres, 
a  fibro-cartilage  results.  And 
sometimes  the  cells  entirely 
disappear,  and   the  whole  re- 

mainino"    mass   is  fibrous.      The        section  of  the  brancliial  cartilage  of  tadpole,     a. 
.  Groiip  of  four  cells,  separating  from  each  other,     h. 

fibres   are    developed    in   the  pair  of  ceiis  in  apposition,  c,  c.  Nuclei  of  cartilage- 
external  portions  first.     When    '=^l'^-    rf-  Cavity  containing  three  cells. 

elastic  fibres  are  developed  from  the  intercellular  substance,  a  reti- 
culated cartilage  results. 

The  growth  of  cartilage  is  secured  both  by  the  reduplication  of 
the  cells,  and  the  increase  of  the  intercellular  substance.  The 
plasma  doubtless  permeates  tbe  intercellular  substance,  and  the 
peculiar  fluid,  before  alluded  to,  is  probably  a  modified  plasma,  and 
contains  the  elements  for  the  nutrition  of  the  cartilage.  The  car- 
tilage-cavities of  the  new-born  infant  are  three  or  four  times  as 
numerous  as  in  the  foetus  of  four  months;  but  the  intercellular 
substance  is  now  double  the  bulk  of  the  cavities,  while  at  the  latter 
period  it  hardly  exceeds  the  latter — at  least  in  the  costal  cartilages. 
After  birth,  the  cavities  (and  contained  cells)  and  the  intercellular 
substance,  increase  in  pretty  nearly  an  equal  ratio.  According  to 
Harting,  the  cavities  (and  contents)  are  8  to  12  times  larger  in  the 
adult  than  in  the  infant  at  birth. 


318 


THE   TISSUES. 


As  cartilage  contaius  no  vessels,  very  slight  nutritive  changes 
probably  occur,  after  it  once  attains  to  its  full  development. 

Cartilage,  if  removed,  is  never  regenerated.  AVhite  fibrous  tis- 
sue is  developed  instead,  to  fill  up  the  breach ;  or  a  cretification  of 
the  entire  cartilage  may  take  place.  {Dr.  Redfern?)  The  costal  car- 
tilages, if  fractured,  are,  however,  repaired  by  osseous  union.  These 
cartilages  are  normally  ossified  in  some  of  the  lower  animals,  and 
are  not  seldom  ossified  in  the  latter  period  of  life,  in  the  human 
subject. 

Articular  cartilages  are,  in  the  foetus,  covered  by  an  epithelium. 
This  appears  to  be  destroyed  after  birth  by  pressure  and  attrition. 
While  it  exists,  vessels  are  found  between  it  and  the  cartilage;  and 
which  subsequently  return  to  the  circumference  of  the  latter.  Their 
appearance  before  and  after  birth  is  shown  by  Figs.  205  and  206. 

Fig.  205. 


Vessels  situated  between  tliu  .>u..lL.  l;  .-yuuvial  iiu  iiibrane  and  the  articular  cartilage,  at  the  point 
where  the  ligameutum  teres  is  inserted  in  the  head  of  the  os  femoris.  Human  fcetus  between  3  and 
4  months,  n.  The  surface  of  the  articular  cartilage,  h.  The  ves.sels  between  tlie  articular  cartilage 
and  the  epithelial  layer,  c.  The  surface  to  which  the  ligaraentum  teres  was  attached,  d.  Tlic  vein. 
p..  The  artery. 

Their  connection  with  the  bones  will  be  explained  in  the  following 

chapter. 
Fig.  206.  In  the  costal  cartilages,  vas- 

cular canals  are  found  at  large 
distances  from  each  other,  and 
which  are  lined  by  prolonga- 
tions of  their  perichondrium, 
and  narrow  cartilage-cells.  The 
vessels,  however,  nowhere  pass 
from  the  walls  of  those  canals 

Vessels   with    rnricoso    dilatations  surr  k  •     i.       xI  i     i  />   xi 

edges  of  the  articular  cartilages,  after  L.  ,„.  ^^^O    the    SUbstaUCC  of    thc  Car- 


CARTILAGE. 


319 


tilage,  and  they  usually  do  not  anastomose  witli  each  other.  Similar 
canals  are  also  seen  in  the  temporary  cartilages  near  the  points 
where  the  process  of  ossification  is  going  on. 

The  changes  undergone  by  the  cartilaginous  skeleton,  will  be  spe- 
cified under  the  head  of  the  development  of  bone. 

Pathological  States,  and  New  Formations  of  Cartilage. 

1.  As  cartilage  normally  contains  no  vessels,  nor  passages  for  the 
circulation  of  plasma  (like  bone  and  the  cornea),  it  can  hardly  be 
regarded  as  capable  of  being  attacked  by  inflammation.  It  is,  how- 
ever, susceptible  of  ulceration,  or  a  gradual  removal  of  its  substance, 
and  in  this  condition  appears  to  become  vascular  on  the  eroded  sur- 
face. The  vessels  are,  however,  not  in  the  substance  of  the  carti- 
lage, but  in  a  membranous  expansion  which  is  formed  de  novo  on 
its  rough  surface. 

2.  The  loose  cartilages,  so  called,  which  are  often  found  in  joints 
(especially  the  knee-joint),  are  not  actual  cartilages,  but  merely  the 
non-vascular  processes  of  the  synovial  membrane,  which  increase 
in  size  and  solidity  and  then  become  detached  from  the  vascular 
folds.  Sometimes,  however,  they  are  mere  fibrinous  exudations,  or 
solidified  deposits  from  the  synovia,  as  Yirchow  has  shown. 

3.  A  new  formation  of  cartilage  constitutes  enchondroma.  It 
occurs  in  bone  more  frequently  than  in  any  another  normal  tissue. 
The  bones  of  the  fingers  and  toes  are  most  liable  to  it,  though  the 
ribs,  sternum,  and  vertebrae  are  not  exempt;  and  the  cranium,  the 
ilium,  and  the  long  bones  have  been  attacked  by  it. 

Enchondroma  may  originate  on   the  surface  of  bone,  or  in  the 


Fig.  207. 


Fiff.  209. 


^-<. 


Fig.  207.  TUia -section  ot  tlii.circumti.icuci.ot  au  euchoudioma  luiu  tho  jcUis. 

Fig.  208.  Cells  from  the  softened  part  of  the  same  tumor. 

Fig.  209.  The  same,  after  the  addition  of  acetic  acid.    [Bennett.) 

cancellated  tissue.     It  usually  grows  slowly  and  seldom  exceeds  an 
orange  in  size.     It  is  not  attended  by  pain  or  disorganization  of  the 


320 


THE    TISSUES. 


Enchondroma ;  microscopic  structure. 
Lebert ) 


[After 


surrounding  parts.      It,  however,  sometimes  ulcerates  and  pours 

out   an    exhaustinor    discharge. — 

p;—     210  V  ^ 

^*       ■  When  externally  situated,  it  is  lo- 

bulated  and  surrounded  by  an  ex- 
pansion of  the  periosteum.  When 
internal,  it  presents  a  semi-elastic 
feel,  and,  on  section,  the  knife 
passes  through  a  thin  crackling 
shell  of  bone,  and  then  shows  a 
white  cartilaginous  mass;  which 
on  microscopic  examination,  some- 
times cannot  be  distinguished  from 
true  cartilage,  and  at  others  resem- 
bles fibro-cartilage.  Figs.  207,  208, 
and  209  show  the  structure  of  the 
first  variety;  and  Fig.  210,  that 
which  resembles  fibro-cartilage. 
The  former  yields  chondrineon  boil- 
ing, and  the  latter  glutin.  The 
external  variety  has  no  investment 
of  bone,  and  is  met  with  chiefly  in  the  pelvis,  cranium,  and  ribs. 

Enchondroma  generally,  but  not  always,  manifests  no  disposition 
to  ossification.  It  is  chiefly  met  with  in  early  life,  and  Miiller  has 
shown  that  it  is  generally  due  to  mechanical  injury  interfering  with 
the  development  of  bone  at  the  period  when  ossification  occurs  and 
bone  is  formed;  and  the  process  usually  commences  at  the  point  of 
attachment  of  the  growth  to  the  bone  on  which  it  is  developed. 
When  com])letely  ossified,  the  enchondroma  becomes  an  exostosis. 

4.  Atrophy  of  cartilage  is  not  uncommon.  Here  the  hyaline  in- 
tercellular substance,  especially  in  case  of  the  articular  cartilages,  is 
replaced  by  a  soft  ligamentous  or  fibrous  structure,  easily  scraped 
by  the  knife,  and  of  a  dirty  brownish-yellow  color,  the  fibres  disap- 
pearing under  the  action  of  acetic  acid.  The  cartilage-cells  become, 
at  the  same  time,  more  or  less  filled  with  fat-globules.  The  inter- 
vertebral cartilages  of  aged  persons  are  usually  of  a  dusky  color, 
and  dry;  the  intercellular  substance  being  also  fibrous,  and  contain- 
ing pigment-cells.  Atrophy  of  the  articular  cartilages  may  be  pro- 
duced by  cancer  or  sarcoma,  when  occurring  near  them  in  the  ex- 
tremities of  the  bones. 

5.  Necrosis  (or  death)  of  cartilage  occurs— as  in  the  cartilage  of 
the  larynx — from  inflammation  of  the  perichondrium  (perichondri- 
tis— Alhers).  A  formation  of  pus  in  the  cancelli  of  the  articular 
extremities  of  bone,  often  produces  necrosis  of  the  articular  car- 
tilages. 

6.  Cartilage  is  liable  to  fatty  degeneration,  this  affecting  both  the 
cells  and  the  intercellular  substance;  both  losing  their  transparency, 
and  ultimately  becoming  wholly  unrecognizable.  Suppuration  in 
tke  contiguous  bone  sometimes  produces  this  efiect. 


OSSEOUS   TISSUE.  321 


CHAPTER   VII. 

OSSEOUS   TISSUE,  AND  THE   BONES. 

Osseous  tissue  is  peculiar  to  the  bones  and  teeth,  and  will  be 
first  described ;  after  which  the  structure  of  the  bones,  consisting 
as  they  do  of  the  osseous  and  several  other  tissues  blended  together, 
will  be  specified. 

SECTION  I. 
OSSEOUS   TISSUE. 

To  the  naked  eye  the  bones  present  two  forms  of  the  osseous 
tissue — viz.,  the  compact^  and  the  cancellated  or  spongy.  But,  how- 
ever important  these  distinctions  are  in  a  practical  point  of  view, 
microscopic  examination  shows  them  to  be  essentially  identical,  as 
will  be  seen. 

The  ultimate  histological  element  of  the  osseous  tissue  is  a  pale, 
oval,  oblong,  or  angular  granule,  gJjj^  of  an  inch  in  diameter. ' 
{Kolliker.)     These  granules  (Fig.  211)  are  blended 
together  so  as  to  form  membraniform  expansions  of        Fig-  211. 
varying  thickness  (the  lamellse),  or  irregular  masses      *=-?'#^°'^* 
inclosing  cavities  of  a  peculiar  form  (the  lacunas  and       '}»J^W'''% 
pores);  and  from  the  different  conformations  and  ar-       '^i^^'^P 
rangements  of  these  lamellae  and  masses,  result  the       *?^^i'ae«' 
compact  and  the  cancellated  bone-substance  already     ultimate  grannies 

.  I  of    bone,    Isolated, 

mentioned.  ^^a  m  small  mass- 

The  thinnest  lamellse  or  a  simple  plate  of  bone  is  es ;  from  the  femur, 
formed  by  the  apposition  at  their  margins  of  a  single  ameters.  (Tomes.) 
stratum  of  granules.  It  must  be  remembered,  how- 
ever, that  the  osseous  tissue  is  not  always  granular.  It  is  sometimes 
a  perfectly  clear  hyaline  substance.  This  form  appears  to  be  a  more 
recent  and  less  perfect  development  than  the  granular ;  and  both 
often  appear  in  the  same  bone,  and  even  in  the  same  lamella  of  an 

'  5oV(T  ^°  TToffc  ^^  ^^  iuch.  {Todd  and  Bowman  )  One-sixth  to  one  fifth  tlie 
diameter  of  the  blood-corpuscles.   {Tomes.) 

21 


322  THE   TISSUES. 

Haversian  rod.  lu  the  latter  case  the  lamina  is  seen  to  consist  of 
two  distinct  layers — an  external  granular,  and  an  internal,  hyaline. 
As  a  general  rule,  no  particle  of  osseous  tissue  is  found  more 
than  y^5  of  an  inch  from  a  bloodvessel.  If,  therefore,  a  plate  of 
bone  be  not  more  than  double  this  thickness  (g'g  of  an  inch),  no 
vessels  will  be  found  to  enter  it ;  but  they  will  be  distributed  upon 
its  two  surfaces  only.  It  is,  however,  indispensable  for  the  nutri- 
tion of  bone  that  the  plasma  be  brought  more  nearly  than  this  to 
each  molecule  of  the  osseous  tissue;  and  for  this  purpose  cavities 
of  a  peculiar  form  (lacunae  and  pores)  are  hollowed  out  in  the  sub- 
stance of  all  but  the  thinnest  laminae  of  bone,  whose  forms  are 
shown  by  Fig.  212.     In  some  of  the  thinnest  bones  of  the  smallest 

Fig.  212. 


Two  lacunse  of  osseous  tissue  seen  on  the  surface,  showing  the  disposition  of  their  pores.  Tbo 
ultimate  granules  of  the  tissue,  both  on  their  walls  aud  around  them,  are  well  represented.  (Magui- 
fled  1,200  diameters.)    From  the  cancelli  of  the  femur.    (Tomes.) 

animals,  however — as  the  os  unguis  of  the  mouse  and  certain  small 
birds — even  these  cavities  do  not  exist;  every  molecule  of  the 
osseous  tissue  being  so  near  to  the  blood  in  the  vessels  distributed 
upon  the  surfaces  of  the  bone,  that  no  arrangement  for  the  trans- 
mission of  the  plasma  alone,  as  before  mentioned,  is  required.  Such 
a  bone  is  therefore  everywhere  granular  and  homogeneous  in  struc- 
ture, like  the  portions  between  the  pores  in  Fig.  212. 

If,  therefore,  a  layer  of  bone  is  not  more  than  gg'gj,  to  ^^'^j,  of 
an  inch  thick,  the  substance  is  solid ;  if  another  layer  be  superim- 
posed upon  this,  cavities  for  tlie  plasma  (lacunas  and  pores)  are 
formed  between  them,  or  in  their  substance ;  and  if  the  whole 
thickness  be  more  than  g'j  of  an  inch,  vessels  also  (the  Haversian 
vessels)  are  found  in  canals  traversing  it.  These  cavities  and  canals 
will  be  next  described. 


OSSEOUS   TISSUE. 


J23 


1.  The  Lacnnce  and  Pores  of  Osseous  Tissue. 

The  lacunce  (or  bone-corpuscles)  in  man  vary  but  little  in  size 

and  shape.     Most  of  them  are  shaped  like  a  melon-seed ;  though 

some  are  more  fusiform,  or  even  spherical.     Their  length  average? 

to  gjjj  of  an  inch ;  some  are,  however,  as  short  as  tt-qqjj  of  an 


1 

1  2oI) 


go  00  0 


1 tn 

T  5  0  0  0    ^^ 


Ficr.  213. 


inch,  and  some  as  long  as  ^^^  of  an  inch.  Tbey  are  ^^'^^  to  y^Vrn 
or  even  y^'^^  of  an  inch  broad;  and  from  g^'^g  to  goVo  of  ^.n  inch 
thick  or  deep.  Their  three  dimensions  are  usually  as  6  :  2  : 1.  The 
spherical  lacunas  are  from  20V0  to  ygVo  of  an  inch  in  diameter. 
They  are  placed  so  near  together  that  709  to  1120  (average  910) 
occur  within  a  surface  of  ^-g  of  an  inch  square.  {Harting) 

The  pores^  or  canaliculi,  average  J3V0  to  ^ip  of  an  inch  in  length, 
the  highest  extreme  being  g^^  of  an  inch.  They  are  jg^o^  to 
12^00  of  an  inch  in  diameter  at  their  origin  from  the  lacuna?,  and 
to  40^00  ^t  their  finest  extremities — the  average  being  about 
In  horizontal  sections  of  the  lacunse  they  appear  as  holes 
0  of  an  inch  apart.  In  transverse  sections  they  pro- 
duce the  radiating  stri^  from  being  viewed  in  several  planes,  and 
appear  to  be  somewhat  closer  together — or  yg^oo  to  y^ffoo  of  an 
inch  apart.  The  canaliculi  ra- 
diate from  the  lacunae  in  all  di- 
rections; and  are  branched  and 
irregular,  and  often  curved,  in 
their  course.  A  lacuna,  there- 
fore, together  with  its  radiating 
pores,  forms  an  imperfect  sphere, 
s^o  to  350  of  an  inch  in  diame- 
ter. The  pores  of  the  different 
lacunas  anastomose  freely  with 
each  other,  and  two  thus  con- 
nected sometimes  measure  3^0 
to  54o  of  an  inch  in  length. 
They  terminate  in  coecal  extre- 
mities only  on  limited  spots;  the  most  external,  opening  on  the  sur- 
face of  the  bone  (except  when  this  is  covered  by  cartilage  or  the 
insertion  of  ligaments  and  tendons),  as  shown  by  Fig.  213.  Thus- 
the  entire  structure  of  the  bones  is  everywhere  penetrated  by  a 
connected  system  of  cavities  and  pores,  by  which  the  nutritive  fluid 
from  the  vessels  is  carried  to  every  part. 


Portion  of  the  surface  of  the  tiljia  of  the  calf; 
seen  on  the  external  aspect.  The  numerous  point.-: 
are  the  openings  of  the  pores;  the  dark,  larger,  in- 
distinct spots  indicate  the  lacunR  to  which  the.'^e 
pores  belong,  appearing  from  a  greater  depth. — 
Magnified  360  diameters.  {Ki'lliker.) 


32-i  THE   TISSUES. 

Tomes  and  De  Morgan  (with  Virchow,  and  more  recently  Hoppe) 
assert  that  the  lacunae  and  pores  have  distinct  walls,^  as  is  the  case 
with  the  dentinal  tubuli.  Like  the  latter,  they  are  also  sometimes 
filled  up  with  a  solid  matter,  so  as  to  leave  only  a  small  space  in  the 
centre.  These  observers  also  found  a  modification  of  the  lacunae 
in  the  circumferential  laminae  of  bones;  they  there  being  elongated 
tubes,  and  passing,  in  bundles  or  singly,  more  or  less  obliquely, 
from  the  surface  towards  the  interior  of  the  bone.  The  largest  are 
sometimes  bent  once  or  twice  at  a  sharp  angle.  They  have  distinct 
walls,  and  are  connected  laterally  with  the  pores. 

The  contents  of  the  lacunae  are — first^  a  nucleus ;  and,  secondly^  a 
clear  fluid  ;  thus  resembling  the  contents  of  cartilage-cavities.  {Kol- 
Kker.)  Their  relation  to  the  cartilage-cells  will  be  explained  under 
the  head  of  "  Development  of  Bone."  The  fluid  is  doubtless  the 
nutritive  fluid  of  the  bone,  and  is  therefore  plasma,  or  a  modifica- 
tion of  it. 

The  lacunae  and  pores  do  not  present  precisely  the  same  condi- 
tions in  the  compact  and  the  cancellated  substance  of  bone,  as  will 
be  shown  (pp.  328  and  330). 

2.  The  Vascular  Canals  of  Osseous  Tissue. 

The  vascular  or  Haversian  canals  are  minute  tubular  passages 
in  the  bone-substance,  averaging  y^Vo  ^o  247  of  ^^  inch  (the  ex- 
tremes being  goVo  ^^^  s's)  5  ^^^^  which  exist  everywhere  in  the 
compact  bone-substance,  except  in  the  thinnest  layers  of  it,  forming 
a  network  similar  to  that  of  the  capillaries  in  the  soft  tissues. 

In  the  long  bones,  and  in  the  ribs,  clavicle,  os  pubis,  and  ischium, 
they  chiefly  run  parallel  to  the  long  axis  of  the  bone ;  and  almost 
always  either  parallel  to  the  surface,  or  perpendicular  to  it,  and  from 
ihu  to  g'j  of  an  inch  apart.  These  are,  however,  connected  by 
transverse  or  oblique  branches.  Thus  they  form  a  network  con- 
sisting of  elongated  and  generally  rectangular  meshes,  as  seen  in 
the  longitudinal  section  of  a  long  bone,  Fig.  214.  Few  transverse 
communicating  canals  occur,  however,  in  foetal  and  still  undeveloped 
bones. 

In  the  flat  bones,  almost  all  the  Haversian  canals  run  parallel  to 
their  surface,  and  sometimes,  indeed,  in  lines  radiating  from  one 
point  (as  the  parietal  protuberance,  upper  and  anterior  angle  of  the 

'  Lehmann  infers,  also,  from  IJoppe's  experiments,  that  the  lacunre  and  pores  are 
lined  by  an  albuminous  membrane,  insoluble  in  boiling  water. 


OSSEOUS   TISSUE. 


325 


Haversian  canals,  seen  on  a 
longitudinal  section  of  the  com- 
pact tissue  of  the  shaft  of  one  of 
the  long  bones.  1.  Arterial  ca- 
nal. 2.  Venous  canal.  3.  Dila- 
tation of  another  venous  canal. 


scapula,  articular  portion  of  the  ilium,  &c.). 
Less  frequently,  however,  they  are  parallel 
to  each  other — as  in  the  sternum. 

In  the  sJiori  bones  there  is  usually  one 
predominant  direction  for  the  Haversian 
canals;  they  being  vertical  in  the  vertebrae, 
and  parallel  to  the  long  axis  of  the  extre- 
mity, in  the  carpal  and  tarsal  bones.  In  the 
spinous  processes,  however,  as  in  the  cora- 
coid  and  styloid  processes,  the  canals  are 
arranged  as  in  the  shorter  cylindrical  bones. 

Finally,  a  few  Haversian  canals  exist  in 
the  walls  of  the  cancelli  of  bone,  but  only 
when  they  are  of  considerable  thickness. 

Since  the  Haversian  canals  contain  ves- 
sels, they  open— _/irs^,  externally  on  the  outer 
surface  of  the  bone ;  and,  secondly^  internally 
on  the  walls  of  the  medullary  canals  and 
spaces.  In  both  these  positions,  indeed,  very 
many  of  them  can  be  seen  by  the  unassisted 

eye;  they  being  more  numerous  in  proportion  as  the  compact  sub- 
stance of  the  bone  is  thicker.  The  larger  passages  are,  however, 
merely  for  the  vascular  branches  communicating  with  the  proper 
capillary  plexus  in  the  interior  of  the  bone-substance.  Kolliker 
has  never  noticed  coecal  terminations  of  these  vascular  canals.  The 
internal  network  must,  however,  in  some  parts  have  little  or  no 
communication  with  vessels  from  the  surface  of  the  bone — as  at  the 
points  of  insertion  of  many  tendons  and  ligaments,  &c. 

It  should  be  added  here  that  Tomes  and  De  Morgan  have  de- 
scribed still  another  kind  of  cavities  in  bone,  which  they  have 
named  Haversian  spaces.  These  are  apparently  formed  by  the  ab- 
sorption of  previously-formed  bone,  between  and  parallel  to  the 
Haversian  canals;  present  rough  parietes,  and  are  sometimes  formed 
at  the  expense  of  portions  of  two  or  three  of  the  Haversian  sys- 
tems or  rods  at  the  same  time.  After  attaining  their  full  diameter, 
ossification  commences  within  them,  and  each  of  them  becomes  a 
new  Haversian  canal,  surrounded  by  its  concentric  laminse,  and  its 
lacunae  and  pores.  These  cavities  are  very  large  and  numerous  in 
newly-formed  bone  situated  near  ossifying  cartilage;  they  are,  how- 
ever, never  absent  in  the  oldest  subject,  and  may  be  accepted  as  a 


326 


THE   TISSUES. 


demonstration  of  the  fact  that  bone  is  constantly  undergoing  an 
active  disassimilation  and  repair.  Indeed,  one  side  of  an  Haversian 
space  niay  be  becoming  the  seat  of  a  new  Haversian  rod  of  bone, 
while  the  opposite  is  undergoing  further  enlargement  from  ab- 
sorption. 

The  contents  of  the  Haversian  canals  are — first^  the  vessels;  se- 
condlij,  the  nerves  of  bone ;  and,  thirdly^  in  case  of  the  larger  canals, 
a  small  quantity  of  marrow  surrounding  the  former. 

Differences  in  the  Compact  and  the  Cancellated  Forms  of  Bone-structure. 

All  bones  contain  both  the  cancellated  and  the  compact  forms  of 
structure ;  the  former  constituting  an  external  layer  of  varying 
thickness,  and  the  latter  the  internal  portions.  In  the  shafts  of  the 
long  bones,  however,  the  entire  thickness  is  formed  of  compact 
bone-substance ;  and  the  same  is  true  of  the  thinnest  portions  of 
some  of  the  flat  bones.  The  extremities  of  the  long  bones,  however, 
like  all  the  short  bones,  consist  of  a  thin  layer  of  compact  substance 
externally,  and  cancellated  substance  within. 

In  both  forms,  however,  the  bone-tissue  is  arranged  in  the  form 
of  laminae  or  plates,  formed  of  granules  or  hyaline  substance  (or 
both),  as  already  described  (p.  321);  and  the  manner  in  which  these 
laminre  are  arranged,  determines  the  two  forms  of  bone-substance 
now  to  be  described. 

1.  Cancellated  Bone-structure. — The  cancellated  bone-structure 
consists  of  an  aggregation  of  cavities,  each  of  which  is  called  a  can- 
Fig.  215. 


spherical  caucclliiK  (diagrammatic).    Its  walls  consist  of  three  lamelU-e,  with  their  lacuuse  and  pores. 


OSSEOUS  TISSUE. 


327 


cellus^  whose  walls  are  formed  of  laminae  of  osseous  tissue.  These 
cavities  are  quite  irregular  in  form,  and  communicate  freely  with 
each  other,  as  may  be  seen  in  a  section  of  the  short  bones,  or  of  the 
extremities  (epiphyses)  of  the  long  ones.  Indeed,  their  appearance 
is  so  similap  to  the  areolas  of  the  sponge,  that  the  terms  spongy^ 
areolar^  or  reticulated  bone-structure  are  also  applied  to  them. 

The  walls  of  the  cancelli  are  formed  of  several  concentric  laminte 
of  osseous  tissue,  between  and  in  the  substance  of  which  lacunae 
and  pores  exist;  and  through  an  opening  the  vessels  are  sent  into 
the  cavity  of  the  cancellus,  to  ramify  upon  its  inner  surface.  If  the 
cancellus  be  supposed,  for  the  sake  of  simplicity,  to  assume  a  sphe- 
rical form,  its  appearance  on  section  will  be  represented  by  Fig.  215. 

Fig.  216. 


Appearance  of  cancelli  while  developing. 
At  A,  the  section  is  made  near  the  surface  of 
ossification  ;  at  B,  more  distant,  and  showing 
the  cancelli  with  thicker  walls.  The  new 
osseous  lining  is  transparent,  and  appears 
light  in  both  figures.  Tho  cancelli  are  filled 
with  debris,  from  grinding  the  preparation. 
A,  in  Fig.  B,  shows  where  a  bony  partition 
has  been  broken  away. 


The  cancelli,  however,  in  foct,  communicate  so  freely  with  each 
other,  that  their  walls  lose  the  structural  regularity  there  represented; 


328  THE   TISSUES. 

and  hence  this  form  of  bone-substance  seems  rather  to  present  an 
interlacement  of  lamellae,  rods,  and  fibres,  very  irregularly  arranged. 
(Fig.  216.)  If  the  connecting  rods  are  of  considerable  size,  they 
contain  vascular  canals ;  otherwise,  merely  laminae,  lacunae,  and 
pores.  The  lacunae  are  disposed  in  every  possible  direction ;  but 
mostly  with  their  long  axes  parallel  to  that  of  the  fibres  and  rods, 
and  with  their  flat  surfaces  directed  towards  the  cancelli,  into  which 
the  most  superficial  lacuna  freely  open.  The  vessels  of  difl'erent 
cancelli  freely  anastomose  with  each  other. 

The  cancelli  contain — -firsts  the  vessels  already  mentioned ;  se- 
condly, a  prolongation  of  the  periosteum  or  endosteum  supporting 
these  vessels ;  and,  thirdly,  more  or  less  fat-cells  with  red  contents 
(marrow).  Nerves  also,  fourthly,  are  distributed  to  the  marrow, 
especially  in  case  of  the  bodies  of  the  vertebrae. 

2.  Compact  Bone-structure. — The  thinnest  layers  of  compact  tissue 
consist  merely  of  parallel  superimposed  lamellae,  between  and  in 
the  substance  of  which  lacunas  and  pores  (but  no  vessels)  exist; 
e.  g.  some  portions  of  the  lachrymal  and  palate-bones.  Indeed,  the 
wall  of  a  cancellus,  as  before  described,  is  essentially  a  very  thin 
layer  of  compact  bone-structure. 

When  the  compact  structure,  however,  attains  to  a  thickness  of 
^'g  of  an  inch,  and  more,  a  different  arrangement  of  the  lamellae  is 
found.  And  in  the  long  bones  the  compact  substance  consists  of 
two  systems  of  lamellae  (the  general  and  the  special),  and  the  inter- 
stitial osseous  tissue,  or  that  between  the  Haversian  rods. 

1.  The  general  (fundamental)  lamellae  are  parallel  to  the  external 
and  the  internal  surface  of  the  bone.  These  alone  exist  where  the 
compact  substance  is  very  thin.  They,  however,  rarely  entirely 
surround  the  long  bones,  and  are  absent  in  the  fast-growing  bones 
of  young  animals.'  {Tomes  and  De  Morgan)  They  are  in  immediate 
connection  at  many  points  with  those  next  to  be  described,  and  are 
seen  in  Fig.  217.  The  lacunas  are  placed  with  their  surfaces  parallel 
with  those  of  the  lamclke ;  their  pores  opening  in  part  on  the  ex- 
ternal and  internal  surfaces  of  the  bone,  and  in  part  communicating 
with  each  other,  though  they  probably  terminate  in  blind  extremi- 
ties at  points  covered  by  the  articular  cartilages.     The  thickness  of 

'  In  these  the  circumferential  laminie  are  replaced  by  a  series  of  undulating 
laminsR,  which,  subse(iuoiitly  extending  outwards,  arch  over  and  inclose  the  nearest 
vessels  of  the  periosteum  ;  and  in  the  spaces  thus  formed,  Haversian  rods  are  de- 
veloped (p.  357). 


OSSEOUS   TISSUE. 
Fig.  217. 


329 


A.  Trausverse  section  of  ulna,  deprived  of  its  earth  by  an  acid.  The  openings  of  the  Haversian 
canals  seen,  natural  size.  A  small  portion  is  shaded,  to  indicate  the  part  magnified  in  B  B.  Part 
of  the  section  A,  magnified  20  diameters.  The  fundamental  or  general  lamellse  are  seen  at  a,  and 
between  the  concentric  lamellaj  the  lacunaj  appear  as  little  dark  specks,     h.  Portion  of  a  cancellus. 

eacli  lamella  averages  j^(j  to  ^-^  of  an  incli  in  the  cranial  bones, 
and  their  number  varies  from  10  to  100.  The  layer  formed  by  them 
varies  between  j?^  and  -g'^  of  an  inch  in  thickness.  It  gives  off  pro- 
cesses, g^^  to  y^o  of  ^11  i^<^^  thick,  between  the  Haversian  rods. 

2.  The  special  lamellas — those  concentrically  surrounding  the  Ha- 
versian canals — constitute,  as  it  were,  the  walls  of  the  latter,  and  are 
intimately  united  to  each  other.  The  number  surrounding  the 
canal,  and  the  consequent  thickness  of  the  system — the  Haversian 
rod — formed  by  them,  bear  no  constant  relation  to  the  size  of  the 
canal;  smaller  canals  being  sometimes  surrounded  by  numerous 
lamella3,  and  larger  ones  by  but  few.  Generally  the  largest  canals, 
and  the  most  minute,  have  but  few  surrounding  lamellas,  and  there- 
fore have  thin  walls;  while  those  of  a  middle  size  have  thick  ones. 
The  thinnest  walls  measure  y^Vtt  to  g-^^y  of  an  inch,  and  the  thickest 


T5<5 


to  j|^  of  an  inch.  {KoUiker.)    Each  lamella  is  from 


to 


2i'(T(y  of  ail  inch  thick,  averaging  from  ^jj^^jj  to  ^j^^jf  of  an  inch. 


830 


THE   TISSUES. 


218. 


They  frequently  present  two  distinct  layers;  the  outer  being  dis- 
tinctly granular,  the  inner  clear  and  transparent.  The  innermost 
lamella  of  an  Haversian  rod  is,  however,  sometimes  transparent 
throughout.  The  number  of  lamellae  in  each  Haversian  rod  is 
usually  from  8  to  15 ;  but  sometimes  there  are  only  4  or  5,  and 
occasionally  as  many  as  18  to  22.  The  whole  Haversian  rod  ave- 
rages about  j^o  of  an  inch  in  diameter. 

Between  and  in  the  substance  of  the  lamella,  the  lacunce  and 
pores  exist.     The  lacunse  have  their  long  diameter  curved  so  as  to 

lie  concentrically  with  the  larnellas  in  a 
transverse  section  of  the  Haversian  rods, 
their  flat  surface  presenting  towards  the 
Haversian  canal.  Their  very  numerous 
pores  produce  a  very  close  striation  ra- 
diating from  the  Haversian  canals,  as 
shown  by  Fig.  218.  The  lacunte  are 
sometimes  very  numerous,  at  others  very 
scanty.  In  the  former  case,  they  are  ge- 
nerally arranged  in  tolerably  regular  al- 
ternation, or  one  behind  another  in  the 
direction  of  the  radius  of  the  Haversian 
rod.  Frequently,  however,  they  are  very 
irregularly  crowded  together,  or  are  se- 
parated by  wider  interspaces. 

All  the  pores  arising  from  the  inner 
aspect  of  the  innermost  lacuna)  penetrate  into  the  Haversian  canals. 
From  the  edges  and  external  aspect  of  the  same  lacuna  other  pores 
are  given  off  which  communicate  with  the  proximate  pores  of  the 
more  distant  lacunee,  and  thus  the  Haversian  rod  is  completely  pe- 
netrated by  the  pores  and  lacunas,  and  permeated  by  the  nutritive 
fluid  contained  in  them.  The  various  forms  of  lacunae  and  pores 
are  shown  by  Fig.  219. 

The  outermost  lamella  is  often  of  somewhat  irregular  outline 
from  its  being  the  first  formed  in  the  pre-formed  irregular  Haver- 
sian space. 

3.  The  interstitial  osseous  tissue  between  the  Haversian  rods, 
when  it  exists  in  small  quantity,  frequently  presents  only  one  to 
three  lacunie  in  a  transverse  section  (Figs.  220  and  217),  both  of  a 
rounded  form  and  quite  irregularly  disposed.  When  more  abund- 
ant, it  is  distinctly  lamellar,  and  the  lacunae  are  more  regularly  dis- 


Transverse  section  of  a  part  of  the 
bone  surrounding  an  Haversian  ca- 
nal ;  showing  the  pores  commencing 
at  the  inner  surface,  a,  anastomo- 
sing and  passing  from  lacuna  to 
lacuna.  —  Magnified  about  300  dia- 
meters. (Tomes.) 


OSSEOUS   TISSUE. 


381 


Fig.  219. 
b 


'<• 


\ 


N^»(rfr  ^*^^"*^ 


Various  forms  of  lacunse  and  their  pores,  a.  Simple  regular  cavities  without  pores,  from  an  ossi- 
fication of  the  pleura.  6.  From  healthy  human  bone.  V.  One  of  the  outer  lacuna;  of  an  Haversian 
system,  with  pores  all  honding  down  towards  the  Haversian  canal,  c.  Other  forms  from  human 
hone,  showing  the  lateral  connecting  pores,  d.  From  the  Boa,  external  lacunje  of  an  Haversian  sys- 
tem with  unusually  large  pores  dipping  towards  the  vascular  surface,  d'.  Cavity  intermediate  be- 
tween a  lacuna  and  a  pore.     c.  Another  variety  from  the  same  reptile.     {Mr.  Tomes.) 

posed,  and  witli  their  sides  parallel  to  those  of  the  lamellae.  The 
pores  of  these  lacunae  communicate  with  each  other,  and.  with  those 
of  the  surrounding  Haversian  rods,  and  thus  their  nutrition  is  pro 

Fig,  220. 


Transverse  section  of  human  clavicle,  showing  the  orifices  of  the  Haversian  cinals,  and  tho  con- 
centric arrangement  of  the  laminie  of  bony  matter  and  of  tho  lacunso  around  thorn  ;  and  tho  iuter- 
etitial  osseous  substance.    (Magnified  S.J  diameters.) 


332  THE   TISSUES. 

vided  for.  In  man,  however,  the  rods  are  so  crowded  that  no  la- 
mellae exist  between  them ;  but  only  the  interstitial  tissue  with  a 
few  lacunge  (and  their  pores),  as  described  in  the  preceding  sen- 
tence. {KolUker.) 

Chemical  Comjyosition  of  Osseous  Tissue. 

It  is  almost  impossible  to  isolate  the  osseous  tissue  completely 
from  the  vessels  and  nerves  distributed  to  it ;  and  hence  there  is 
some  uncertainty  in  regard  to  its  precise  chemical  composition. 

On  removing  the  vessels  and  nerves  from  the  compact  bone- 
structure,  as  far  as  possible,  the  following  results  are  obtained  by 
the  best  chemical  analysis  of  dried  compact  osseous  tissue : — 

Organic  substance  (osteine)      .         .         .     33  ) 
Mineral  constituents         .         .         .         .     67  f 

Phosphate  of  Lime  .         .         .57 

Carbonate  of  Lime  ...       8 

Phosphate  of  Magnesia  ...       1 

Fluoride  of  Calcium  ...       1 

Osseous  tissue  also  contains  the  chloride  of  sodium,  and  some 
alkaline  sulphates  and  fat.  The  last,  amounting  to  from  one  to 
three  per  cent,  in  some  bones,  must  belong,  in  all  probability,  to  the 
blood  in  the  vessels,  or  to  the  marrow  in  the  cavities  of  bone;  while 
Lehmann  believes  the  chloride  of  sodium  (.25  to  .38  per  cent.),  also, 
is  derived  probably  from  the  vessels  or  the  fluid  in  the  lacuna?  and 
pores;  and  the  alkaline  sulphates  are  a  product  of  the  incineration 
of  the  bone. 

The  amount  of  icale)-  in  bone  is  about  13  per  cent.  {Robin  and 
Verdeil.y  The  flat  bones  contain  more  water  than  the  cylindrical; 
probably  because  they  are  more  vascular.  Human  bones  contain 
more  water  than  those  of  any  other  mammal  {Stai-k);  the  bones  of 
birds  still  more ;  and  the  bones  of  fishes  most  of  all  animals.  Nasse 
maintains  that  the  hardness  of  bones  is  not  affected  by  their  pro- 
portion of  water;  a  proposition  which  seems  untenable  in  respect 
to  diseased  bones  at  least. 

The  hone-cartilage,  as  Lehmann  terms  it,  may  be  separated  from 
the  mineral  matters  by  the  prolonged  action  of  dilute  (1  to  7  of 

'  Dr.  Stark  found  only  tliree  to  seven  per  cent. 


OSSEOUS  TISSUE.  333 

■water)  and  frequently  changed  h3^drocliloric  or  nitric  acid  ;  and  thus 
obtained,  it  perfectly  retains  the   form  of  the  bone  of  which  it 
constituted  a  part.     In  its  moist  state, 
it   is   a   tolerably   elastic,   yellowish,  ^^^   ^^^'  ^  ^' 

translucent  substance;  and  in  its  che- 
mical analogies  it  is  found  to  coincide 
perfectly  with  glutin,  except  that  the 
former  has  always  a  little  sulphur 
which  is  absent  in  the  latter.  Under 
the  microscope  it  shows  a  network  of 
obliquely  decussating  fibres,  as  seen 

T~i-         nn-i         mi         i  i.M  •  Thin  layer  peeled  off  a  softened  bone, 

m    Fig.    221.       Ihe    bone-cartilage    is,      as  U  appears  under  a  magnifying  power 

therefore,    actually  osteine,  as    shown    «f  ^oo.   The  figure,  which  is  intended  to 

.  represent  the  reticular  structure  of  the 

on  page  99.       It    is  converted    by  boil-      osteine  of  a  lamella,  gives  a  better  idea  of 

ing;  water  into  three  or  four  times  its    ^^^  "^^^"^  ^^^'^  ^^^^  '«'^"  ^'^'■'^"  "^ 

"  than  usual  from  the  eye. 

volume  of  glutin. 

On  the  other  hand,  the  osteine  may  be  removed  from  the  mineral 
constituents  by  calcination,  or  by  careful  boiling  in  dilute  alkalies. 
In  this  case,  also,  the  mineral  constituents  alone  remaining,  preserve 
the  original  form  of  the  bone. 

It  is  probable  that  the  phosphate  and  carbonate  of  lime  are  united 
together,  before  combining  chemically  with  the  osteine  {Robin  and 
Verdeil);  and  possibly  the  fluoride  of  calcium  and  the  phosphate 
of  magnesia  are  also  previously  combined  with  the  two  first  men- 
tioned salts.  Still,  the  organic  and  mineral  matters  are  by  no 
means  always  in  the  same  proportion  in  the  different  bones  of  the 
same  person.  The  bones  of  the  extremities  contain  more  earthy 
matter  than  those  of  the  trunk ;  and  the  humerus  and  femur  more 
than  the  other  cylindrical  bones.  The  ribs  and  the  clavicles  con- 
tain on  an  average  more  osteine  than  the  vertebrae;  and  the  bones 
of  the  pelvis  approximate  the  latter.  Of  the  different  mineral  mat- 
ters, the  phosphate  of  magnesia  always  rises  and  falls  with  the  phos- 
phate of  lime ;  while  the  ratio  of  the  carbonate  of  lime  to  the  phos- 
phate varies,^  though  within  certain  not  very  wide  limits  at  the  same 
age.  Lehmann  found  the  proportion  of  the  carbonate  to  the  phos- 
phate of  lime  in  the  bones  of  a  new-born  infant  to  be  1 : 3.8;  in  a 
male  adult,  1 :  5.9;  and  in  a  man  63  years  old,  1 :  8.1.  In  disease, 
however,  the  carbonate  of  lime  often  increases  while  the  phosphate 
diminishes;  and  hence  it  has  been  asserted,  incorrectly,  that  the 

'  Von  Bibra  asserts  that  these  two  salts  are  always  in  nearly  the  same  ratio. 


334  THE   TISSUES. 

total  amount  of  the  earthy  matters  in  bone  remains  constantly  the 
same.  The  herbivora  have  more  carbonate  of  lime  in  their  bones 
than  the  carnivora,  and  the  pachydermata  and  cetacea  most  of  all. 

The  bones  of  fishes  contain  the  least  earthy  matter  of  all  (21  to 
57  per  cent.). 

The  varying  amount  of  phosphate  of  lime  in  the  different  bones 
has  already  been  stated  (p.  54).  The  bones  of  birds  contain  more 
of  it  than  those  of  mammals,  it  sometimes  rising  to  84.3  per  cent. 
Carnivorous  birds,  however,  have  but  little  more  than  mammals. 

In  pregnancy,  the  consumption  of  phosphate  of  lime  is  so  great 
in  the  development  of  the  skeleton  of  the  foetus,  that  sometimes 
scarcely  any  traces  of  it  can  be  found  in  the  urine  of  the  mother ; 
and  fractures  now  occurring,  unite  with  extreme  difficulty,  and 
sometimes,  indeed,  not  at  all.  The  softened  condition  of  the  bones 
constituting  rickets  also  most  frequently  occurs  during  dentition, 
while  the  phosphate  of  lime  is  required  for  the  development  of  the 
teeth,  the  latter  not  being  aS'ected  by  this  disease. 

It  is  a  singular  fact  that  the  cranial  bones  exhumed  at  Pompeii 
contained  more  fluoride  of  calcium  than  the  bones  of  the  present 
generation. 

Doubtless  the  food  must  exert  some  influence  on  the  composition 
of  the  bones.  Softening  of  the  bones  occurred  in  chickens  de- 
prived, by  Chossat,  of  the  phosphate  of  lime. 

There  is  no  appreciable  difference  in  composition  of  the  bones 
of  the  male  and  the  female. 

Alumina,  oxide  of  iron,  and  silica,  are  frequently  found  in  fossil 
bones;  their  presence  being  probably  due  to  infiltration. 

In  diseased  bones,  a  great  diversity  of  chemical  composition  is 
found.  The  mineral  substances  are,  however,  almost  always  ab- 
stracted from  the  osseous  tissue  earlier  and  in  larger  quantity 
(  Von  Bihra)  ;  so  that  a  relative  increase  of  the  osteine  is  observed. 
Of  the  earthy  matters,  the  phosphate  of  lime  is  the  first  to  be  re- 
moved, and  the  last  to  be  re-deposited  after  the  cessation  of  dis- 
ease. 

The  osteine  is  very  rarely  affected  in  diseased  bones.  From  some 
cases  of  rachitis,  however,  both  Marchand  and  Lehmann  failed  to 
obtain  any  true  glutin. 

The  carbonate  of  lime  frequently  exceeds  its  normal  amount,  only 
in  osteophyte  and  new  formations  of  bone.  It  appears  usually  to 
diminish  and  afterwards  to  increase,  with  the  phosphate. 

In  jjfimary  sclerosis  (eburuation),  there  is  no  excess  of  earthy  mat- 
ters in  proportion  to  the  osteine ;  but  a  considerable  augmentation 
of  the  carbonate  of  lime  in  proportion  to  the  phosphate. 


OSSEOUS  TISSUE.  386 

In  most  osteophytes  (puerperal  or  otherwise),  there  is  an  excess  of 
osteine  and  carbonate  of  lime  above  the  normal  standard.  Very 
likely,  however,  they  approximate  more  nearly  to  true  bone  in  pro- 
portion to  the  time  since  their  first  formation.  The  analy.ses  of 
exostoses  tend  to  the  same  conclusion. 

In  osteoporos'ls  (dilatation  of  the  cancelli  and  of  the  Haversian 
canals),  the  resorption  of  the  mineral  matters  proceeds  more  rapidly 
than  that  of  the  osteine,  and  the  cavities  formed  are  filled  with  fluid 
fat. 

In  rachitis  there  is  a  relative  deficiency  of  earthy  matters,  with 
an  absolute  excess  of  the  osteine;  the  latter  remainino^  unchano-ed 
m  its  nature.  The  assumption  that  the  carbonate  of  lime  is  in- 
creased in  rachitis  is  incorrect.  Nor  can  rachitis  be  conditional  on 
the  occurrence  of  free  acid  in  the  bones,  though  the  phosphate  of 
lime  is  often  much  diminished. 

In  softening  of  bone  in  the  adult  (osteo-malacia),  the  earthy  con- 
stituents are  more  diminished  than  in  any  bone  disease  yet  men- 
tioned. A  large  portion  also  of  the  osteine  is  destroyed.  The 
brittle  network  of  bony  tissue  remaining,  floats  in  thin,  fluid  fat, 
sometimes  amounting  to  twenty  or  thirty  per  cent.  C.  Schmidt 
proved  the  existence  of  free  lactic  acid  in  the  fluid  of  the  long 
bones.  This  may,  however,  be  the  result  and  not  the  cause  of  the 
breaking  down  of  the  bone  into  fragments — a  chemical  process 
having  occurred  in  the  latter. 

In  caries^  the  earthy  matters  most  rapidly  disappear,  and  the  ca- 
vity formed  is  filled  with  fat. 

Properties  and  Uses  of  the  Osseous  Tissue. 

The  characteristic  properties  of  osseous  tissue  are  its  hardness, 
density,  and  rigidity — due  to  the  earthy  constituents;  and  its  elasti- 
city and  flexibility,  dependent  upon  the  osteine.  It  manifests  no 
vital  properties,  except  so  far  as  to  secure  its  own  nutrition  and 
reparation. 

The  uses  of  the  bones  will  be  specified  after  their  structure  is 
described,  in  the  second  section  of  this  chapter. 

Distribution  of  the  Osseous  Tissue. 
The  osseous  tissue  is  found : — 

i.  In  the  bones,  of  which  the  skeleton  is  composed;  to  which  the 
ossicula  auditus,  and  the  os  hyoides  also  belong. 

2.  In  the  bones  developed  in  the  tendons;  as  the  sesamoid  bones, 
patella,  &c. 

3.  In  the  cementum  of  the  teeth. 

Many  of  the  cartilages  also  ossify  pretty  regularly  as  age  ad- 
vances ;  as  the  costal  cartilages,  and  those  of  the  larynx. 


336  THE   TISSUES. 


Distribution  in  the  Lower  Animals. 

In  the  invertebrata  true  osseous  tissue  is  never  found ;  the  exter- 
nal calcareous  skeleton  taking  its  place. 

In  the  other  vertehrata,  osseous  tissue  is  more  extensively  distri- 
buted than  in  man.  It  exists,  1,  in  the  skin  (of  the  armadillo,  tor- 
toise, lizard,  and  fishes) ;  2,  in  muscles  and  tendons  (the  diaphragma- 
tic bone  of  the  camel,  lama,  and  porcupine,  and  the  ossified  tendons 
of  birds) ;  3,  in  the  eye  (the  sclerotic  ring  of  birds,  chelonians  and 
saurians,  and  the  bony  scales  of  the  sclerotic  of  many  fishes);  4,  in 
the  external  portion  of  the  7iose  (the  proboscis  of  the  pig  and  mole 
and  the  os  pronasale  of  the  sloth);  5,  in  the  tongue  (os  entoghssurn 
of  fishes  and  birds) ;  6,  in  the  air-passages  (the  laryngeal,  tracheal, 
and  bronchial  bones  of  many  birds);  7,  in  the  sexual  organs  (penis- 
bone  of  some  mammalia) ;  8,  and  as  additions  to  the  skeleton  (ossa 
sterno-costalia  of  birds  and  some  mammals). 


SECTION  II. 

* 

STRUCTURE   OF   THE   BONES. 

The  bones  are  usually  divided  into  the  long,^  the  short,  and  the 
flat ;  and  the  largest  bones,  especially  the  long  ones,  have  the  follow- 
ing elements  entering  into  their  structure : — 

1.  Osseous  tissue. 

2.  Bloodvessels. 

3.  Nerves. 

4.  Marrow  (adipose  tissue). 

Besides,  the  external  surface  of  the  bones  is  covered  at  every 
point  by  some  one  of  the  following  structures: — 

1.  Periosteum. 

2.  Articular  cartilages,  and  interarticular  fibro-cartilages. 

3.  Synovial  membranes. 

4.  Insertions  (or  origins),  of  tendons  or  ligaments. 

The  penbsiewm*  has  already  been  described  in  general  (page  279); 
it  being  the  fibrous  membrane  which  invests  the  bone,  and  in  which 
the  vessels  ramify  before  entering  the  substance  of  the  latter.  A 
more  definite  description  of  it  will  be  given  in  the  order  above. 

'  The  long  bones  consist  of  the  shaft   (diaphysis)  and  the  two  extremities  (epi- 
physes) ;  the  structure  of  the  latter  being  like  that  of  the  short  bones. 
'  From  wifi,  around,  and  oarim,  a  bone. 


STRUCTURE   OF   THE   BONES.  337 

1.  The  Tme  Osseous  Tissue. 

This  peculiar  element  of  the  bones  has  been  described  at  length 
(pages  321—335). 

2,  The  Bloodvessels  of  the  Bones. 

The  bloodvessels  of  the  bones  are  first  sent  to  the  periosteum, 
which,  besides  the  branches  it  transmits  directly  into  the  substance 
of  the  bone,  presents  a  pretty  close  network  of  capillaries,  2 50^  of 
an  inch  in  diameter  in  its  outer  layer.  The  vessels  entering  the 
substance  of  the  bone  are  very  numerous. 

On  the  long  bones  are  distinct  vessels  for  the  nutrition  of  (1)  the 
cancellated  structure  of  the  extremities,  (2)  of  the  compact  sub- 
stance of  the  shaft,  and  (3)  of  the  marrow.  The  latter,  called  the 
vasa  nutritia,  enter-  the  medullary  cavity  of  the  bones,  one  or  two 
to  the  shaft,  and  several  to  the  epiphyses,  through  large  openings 
and  canals ;  and,  except  a  few  twigs  given  off  to  the  innermost  Ha- 
versian canals  of  the  compact  substance,  ramify  in  the  marrow, 
where  they  form  a  capillary  plexus  whose  vessels  are  from  3  oV  0  to 
asVtr  of  ^^  iiioh  in  diameter. 

(2.)  The  vessels  of  the  compact  substance  rise  principally  from 
those  of  the  periosteum.  They  very  soon  lose  their  muscular  coat, 
and  form  in  the  Haversian  canals  (which  they  fill  either  alone  or 
in  connection  with  some  medullary  substance),  a  network  of  wide 
vessels.  The  latter  can  hardly  be  regarded  as  capillaries,  how- 
ever, since  they  show  a  layer  of  areolar  tissue  and  an  epithelium ; 
and  fine  capillaries  co-exist  with  the  main  vessel  only  in  the  larger 
canals. 

(3.)  The  cancellated  structure  of  the  extremities  of  the  long 
bones  is  supplied  by  the  vessels  transmitted  by  the  numerous  canals 
seen  by  the  unaided  eye  upon  their  external  surface. 

The  venous  blood  is  returned  from  all  the  long  bones  in  three 
ways :  (1),  by  a  large  vein  accompanying  the  nutrient  artery,  and 
whose  ramifications  it  follows;  (2),  by  numerous  large  and  small 
veins  at  the  articular  extremities;  and,  (3),  by  many  small  veins  in- 
dependent of  each  other  in  the  compact  tissue  of  the  shaft,  in  which 
their  roots  occupy  the  wider  spaces  and  sinuses,  or  pouch-like  ex- 
cavations, which  are  very  evident  in  sections  of  bone.  (Fig.  214:,  3.) 

All  the  vessels  of  bone  just  mentioned  freely  communicate,  so 
19, 


338  THE  TISSUES. 

tliat  it  is  possible  for  the  blood  of  any  one  part  to  reach  any  other 
part. 

In  the  short  bones,  the  bloodvessels  present  very  nearly  the  same 
conditions  as  those  of  the  epiphyses  of  the  long  bones ;  the  arteries 
and  veins  of  larger  and  smaller  size  entering  and  quitting  the  bone 
at  numerous  points  on  the  surface. 

In  the^^a;!  bones,  as  the  scapula  and  coxal  bone,  there  are  distinct 
apertures  for  the  larger  arteries  and  veins ;  the  compact  substance 
receiving  finer  vessels  from  the  periosteum,  and  the  cancellated 
structure  being  supplied  by  numerous  and  large  vessels.  In  the 
flat  cranial  bones  the  arteries  mostly  enter  the  compact  and  the 
spongy  portions  (diploe)  from  both  surfaces;  while  the  veins  have 
only  their  extremities  free  in  the  cavities  of  the  diploe  as  in  other 
bones,  and  their  trunks  contained  in  large,  arborescent  canals, 
emerge  at  definite  points  through  large  apertures  (emissaria  Santo- 
rini),  and  communicate  freely  with  the  veins  of  the  dura  mater. 
The  veins  of  the  cranial  bones,  however,  become  obliterated  as  age 
advances,  coincidently  with  the  diminution  of  the  diploe.  In  the 
new-born  infant,  arteries  as  well  as  veins,  occupy  the  emissaria. 
The  articular  cartilages  have  no  vessels  at  all.  Those  of  the  syno- 
vial membranes  will  be  described  further  on. 

Lymphatic  vessels  in  hone  have  been  described  by  some  anatomists. 
Kcilliker,  however,  does  not  admit  their  existence  in  either  bone, 
periosteum,  or  synovial  membranes;  though  they  pretty  certainly 
exist  in  the  loose  areolar  tissue  around  the  last,  especially  at  the 
knee. 

3.  Nerves  of  the  Bones. 

It  is  necessary  to  distinguish  the  nerves  of  the  bones  from  those 
of  the  periosteum,  in  which  the  former  lie,  before  entering  the  sub- 
stance of  the  bone.  The  nerves  of  the  bone  are  larger  than  those 
of  the  periosteum,  and  sometimes  give  off  the  latter  as  branches. 
They  exist  in  all  bones — except,  perhaps,  the  small  bones  of  the  ear, 
and  the  sesamoid  bones — though  not  in  all  bones  fulfilling  the  same 
conditions.  In  the  large  cylindrical  bones,  ihcy^  first,  penetrate  into 
the  medullary  cavity  with  the  nutrient  vessels  of  the  marrow  (whe- 
ther there  be  cne  or  two);  the  trunks  being  visible  to  the  naked 
eye,  and  as  much  as  -j'j  of  an  inch  in  diameter.  They  are  distri- 
buted to  the  marrow,  following  the  course  of  the  vessels,  though 
not  always  in  apposition  with  them,  towards  the  epiphyses;  forming 


STRUCTURE    OF   THE    BOXES.  339 

many  ramifications,  and  but  few  anastomoses,  Secondly^  numerous 
finer  nerves  penetrate  with  the  numerous  bloodvessels  into  the  can- 
cellated tissue,  and  ramify  in  the  medulla.  And,  thirdly^  extremely 
delicate  nervous  filaments  are  sent  into  the  compact  structure  of  the 
epiphyses,  in  company  with  the  minute  arteries  by  which  they  are 
penetrated.  The  smaller  cylindrical  bones  of  the  hand  and  foot 
present  the  same  conditions  as  the  larger  ones  just  described,  except 
that  the  nerves  are  not  so  regularly  divided  into  epiphysal  and  dia- 
physal,  on  account  of  the  undeveloped  condition  of  the  medullary 
cavities. 

Of  the  short  bones,  the  vertebra  are  most  abundantly  supplied 
with  nerves ;  and  especially  their  bodies.  {Kolliker.)  They  enter 
anteriorly,  posteriorly,  and  on  the  sides,  in  company  with  the  ves- 
sels, and  are  distributed  to  the  marrow  of  the  spongy  substance. 

In  the  flat  bones — as  the  scapulae  and  coxal  bones — the  nerves 
are  very  numerous,  and  enter  the  bone  with  the  larger  vessels  before 
described.  In  the  occipital,  parietal,  and  frontal  bones,  microscopic 
nervous  filaments  enter  as  far  as  to  the  diploe,  upon  the  finer  arteries. 

The  nerve-fibres  thus  richly  distributed  to  bone  are  both  cerebro- 
spinal and  sympathetic ;  the  former  constituting  about  two-thirds 
of  all  the  fibres,  and  being  goVo  to  30V0  of  an  inch  in  diameter, 
{Kolliker.)  The  periosteal  nerves  are  also,  apparently,  mainly  spinal; 
though  some  participation  of  the  sympathetic  cannot,  perhaps,  be 
denied  in  their  case,  also. 

How  the  nerves  of  bone  terminate,  is  not  yet  decided.  They 
sometimes  have  Pacinian  bodies  upon  them  just  before  entering  the 
bone-substance. 

The  principal /wndzbn  of  the  nerves  of  bone  seems  to  be  to  regu- 
late the  flow  of  blood  and  plasma  through  the  part.  {Kolliker.) 

The  synovial  membranes  also  contain  nerves.  The  ligaments  (in 
man)  do  not;  and  the  same  is  true  of  the  articular  cartilages. 

4.  The  Marrow  of  the  Bones  {Medulla). 
Almost  all  the  larger  cavities  in  the  bones  are  filled  by  a  soft^ 
transparent,  yellowish  or  reddish,  highly  vascular  substance,  the 
marrow.  It  is  found  chiefly  in  the  medullary  canals  of  cylindrical 
bones,  and  in  the  cancelli  of  all  bones ;  though  it  also  enters  into 
the  larger  Haversian  canals  of  the  compact  substance.  In  the  shafts 
of  the  long  bones  it  appears  as  a  yellow  semi-fluid  substance,  difter- 
ing  essentially  in  chemical  composition  from  the  red  kind  of  marrow 


340  THE   TISSUES. 

which  occurs  in  their  epiphyses,  and  in  the  short  and  flat  bones,  the 
sternum,  and  the  bodies  of  the  vertebrae.  These  two  forms  are  also 
quite  different  in  chemical  composition.  While  the  former  is  made 
up  (in  the  bones  of  the  ox,  according  to  Berzelius)  of  96  per  cent, 
of  fat,  1  of  areolar  tissue,  and  '6  of  fluid  with  extractive  matter,  the 
latter  (in  the  diploe)  contains  75  per  cent,  of  water,  the  rest  (25  per 
cent.)  being  made  up  of  solid  matters,  albumen,  fibrine,  and  ex- 
tractive matter,  similar  to  those  of  muscle,  with  merely  traces  of  f;xt. 
In  its  structure^  marrow  presents,  besides  vessels  and  nerves,  areo- 
lar tissue,  fat-cells,  free  fat,  and  a  yellowish  fluid  ;  and,  lastly,  pecu- 
liar minute  cells — marrow-cells. 

1.  The  areolar  tissue  inclosing  the  marrow  of  the  shaft  of  long 
bones  is  of  a  firm  consistency,  but  is  improperly  described  as  an 
endosteum  (internal  periosteum),  since  it  cannot  be  separated  as  a 
distinct  structure.  It  also  penetrates  the  marrow  of  the  long  bones, 
and  supports  the  vessels  and  nerves ;  while  it  does  not  enter  at  all 
into  the  marrow  of  the  cancelli,  except  in  case  of  the  larger  masses 
of  it. 

2.  Fat-cells,  ^^j^  to  ^\^  of  an  inch  in  diameter,  and  often  with  a 
distinct  nucleus,  occur  in  both  forms  of  marrow;  more  abundantly, 
however,  in  the  yellow,  dense  form,  and  generally  not  aggregated 
into  lobules.  In  the  red  variety  they  are  far  less  numerous,  and 
often  isolated  even;  and  hence  the  small  quantity  of  fat  in  the 
diploe.  {BerzeUus.)  lu  dropsical  marrow,  these  cells  are  frequently 
only  half  filled  with  fat,  or  with  but  one  or  more  globules ;  con- 
taining, besides,  a  large  quantity  of  serum  (p.  307).  In  hypersemia 
of  the  bones,  they  are  sometimes  diminished  in  size,  and  are  also 
elongated  and  fusiform. 

3.  Free  fat-glohules,  and  a  clear  or  yellowish  fluid,  are  often  met 
with  in  the  softer  kinds  of  marrow.  The  former  may  possibly  have 
been  derived  from  cells  which  no  longer  exist. 

Lastly,  the  marrow-cells  occur  in  the  red  or  the  reddish  marrow, 
but  never  in  the  yellow.  They  exist  normally  in  the  vertebra},  the 
cranial  bones,  the  sternum,  and  the  ribs ;  and  in  the  upper  maxil- 
lary bone,  also,  where  they  have  been  mistaken  for  cancer-cells. 
They  also  occur  in  the  hypcra3miated  red  marrow  of  the  articular 
extremities  of  the  cylindrical  bones;  but  are  normally  absent  in  all 
the  bones  of  the  extremities,  and  in  the  scapulae  and  the  coxal  bones. 
They  precisely  resemble  the  cells  of  the  young  medulla  (p.  355). 
l/se  of  the  Marrow. — The  cavities  of  the  bonps  in  man  must  be 


THE   PERIOSTEUM.  341 

filled  either  with  a  fluid  or  a  solid  substance,  since  tliey  do  not  com- 
municate with  the  air.  The  marrow  being  a  form  of  adipose  tissue, 
answers  the  purpose,  therefore — first^  of  mere  package ;  but,  secondly^ 
it  also,  from  the  fat  it  contains  being  lighter  than  other  animal  fluids, 
renders  th.e  bones  lighter  than  they  would  be,  were  the  latter  sub- 
stituted; and,  thirdly^  in  the  emergency  of  starvation,  it  is  reab- 
sorbed into  the  blood,  and  thus  prolongs  life — its  cells  becoming 
at  the  same  time  filled  with  a  serous  fluid  (p.  307). 

In  most  birds,  the  cavities  of  the  long  bones  communicate  indi- 
rectly with  the  atmosphere,  and  therefore  contain  no  marrow. 

The  Periosteum. 

The  periosteum  is  a  more  or  less  transparent,  slightly  glistening, 
or  whitish-yellow  extensible  membrane.  It  is  also  vascular,  and 
invests  the  surface  of  the  bones,  except  where  certain  muscles  and 
ligaments  are  inserted,  and  where  the  surface  is  covered  by  the 
articular  cartilages. 

It  is,  however,  not  everywhere  constituted  alike.  When  only 
covered  by  the  skin,  or  connected  with  fibrous  structures  (as  liga- 
ments, tendons,  fasciae,  and  the  dura  mater),  it  is  opaque,  thick,  and 
generally  glistening  like  tendinous  structures.  On  the  other  hand, 
it  is  thin  and  transparent  when  muscular  fibres  rise  directly  from 
it,  and  when  the  muscles  nearly  rest  upon  the  bone  (as  on  the  ex- 
ternal surface  of  the  cranium);  also  in  the  vertebral  canal  and  in 
the  orbit.  When  mucous  membrane  rests  on  bone,  the  periosteum 
is  generally  very  intimately  united  to  it  by  the  submucous  areolar 
tissue ;  so  that  the  two  cannot  be  separated,  and  constitute  a  single 
membrane  of  varying  thickness  (in  the  ethmoid  cells,  maxillary 
sinus,  &c.). 

The  connection  of  the  periosteum  with  the  bone  is  sometimes 
very  loose,  it  being  merely  in  apposition,  or  attached  by  delicate 
vessels  penetrating  the  bone;  and  sometimes  very  firm  and  intimate 
by  means  of  larger  vessels  and  nerves,  and  numerous  tendinous 
filaments.  The  former  occurs  more  generally  wdiere  the  periosteum 
is  thin,  and  the  osseous  tissue  more  compact,  as  in  the  shafts  of  long 
bones  and  in  the  sinuses  of  the  cranium ;  the  latter,  where  the  peri- 
osteum is  thicker,  and  the  compact  substance  thinner,  as  in  the  epi- 
physes, in  the  short  bones,  the  palate,  and  at  the  base  of  the  cranium. 

In  its  intimate  structure,  the  periosteum  presents  almost  always, 
except  where  muscles  rise  from    it  directly,  two  layers,  differing 


342  THE   TISSUES. 

more  or  less  in  structure,  though  closely  connected.  The  external 
layer  is  composed  chiefly  of  white  fibrous  tissue,  with  occasional 
fat-cells,  and  in  this  are  the  true  vessels  and  nerves  of  the  peri- 
osteum. The  inner  layer  contains  elastic  fibres,  usually  of  the  finer 
sort,  constituting  very  thick  networks — true  elastic  membranes — 
superimposed  one  upon  another.  The  white  fibrous  tissue  consti- 
tutes the  least  important  elenient.  Nerves  and  vessels  occur  in  this 
layer,  also;  but  they  merely  pass  through  it,  preparatory  to  entering 
the  bone  itself. 

The  following  surfaces  of  the  bones  are  not  covered  by  peri- 
osteum : — 

1.  All  surfaces  where  the  bone  is  covered  by  the  articular  (or 
other)  cartilage,  or  fibro-cartilage. 

2.  Where  ligaments  and  tendons  are  attached  to  bones  at  a  cer- 
tain angle ;  e.  g.  the  ligamenta  subflava,  ligamentum  teres,  liga- 
mentum  patellae,  and  the  intervertebral,  ilio-sacral,  and  interosseous 
ligaments;  and  the  tendons  of  the  deltoid,  the  coraco-brachialis, 
popliteus,  triceps,  psoas-iliac,  gastrocnemii,  quadriceps  fcmoris,  glu- 
taei,  ko,.  On  all  these  surfaces  the  structures  just  mentioned  are 
attached  directly  to  the  bone,  and  not  a  trace  of  periosteum  is  found. 

Articular  Cartilages. 

The  articular  cartilages  cover  the  bones  at  their  articular  extre- 
mities. They  are  closely  applied  to  the  bone  with  a  rough,  hol- 
lowed, or  raised  surface,  but  are  not  united  to  it  by  any  intermediate 
substance.  On  its  free  surface,  it  is  in  most  joints  quite  hare  in  the 
adult;  but  covered  in  the  foetus  by  a  delicate  epithelium  like  that 
lining  the  vessels,  as  has  been  already  asserted  (p.  818).  The^iiro- 
cartilages  of  circumference^  so  called  (glenoid  and  cotyloid  ligaments, 
&c.),  are  firm,  yellowish-white  rings  of  white  fibrous  tissue,  con- 
taining a  few  isolated  cartilage-cells,  attached  at  the  border  of  the 
articular  cartilage,  by  a  wider  base,  immediately  to  the  bone,  or 
partly  also  to  the  cartilage.  They  are  generally  free,  and  not  co- 
vered by  the  synovial  membrane  or  any  epithelium.  Reichert 
found  fine  desquamated  flakes  of  cartilage  in  the  synovia,  which 
fell  readily  into  folds,  and  thus  resembled  a  fibro-cartilaginous  tissue. 

In  its  ////ma;:?  structure,  articular  cartilage  is  peculiar  only  in  the 
fact  that  the  cartilage-cavities  near  the  free  surface  are  small,  nu- 
merous, flattened,  and  parallel  to  it;  while  those  in  the  deeper  por- 
tions next  to  the  bone  are  elongated,  and  arranged  perpendicularly 


AETICULAR  CARTILAGES. 


343 


to  tbe  surface  of  the  latter.  (Fig.  222.)  Neither  the  articular  carti- 
lages nor  the  fibro-cartilages  of  circumference  contain  either  nerves 
or  vessels,  though  the  vessels  of  the  synovial  membranes  sometimes 
intrude  upon  them  at  their  borders. 

Dr.  Lcidy,  of  Philadelphia,  has  also  Fig.  222. 

observed  numerous  minute  lacunae  in       

articular  cartila":es.   These  are  lenticu-       ^^  "■ 


lar  in  outline,  y^^^ 


to  ^j'sxj  of  an  inch 


in  length,  and  most  abundant  in  the 
deepest  layer  of  the  cartilage,  and  de- 
crease in  number  towards  its  free  sur- 
face. Another  peculiarity,  also  de- 
scribed by  Dr,  Leidy,  is  the  penetra- 
tion of  the  structure  of  the  articular 
cartilage  by  fibres  or  columns  of  bone. 
These  fibres  are  compressed  and  cylin- 
drical in  shape,  and  present  an  ellip- 
tical outline  on  a  transverse  section. 
They  are  not  numerous,  are  concen- 
trically laminated,  and  present  a  radi- 
ated appearance,  not  very  unlike  an 
Haversian  rod;  but  neither  the  Haver- 
sian canal,  nor  the  lacunee  and  pores, 
are  to  be  seen. 

The  condition  of  the  bone  beneath 
the  articular  cartilages  is  peculiar,  con- 
sisting, in  almost  all  joints,  of  a  layer 
of  incompletely  formed  osseous  tissue. 

This  layer  is  g^^  to  ^^^  (average  y^o)  carpal  bone,  cut  perpendicularly,  o.  Most 
n  •       1      ,1  •    1  1    '•  n         •    1         superficial,    flattened   cartilage-cells,     b. 

Ot    an    mch    thick,  and    is    a    yellowish,      Middle  round  cells.     c.  innermost  cells, 

disposed  perpendicularly  in  small  rows. 
d.  Outermost  layer  of  the  bone,  with  os- 
sified fibrous  matrix,  and  thick-walled 
cartilago-ceys,  in  this  instance  appearing 
dark  from  their  containing  air.  e.  True 
bone-substance.  /.  End  of  the  cancelli 
of  the  epiphyses,  g.  One  of  the  cancelli. 
— Magnified  90  diameters.   (Ki'lliker.) 


Articular  cartilage  of  a  human  meta- 


mostly  fibrous,  hard,  and  truly  ossified 
matrix;  containing,  however,  not  a 
trace  of  Haversian  canals  or  medul- 
lary cavities,  nor  any  perfectly  formed 
lacunas.  Instead,  however,  of  these, 
are  found  roundish  or  elongated  cor- 
puscles, aggregated  into  little  masses  or  rows  ,yJ^fy  to  -g 


of  an  inch 


long,  and  j  gVo  to  goiyu  of  an  inch  broad.  These  give  thin  sections 
of  the  bone  a  perfectly  opaque  aspect;  and  are  really  thick- walled 
cartilage-cells,  retaining  their  contents  (fat  and  nuclei),  occasionally 


344 


THE    TISSUES, 


presenting  indications  of  pores,  and  being  perhaps  also  partly  calci- 
fied. In  other  cases  they  are,  in  fact,  undeveloped  lacunae.  This 
layer  is  bounded  towards  the  cartilage  by  a  straight  line,  and  towards 
the  bone  by  a  sinuous  contour.  It  occurs  in  every  articulation, 
except  that  of  the  lower  jaw,  and  those  on  the  os  hyoides.  {Kollik&r?) 
(Fig.  222.) 

In  pathological  states,  the  articular  cartilages  sometimes  assume  a 
fibrous  structure,  a  change  often  attended  by  an  increase  of  thick- 
ness. These  fibres  are  sometimes  half  an  inch  in  length.  [Gruveilhier.) 
Sometimes  they  wear  away  rapidly,  or  even  entirely  disappear,  leav- 
ing the  bones  bare.  They  may  also  be  attacked  by  ulceration ;  this 
penetrating  to  the  bone,  or  commencing  next  to  it  and  extending 
towards  the  free  surface. 

The  Synovial  Memhranes. 
The  synovial  membranes  are  not  closed  cavities,  as  generally  de- 
scribed; but  merely  of  the  form  of  rings,  or  short  tubes,  whose  two 
open  ends  or  borders  are  attached  to  the  circumference  of  the  articu- 
lar surfaces  of  the  bones,  and  thus  connect  them  together.  They 
are  delicate  transparent  membranes,  but  are  often  invested  exter- 
nally by  the  capsular  or  other  ligaments  of  joints,  from  which  they 
are  with  difficulty  separated. 

The  precise  relations  of  the  synovial  mem- 
branes are  as  follows:  They  are  attached 
simply  to  the  border  of  the  articular  surfiice, 
and  either  thrown  across  directly  to  the  other 
bone,  or  they  may  in  the  first  place  invest  a 
small  surface  of  the  first  bone  also,  as  well 
as  the  cartilage,  and  then  pass  to  the  other 
bone.  (Fig.  223.)  In  either  case,  the  syno- 
vial membrane  does  not  adhere  directly  to 
the  hard  tissues  underneath  it ;  but  is  more 
or  less  closely  connected  with  the  periosteum 
or  the  perichondrium.  It  finally  terminates, 
without  any  distinct  margin,  near  the  border 
of  the  articular  cartilage,  being  inseparably 
united  with  its  perichondrium. 

In  their  intimate  structure,  the  synovial 
membranes  consist — firsts  of  a  layer  of  con- 
densed areolar  tissue,  with  vessels  and 
nerves;  and,  secondbj^  an  epithelium. 


Fig.  223. 


Diagram  of  a  longitudinal  sec- 
tion of  a  phalangeal  articula- 
tion ;  partly  after  Arnold.  a. 
Bones,     b.   Articular  cartilage. 

c.  PorioNtoum  continuous  with 
the  pericliondrium  of  the  latter. 

d.  Synovial  membrane  at  the 
edge  of  the  cartilage,  connected 
at  (Irst  witli  the  poriclioiidrlum. 

e.  Its  epithelium.  {K  Uih'.r.) 


SYNOVIAL   MEMBRANES.  346 

1.  The  coriura  (or  layer  of  areolar  tissue)  sometimes,  though 
rarely,  contains  fat-cells  in  its  meshes,  and  a  few  scattered  cartilage- 
cells  with  thick,  opaque  walls. 

2.  The  epilhelium  is  composed  of  from  one  to  four  layers  of  large 
tessellated  cells,  24'jj^  to  j-^^-q  of  an  inch  in  diameter,  with  roundish 
nuclei  of  g-^'g^  to  4xj'g^  of  an  inch. 

The  synovial  membranes  present  large  adipose  masses  and  vascu- 
lar processes.  The  former,  once  erroneously  termed  Haversian 
glands,  are  found  principally  in  the  hip-  and  knee-joints,  and  consist 
of  collections  of  fat-cells  in  vascular  portions  of  the  synovial  mem- 
brane. The  vascular  processes  constitute  red,  flattened  projections 
of  the  synovial  membrane,  with  an  indented  and  polished  margin, 
furnished  with  minute  processes.  The  folds  are  usually  placed 
close  to  the  junction  of  the  synovial  membrane  with  the  articular 
cartilage,  and  lie  flat  upon  the  latter,  forming  a  sort  of  coronal 
around  it.  They  differ  from  the  rest  of  the  membrane  in  structure, 
principally  in  their  great  vascularity,  since  they  consist  of  little 
else  than  minute  arteries  and  veins,  and  delicate  capillaries  forming 
wavy  loops  at  the  edge  of  the  processes ;  and  hence  resemble  the 
choroid  plexus  in  the  ventricles  of  the  brain.  Besides  the  vessels, 
these  processes  consist  of  areolar  tissue  and  the  epithelium  found 
elsewhere  on  these  membranes.  At  the  edge  of  these  processes, 
projections  of  the  membrane,  of  extraordinary  forms  (sometimes 
resembling  the  stems  of  a  cactus),  are  found.  It  is  these  non- 
vascular processes  which,  being  enlarged  and  then  detached,  con- 
stitute one  of  the  forms  of  the  erroneously  so-called  loose  cartilages 
in  joints,  as  has  already  been  shown  (p.  319,  2). 

The  nerves  of  the  synovial  membrane  are  but  few  in  number. 

The  synovia  is  evidently  secreted  by  the  epithelial  cells  upon  the 
vascular  processes ;  and  to  a  very  slight  extent  also,  doubtless,  by 
those  on  the  rest  of  the  membrane.  The  properties  of  this  fluid 
have  already  been  stated  (pp.  180  and  198).  Its  function  is  to 
diminish  friction  in  the  varied  movements  of  the  joints. 

Inter- Articular  Fihro-  Cartilages. 
The  inter-articular  fibro-cartilages  may  be  mentioned  here,  though 
they  do  not  actually  come  into  contact  with  the  bones.  They  are 
interposed  between  the  two  articular-cartilages  of  some  joints  (arti- 
culations of  lower  jaw,  sternum  and  clavicle,  &;c.);  or  form  mere 
projections  between  them  (semilunar  cartilages,  so  called,  of  the 


346  THE   TISSUES. 

knee-joint).  In  intimate  structure  they  do  not  differ  from  other 
fibro- cartilages ;  except  that  the  cartilage-cells  are  smaller  and  more 
abundant  in  the  deep,  and  less  so  in  the  superficial  portions  (p. 
314).  In  old  persons,  they  lose  their  distinct  fibrous  structure,  and 
assume  a  yellow  or  brownish  color. 

The  inter-articular  ligaments,  so  called,  must  also  be  classified 
with  the  preceding  fibro-cartilages.  They  are  not  covered  by  sy- 
novial membrane;  nor  even  by  an  epithelium,  except  for  a  small 
extent  at  their  attached  borders  (e.  g.  ligamentum  teres,  &c.). 

Connection  of  Tendons  and  Ligaments  with  the  Bones. 
Tendons  and  ligaments  are  generally  inserted  into  the  periosteum. 
Both  are,  however,  in  some  instances  inserted  into  the  bone  itself; 
there  being  no  trace  of  periosteum  intervening.  This  is  the  case 
with  the  tendons  of  the  quadriceps  femoris,  pectoralis  major,  del- 
toid, latissimus  dorsi,  psoas-iliac,  glutsei,  the  tendo-Achillis,  &c.,  and 
the  ligaments,  mentioned  on  page  342,  2.  In  these  cases  the  fasciculi 
of  the  tendon  rest  at  an  acute  or  a  right  angle  on  the  surface  of  the 
bone,  and  become  attached  to  all  the  elevations  and  depressions  of 
its  surface.  Close  to  the  bones,  the  tendons  frequently  also  con- 
tain delicate  cartilage-cells.  They  also,  in  exceptional  cases,  be- 
come entirely  incrusted  with  calcareous  salts  in  the  form  of  granules, 
next  the  bone.     Fig.  224  shows  the  peculiarities  just  mentioned. 


The  general  structure  of  the  proper  joints  or  movable  articula- 
tions (diarthroses)  may  be  gathered  from  what  has  preceded.  Each 
diarthrodial  articulation  contains  the  following  elements: — 

1.  The  articular  cartilages,  covering  the  extremities  of  the  bones, 
described  on  page  343. 

2.  The  synovial  membrane,  secreting  the  synovial  fluid  (p.  344). 

3.  In  some  instances,  inter-articular  fibro-cartilages  (p.  345). 

4.  Ligaments  of  various  forms ;  inter-articular  and  circumferen- 
tial (pp.  346  and  342). 

The  amphiarthroses,  or  symphyses,  have  a  simpler  structure.  Here 
the  connection  of  the  bones  is  by  cartilage  alone,  or  associated  with 
fibro-cartilage  and  white  fibrous  tissue.  In  the  symphysis  pubis, 
sacro-iliac  synchondrosis,  and  the  articulations  of  the  bodies  of  the 
vertebrae,  the  surfaces  of  the  bones  are  directly  covered  by  a  layer 
of  true  cartilage;  and  which  in  the  first  two  situations,  is  directly 
connected  with  the  o})posite  layer,  and  in  the  last,  by  means  of  fibro- 
cartilage  and  white  fibrous  tissue  in  consecutive  layers.     In  the 


PROPERTIES   OF   THE   BONES. 


347 


first  two  cases  also,  there  is  frequently  a  cavity  in  the  interior  of 
the  connecting  substance;  so  that  the  sacro-iliac  symphysis  in  par- 


Fig.  224. 


Insertion  of  the  tendo-Achillis  into  the  calcaneum  of  a  man  sixty  years  old.  A.  Bone  with  lacnnae, 
a;  cancelli  and  fat-cells,  b.  B.  Tendon  ;  with  tendinous  fibres  and  cartilage-cells,  c. — Magnified  300 
diameters.     {Kolliker.) 

ticular  may  be  regarded  as  a  sort  of  movable  articulation.  [Zaglas) 
Some  of  the  articulations  of  this  class  are  also  surrounded  by  liga- 
ments, described  in  all  anatomical  works. 

In  the  synarthroses,  the  bones  are  united  merely  by  an  extremely 
thin  membranous  whitish  streak,  incorrectly  termed  the  sutural 
cartilage.  It  is  really  w];iite  fibrous  tissue,  and  it  gradually  disap- 
pears in  old  age,  and  is  at  last  in  man}'-  parts  entirely  removed, 
especially  on  the  inner  part  of  the  sutures ;  and  even  before  the 
complete  obliteration  of  the  latter.  It  is  properly  termed  the  sutural 
ligament,  therefore. 

Properties  of  the  Bones. 
The  properties  of  the  bones  are  those  of  the  osseous  tissue, 
already  specified  (p.  335),  the  most  important  being  their  rigidity 


34:8  THE   TISSUES. 

and  density,  and  others  incidental  to  these.  Upon  these  proper- 
ties their  uses  depend. 

The  cohesive  force  of  bone  is  truly  astonishing ;  it  being  twice  as 
great  as  that  of  oak,  though  its  specific  gravity  is  to  that  of  oak  as 
92:65.' 

The  vertical  strength  of  bone,  or  its  power  as  a  column  of  sup- 
port, and  to  resist  pressure,  is  still  more  wonderful.  Prof.  Robin- 
son found  that  a  disk  of  bone  one  inch  square,  supported  a  weight 
of  5000*  lbs.  He  does  not,  however,  specify  the  thickness  of  the 
disk. 

The  power  of  the  bones  to  resist  flexion  and  fracture,  or  as  mere 
levers^  must  also  be  mentioned  here.  Prof.  Robinson  found  bone  re- 
lated, in  this  respect,  to  freestone,  lead,  and  several  of  the  strongest 
kinds  of  wood,  as  follows : — 


Fine  freestone     . 

.     1. 

Lead 

.     6.5 

Elm  and  ash 

.    8.5 

Box,  yew,  and  oak 

.    11. 

Bone           .... 

.     22. 

In  other  terms,  bone  is  22  times  as  strong  in  this  respect  as  fine 
freestone;  about  3|  times  as  strong  as  lead;  nearly  2f  times  as 
strong  as  elm  and  ash,  and  twice  as  strong  as  box,  yew,  and  oak. 

Uses  of  the  Bones. 

The  bones  in  their  aggregate  constitute  the  osseous  skeleton  of 
the  vertebrate  animals,^ 

1.  The  skeleton  gives  firmness  to  the  body  and  preserves  its  sym- 
metry. The  spinal  column  and  the  cranium  at  the  same  time  also 
protect  the  spinal  cord  and  the  encephalon;  and  the  bony  walls  of 
the  thorax  and  pelvis,  the  contents  of  these  cavities  respectively. 
All  the  bones,  moreover,  aftbrd  fixed  points  for  the  attachment  of 
the  muscles. 

2.  The  long  bones  are  acted  upon  by  the  muscles  as  levers,  and 
hence  are  the  passive  organs  of  the  motions;  those  of  the  lower 
extremities  being  subservient  to  locomotion,  and  those  of  the  upper, 

'  London  Lancet,  April,  1846,  p.  346.  «  Ibid.,  p.  240. 

'  At  the  age  of  21  years,  the  weight  of  the  skeleton  is  to  that  of  the  whole  body 
(the  latter  being  125  to  130  lbs.) — as  10.5  :  100  in  man,  and  as  8.5  :  100  in  woman. 


USES   OF   THE   BONES.  349 

to  the  infinity  of  movements  of  which  the  latter  are  capable.     The 
ribs  are  thus  subservient  to  the  movements  of  respiration, 

3.  The  long  bones  especially  manifest  the  power  to  resist  fracture 
before  illustrated,  and  to  this  effect  the  hollow  cylindrical  form  of 
their  diaphyses  greatly  contributes.  Indeed,  if  the  weight  of  the 
shaft,  and  the  length,  be  the  same,  its  strength  as  a  lever  varies 
(within  certain  limits)  directly  as  its  diameter^  i.  e.  if  the  shaft  of  the 
OS  femoris,  weighing  sixteen  ounces,  and  being  seventeen  inches 
long,  is  hollow  and  one  inch  in  diameter,  it  is  twice  as  strong  as 
if  of  the  same  length  and  weight,  and  condensed  into  a  solid  rod 
half  an  inch  in  diameter.  Thus  we  perceive  the  advantage  result- 
ing from  the  function  of  the  medullary  canal  in  the  long  bones ; 
viz.,  to  increase  the  strength  of  the  bone,  the  amount  of  material  in 
it  being  given.  Every  blade  of  grass,  indeed,  is  constructed  on  the 
same  principle.  This  arrangement  is  also  apparently  more  conso- 
nant with  the  power  of  rapid  repair  after  fracture  in  the  long  bones; 
in  which  fractures  must  necessarily  be  most  frequent.  Finally,  the 
existence  of  the  cavity  necessitates  the  presence  of  a  substance  to 
fill  it,  which  is  accomplished  by  the  marrow,  as  above  explained 
(p.  341).. 

4.  But  the  long  bones  are  also  for  support,  especially  in  the  lower 
extremities ;  and  in  this  relation  some  interesting  facts  are  ascer- 
tained. The  strength  of  bone  as  a  mere  column  of  support,  its 
weight  and  general  conformation  being  the  same,  varies  inversely 
with  the  square  of  its  length;  i.  e.  an  os  femoris  8 J  inches  long,  and 
weighing  17  ounces,  would  be  four  times  as  strong  as  one  twice  as 
long,  but  of  the  same  weight.  Hence  the  short  bones  are  vastly 
stronger  in  proportion,  in  this  respect.  Indeed,  we  may  imagine 
the  lower  extremities  of  an  animal  to  become  incapable  of  sustain- 
ing its  weight,  from  a  slight  increase  of  their  length,  while  the  bones 
become  no  heavier.  Hence  only  animals  having  light  bodies  have 
long  extremities ;  while  the  very  heavy  have  proportionally  short 
columns  of  support.  Hence, 'also,  the  tarsus  and  carpus  of  the 
lower  animals,  as  well  as  man,  consist  of  short  bones.  Moreover, 
the  speed  of  animals  cannot  be  increased  in  proportion  to  size;  the 
skeleton  becoming  at  length  so  heavy  that  much  muscular  force  is 
exhausted  in  merely  sustaining  it. 

5.  Man  has  comparatively  a  long  column  of  support,  especially  no 
far  as  the  os  femoris  is  concerned ;  and  thus  the  power  of  rapid 
locomotion  is  secured.     The  diminution  of  strength  consequent  on 


350  THE   TISSUES. 

its  length  is,  however,  in  part  compensated  by  the  fact  that  the 
peculiar  attachment  of  the  cervix  femoris  converts  this  bone  (as  a 
column  of  support)  into  an  arch;  and  thus  brings  its  elasticity  also 
to  bear  on  its  strength. 

Development  of  the  Bones. 

Most  of  the  bones  are  developed  in  cartilages,  which,  in  the  aggre- 
gate, constitute  the  cartilaginous  skeleton  (p.  316);  the  rest  being 
formed  in  a  soft  blastema.  The  former  are  sometimes  termed  pri- 
mary^ and  the  latter  secondary^  bones. 

The  cartilages  constituting  the  cartilaginous  skeleton  are  deve- 
loped like  other  true  cartilages  (p.  317),  and  grow  in  a  similar  man- 
ner, till  ossification  commences  within  them ;  and  which  extends 
from  within  outwards  till  the  whole  is  converted  into — or,  more 
accurately  speaking,  is  replaced  by — bone. 

The  cartilaginous  skeleton,  and  its  conversion  into  the  various 
bones,  will  first  be  described ;  and  then  the  development  of  the 
secondary  bones  (the  flat  bones  of  the  cranium,  &c.)  will  be  ex- 
plained. 

It  follows  that  the  primary  cartilaginous  skeleton  is  not  so  complete 
as  the  osseous  skeleton ;  but  it  also  presents  some  portions  which 
either  remain  in  a  cartilaginous  state,  or  are  subsequently  entirely 
removed.  It  consists— yirs^,  of  a  complete  vertebral  column,  with  as 
many  cartilages  as  there  are  afterwards  osseous  vertebra),  and  Avith 
intervertebral  ligaments;  secondly^  cartilaginous  ribs  and  sternum  ; 
thirdly^  cartilaginous  extremities  with  as  many  pieces  as  there  are 
subsequently  bones,  except  that  the  pelvic  cartilages  are  in  a  single 
mass;  and,  fourthly,  an  incomplete  cartilaginous  cranium.  The  last 
forms  a  continuous  cartilaginous  mass  at  first,  and  corresponds  to 
the  occipital  bone  (except  its  upper  half),  the  sphenoid  (except  the 
external  lamina  of  the  pterygoid  process),  the  mastoid  and  petrous 
portions  of  the  temporal  bone,  the  ethmoid,  the  inferior  turbinated 
bone,  the  hyoid  bone,  and  the  ossicula  auditfis.  The  cartilaginous 
cranium  also  presents  the  parts  before  alluded  to,  as  either  remain- 
ing in  a  cartilaginous  state,  or  entirely  disappearing — as  Meckel's 
process,  two  cartilaginous  lamellae  below  the  nasal  bones,  a  narrow 
band  connecting  the  styloid  process  with  the  hyoid  bone;  another 
extending  from  the  outer  part  of  the  ala  p)arva  to  the  lamina  crib- 
rosa:  and  a  third  reaching  upwards  and  forwards  from  the  carti- 
laginous mastoid  and  petrous  portions  of  tlie  temporal  bone. 


DEVELOPMENT  OF  THE  BONES.  351 

Tliius  in  the  cartilaginous  cranium  the  vault  is  entirely  wanting, 
and  almost  all  tlie  lateral  portions,  as  well  as  nearly  all  of  what 
afterwards  becomes  the  facial  bones.  The  parts  not  formed  of  car- 
tilage are,  however,  closed  by  a  fibrous  membrane,  so  that  the  cra- 
nium is  nevertheless  at  this  time  complete.  It  is  also  in  this  mem- 
brane that  the  secondary  bones  are  subsequently  developed. 

The  changes  which  occur  in  the  primordial  cartilaginous  skeleton 
are,  therefore,  of  three  kinds:  1.  Some  portions  subsequently  dis- 
appear altogether,  as  already  stated.  2.  Other  portions  undergo 
subsequent  development  with  the  rest  of  the  skeleton,  constituting 
the  permanent  cartilages  of  the  nose,  joints,  symphyses,  and  syn- 
chondroses. 3.  The  third  and  greater  part  finally  becomes  ossified, 
forming  all  the  bones  of  the  trunk  and  extremities,  and  a  great  part 
of  those  of  the  cranium.  It  is  this  portion — the  ossifying  cartilages — 
whose  changes  are  to  be  described  here. 

The  general  description  of  the  ossification  of  the  cartilages  is  as 
follows:  At  one  or  more  points  in  their  interior,  calcareous  matter 
begins  to  be  deposited,  simultaneously  with  a  change  in  the  elements 
of  the  cartilage.  The  latter,  in  most  cases,  ceases  to  grow  in  one 
direction  while  this  change  is  going  on,  and  is  therefore  soon  en- 
tirely converted  into  bone;  while  in  other  directions  its  growth 
continues,  so  that  a  new  cartilaginous  material  is  ofi^ered  for  the 
progressive  increase  of  the  bone.  When  the  bone  has  attained  to 
its  ultimate  length,  the  cartilage  becomes  completely  ossified,  and 
ceases  to  be  developed,  its  perichondrium  now  being  a  periosteum. 
The  diameter  of  the  bone  is,  however,  still  increased  by  the  forma- 
tion of  concentric  laminae  (the  fundamental  laminae,  p.  328)  under- 
neath the  periosteum,  from  the  blood-plasma  in  the  periosteal  vessels. 

The  minute  changes  in  the  ossifying  cartilage  are  next  to  be  de- 
scribed, and  Kolliker's  view  of  this  difficult  subject  will  be  adopted 
as  the  most  satisfactory. 

It  should,  however,  be  premised  that  the  cancellated  tissue  alone 
is  developed  from  the  primordial  cartilages,  the  compact  tissue  being 
derived  from  another  source.  When,  therefore,  the  cartilages  have 
become  ossified,  the  bones  thus  formed  all  consist  entirely  of  cancel- 
lated tissue.  The  following  description,  therefore,  of  the  ossification 
of  the  cartilages  is  the  history  of  the  development  of  the  cancellated 
hone-substance,  wherever  found : — 

I.  Before  ossification  actually  commences,  vessels  begin  to  pene- 
trate the  ossifying  cartilages.     They  appear  from  and  after  the 


352  THE   TISSUES. 

middle  of  foetal  life,  preceding  by  a  longer  or  shorter  time  the  ap- 
pearance of  the  centres  of  ossification,  and  accompanying  the  latter 
as  they  increase.  They  may  still  be  seen  in  the  epiphyses  of  the 
long  bones  in  a  person  even  eighteen  years  old.  They  always  lie 
in  wide  canals  (g  J 5  to  3  ^^  of  an  inch  even  in  a  foetus  of  five  months) 
excavated  in  the  cartilage,  and  bounded  by  narrow,  elongated  car- 
tilagecells.  They  enter  the  cartilage  from  the  perichondrium  at 
first,  and,  after  an  osseous  centre  exists,  from  the  border  of  the 
latter  also ;  proceeding  in  straight  lines  in  various  directions,  and 
giving  off  a  few  branches,  which  seem  not  to  anastomose  at  all,  but 
to  terminate  in  blind,  club-shaped  dilatations.  These  canals  are 
produced  by  an  absorption  of  the  elements  of  the  original  cartilage- 
substance,  and  they  originally  contain  a  plastic  material  (cartilage- 
marrow)  composed  of  minute  rounded  cells,  from  which  true  blood- 
vessels are  developed.  Of  the  vessels  themselves,  sometimes  but 
one  large  one ;  frequently  two,  distinctly  arterial,  with  muscular 
walls ;  again,  only  capillaries  in  various  numbers — are  found  in  a 
single  canal.  It  is  not  precisely  understood  how  the  circulation  is 
carried  on  by  them.  Their  object  is,  doubtless,  to  afford  a  greater 
amount  of  nutritive  material,  both  for  the  changes  in  the  cartilage 
preparatory  to  ossification,  and  for  the  development  of  the  bone 
itself.  That  they  are  merely  an  accidental  production,  as  H.  Meyer 
maintains,  is  highly  improbable. 

II.  Together  with  the  formation  of  vessels  in  the  cartilages,  the 
elements  of  the  latter  undergo  important  changes.  The  cartilage- 
cavities,  before  of  small  size,  and  containing  but  few  cells,  begin  to 
grow,  and  successive  generations  of  cells  to  be  produced  in  them  in 
the  following  manner:  Each  cell  is  first  divided  into  two  by  seg- 
mentation transverse  to  the  line  of  ossific  advance;  these  are  again 
subdivided,  and  the  process  repeated  till  long  lines  of  cartilage-cells 
extend  in  the  elongated  cartilage-cavities  from  the  border  where 
ossification  has  taken  place.'  The  size  of  the  cavities,  however, 
does  not  increase  after  birth.  When  the  ossification  of  the  cartilage 
proceeds  in  one  direction  only,  they  are  grouped  in  rows  at  the 
border  of  the  cartilage,  in  which  the  long  cavities  are  being  de- 
veloped. This  is  best  seen  in  the  extremities  of  the  shafts  of  the 
larger  long  bones;  the  rows  of  cavities  being  arranged  in  parallel 
lines,  close  together,  and  of  considerable  length,  as  shown  by  Fig.  225. 

'  Tomes  and  De  Morgau. 


DEVELOPMENT   OF   THE   BOXES. 


353 


Where,  however,  the  ossification  ex-  Fig*  225. 

tends  in  all  directions  from  a  centre, 
the  cartilage-cavities  are  confusedly 
grouped  in  roundish  or  oval,  irregular 
little  masses,  as  in  the  short  bones,  and 
the  epiphyses  of  the  long  bones.  In 
both  these  cases,  however,  the  cavities 
containing  the  cells  (the  latter  being 
in  a  single  or  double  linear  series,  or 
in  a  more  globular-mass),  are  the  elon- 
gated original  cartilage-cavities.  The 
thickness  of  the  layer  around  and  be- 
yond the  bone,  which  presents  the  ar- 
rangement of  cells  j  ust  described,  varies 
in  the  different  cartilages;  being  Jg  to 
o'4  of  an  inch  in  the  shafts  of  the  long 
bones,  and  very  thin  around  the  os- 
seous centres,  in  the  epiphyses,  and  in 
the  short  bones.  It  is  always  yellowish, 
streaky,  transparent,  and  apparently 
fibrous;  while  the  surrounding  cartilage 
is,  as  usual,  bluish-white,  with  a  hya- 
line or  granular  intercellular  substance. 

III.  The  preparations  for  ossification 
being  completed  by  the  development 
of  the  vessels  and  the  arrangement  of 
the  cartilage-cells  just  described,  the 
osseous  tissue  now  begins  to  appear. 
And  as  true  cancellated  bone-substance  consists  originally  of  only 
the  lacunae  and  pores  and  the  surrounding  true  osseous  tissue,  and 
the  cancelli  (with  their  marrow  and  its  vessels),  we  have  to  inquire 
how  these  are  developed  respectively. 

1.  The  true  osseous  tissue  is  usually  developed  before  the  lacunae 
and  pores  are  formed;  and  its  formation  occurs  mainly  in  the  inter- 
cellular substance  of  the  cartilage,  its  cells  still  remaining  unchanged. 
The  first  apparent  change  in  this  is  the  deposit  of  very  fine  granules 
of  the  earthy  constituents  of  bones,  varying  in  size  from  an  im^ 
measurable  minuteness  up  to  tsooo  to  goVo  of  an  inch  in  diameter. 
When  the  cells  are  disposed  in  rows  at  the  ossifying  border,  this 
disposition  of  earthy  matter  always  forms  colunjns  between  the 
23 


Vertical  section  of  cartilage  at  seat  of 
ossification.  The  clusters  of  cells  are 
arranged  in  columns,  the  intercellular 
spaces  between  them  being  l-3250th  of 
an  inch  in  breadth.  At  the  lower  end 
of  the  figure  osseous  fibres  are  seen  oc- 
cupying the  intercellular  spaces,  at  first 
bounding  the  clusters  laterally,  then 
splitting  them  longitudinally,  and  en- 
circling each  separate  cell.  The  greater 
opacity  of  this  portion  is  due  to  a  three- 
fold cause :  the  increase  of  osseous  fibres, 
the  opacity  of  the  contents  of  the  cells, 
and  the  multiplication  of  oil-globules. 


354 


THE    TISSUES. 


Fig.  226. 


^Jsi^. 


sl5|l|"|^'iV} 

i|l44l|]|||lf 
?.sfili° 


J"s5P: 


rows  of  cartilage-cells,  forming  pointed  tooth-like  processes  between 
tlie  individual  cells,  and  surrounding  the  lower  portion  of  the  rows 
like  short  tubes.  (Fig.  226.)  If,  however, 
this  granular  deposit  be  traced  back  from 
the  ossifying  margin  into  the  substance  of 
the  new  bone,  it  gradually  becomes  clearer, 
more  homogeneous  and  transparent,  and 
ultimately  acquires  the  aspect  of  perfect 
bone ;  the  earthy  granules  apparently  be- 
coming gradually  fused-  together,  and  thus 
disappearing  as  isolated  distinguishable 
particles.  And  thus  the  true  osseous  tissue 
is  developed  (though  not  entirely,  as  will 
appear),  in  the  matrix  or  intercellular  sub- 
stance of  tile  ossifying  cartilage.  (Fig.  225.) 
2.  But  while  the  intercellular  substance 
thus  gives  place  to  true  bony  tissue,  the 
cartilage- cells  also  are  being  converted  into 
the  future  lacunge  and  pores  of  the  bones. 
And  it  may  now  be  regarded  as  established 
by  Kolliker's  investigations,  that  each  car- 
tilage-cell becomes  converted  into  a  single 
lacuna  and  its  pores  as  follows,  except 
where  several  are  fused  together  into  a  com- 
pound lacuna:  1.  The  cartilage-cells  be- 
come filled  with  concentric  layers  of  osse- 
ous tissue,  the  external  one  being  formed 
first,  and  the  last  or  internal  layers  show- 
ing imperfections  or  indentations.  This 
proceeds  till  the  cartilage-cell  is  more  or  less  completely  filled  with 
the  osseous  matter,  though  a  cavity  always  remains  (the  future  la- 
cuna), containing  generally  the  nucleus  of  the  original  cartilage- 
cell,  and  a  fluid  plasma.  2.  Minute  canals  (the  pores)  are  next 
formed  by  actual  absorption^  of  the  bone-substance;  and  thus  are 
completely  perforated  by  them,  both  the  osseous  tissue  deposited 
within  the  cartilage-cells,  and  that  previously  found  in  the  intercel- 
lular substance  of  the  cartilage.  3.  Finally,  the  osseous  tissue  within 
the  cells  becomes  fused  with  that  preformed  between  them,  so  that 


Vertical  section  through  the  car- 
tilage and  incipient  bone  of  the 
diaphysis  of  the  femur  ;  in  an  in- 
fant a  fortnight  old.  a.  Cartilage- 
cells  arranged  in  longitudinal  piles 
near  the  ossified  surface.  6.  Plane 
of  ossification,  the  osseous  matter 
inclosing  the  basis  of  the  piles, 
c.  Close  osseous  network  first 
formed,  d.  Cancellated  structure 
formed  by  the  absorption  of  parts 
of  this.  e.  its  cancelli  filled  with 
medulla. 


Tlie  cause  of  this  absorption  is  not  understood. 


DEVELOPMENT  OF  THE  CANCELLI.  3oo 

no  distinct  walls  oftlic  Ificunai  can  be  recognized  (p.  324);  and  thus 
the  formation  of  the  whole  of  the  true  osseous  tissue  is  accounted 
for,  together  with  the  lacunoe  and  pores. 

3.  The  cancelli  are  developed  by  absorption  of  more  or  less  per- 
fectly formed  bone-substance.  During  the  ossification  of  the  shafts 
of  the  long  bones,  the  osseous  tissue,  to  the  thickness  of  gV  to  ^'g 
of  an  inch,  is  compact,  and  without  a  trace  of  larger  cavities ;  being 
composed  partly  of  the  ossified  intercellular  substance  of  the  carti- 
lage, and  partly  of  the  cells  of  the  latter,  more  or  less  advanced  in 
their  transformation  into  lacunas  and  pores.  But  beyond  this  depth, 
cavities  at  first  small,  and,  more  internally,  larger,  are  seen,  which 
appear  to  be  eaten  out  of  the  bone,  and  involve  both  the  osseous 
tissue,  the  lacunae,  and  pores,  and  the  still  unossified  portion  of  the 
cartilage.     How  this  absorption  takes  place  is  also  unknown. 

Thus  it  appears  that  while  the  formation  of  bone  progresses  in 
one  direction,  an  active  resorption  of  a  part  of  the  bone  thus  formed 
follows.  The  cancelli  thus  formed  are  of  different  form,  size,  and 
direction,  in  different  bones. 

As  the  medullary  cavities  or  cancelli  become  developed,  they  are- 
also  filled  with  a  soft  reddish  substance — the  foetal  medulla — con- 
sisting at  first  of  merely  a  small  quantity  of  fluid  and  many  rounded 
cells  containing  one  or  two  nuclei,  and  faintly  granular  contents. 
Subsequently,  however,  these  cells  become  identical  with  those 
already  described  as  occurring  in  certain  bones  in  the  adult  (p.  3-iO); 
and  are  developed  in  the  usual  way  into  areolar  tissue,  bloodvessels,, 
fat-cells,  and  nerves — or  the  true  marrow  of  the  bones  (p.  340). 
The  vessels  are  formed  very  rapidly,  and  the  fat,  and  then  the  nerves, 
afterwards;  so  that  vessels  appear  in  the  cancelli  very  soon  after 
the  formation  of  the  latter.  The  fat-cells  are  few  even  at  birth,  and 
the  nerve  filaments  much  fewer  than  subsequently ;  the  medulla 
being  now  colored  entirely  red  by  the  blood,  and  the  light-reddish 
medulla-cells.  These  vessels  extend  into  the  cancelli  from  the  car- 
tilage vessels  already  described  (p.  352). 

Thus  the  bone-substance  formed  from  cartilage  alone,  is  merely 
cancellated.  Hence  the  shafts  as  well  as  the  epiphyses  of  the  long 
bones,  at  first  contain  only  cancellated  or  spongy  tissue;  the  com- 
pact bone-substance  being  subsequently  superadded  from  another 
source,  as  next  to  be  described. 


356  THE   TISSUES. 

Development  of  the  Compact  Bone- Substance. 

This  is  developed  from  a  layer  of  plasma,  underneath  and  afforded 
by  the  vessels  of  the  periosteum.  In  the  foetus  of  five  months,  this 
layer  is  so  firm  as  to  be  detached  with  the  fully  formed  periosteum, 
forming  upon  the  latter  a  moderately  thick,  soft,  whitish -yellow 
lamella  very  much  resembling  immature  collagenous  (white  fibrous) 
tissue,  and  containing  granular,  oval,  or  round  nucleated  cells, 
s^V^  t^  T2't)(J  of  ^^  i^ch  in  diameter.  This  lamella  is  very  exten- 
sively connected  with  the  superficial  layer  of  the  bone,  and  on  being 
detached,  a  few  little  fragments  of  bone  and  scattered  masses  of 
reddish  soft  medulla  from  the  most  superficial  cancelli,  will  be  seen 
on  the  inner  surface. 

The  cells  just  mentioned  appear  exactly  like  the  foetal  medulla- 
cells,  but  not  at  all  like  those  of  cartilage.  And  it  appears  that  the 
collagenous  matrix  is  next  ossified  by  the  simple  uniform  deposit 
of  the  calcareous  salts,  though  without  the  previous  appearance  of 
calcareous  granules  as  before  described  (p.  354);  while  from  the 
cells  the  lacunae  and  pores  are  developed. 

Bone  formed  in  this  way,  however,  does  not  constitute  connected 
and  parallel  layers,  but  interrupted  reticular  lamelloB,  and  the  spaces 
left  between  the  latter  ^^^  to  -g^^  of  an  inch  in  diameter,  are  the 
rudiments  of  the  Haversian  canals  of  the  compact  bone-substance. 
These  spaces  at  first  contain  only  the  unossified  portion  of  the 
plasma  just  described.  But  vessels  communicating  with  those  of  the 
interior  of  the  bone  (of  the  cancelli),  and  with  those  of  the  perios- 
teum, soon  appear  in  them;  as  well  as  the  usual  light-reddish  me- 
dulla-cells, and  certain  peculiar  cellular  corpuscles,  with  from  three 
to  twelve  or  more  vesicular  nuclei  and  nucleoli,  which  are  probably 
referable  to  the  multiplication  of  the  latter.  The  vessels  just  men- 
tioned are  the  future  Haversian  vessels;  and  finally  the  Haversian 
rods  consisting  of  the  concentric  (or  spiral)  lamellae,  with  their 
lacunas  and  pores,  are  developed  around  the  vessels — the  outer  la- 
mellae first;  and  thus  the  development  of  the  compact  bone-sub- 
stance is  completed.  The  manner  in  which  the  interrupted  laminae 
are  formed,  and  which  are  now  seen  to  constitute  the  interstitial  (or 
inter- Haversian)  bone-substance  (p.  330),  is  shown  by  Fig.  227,  A 
vertical  section  of  tlie  sub-periosteal  layer  of  developmg  osseous 
tissue  is  shown  by  Fig.  228. 

The  compact  tissue  continues  to  be  formed,  as  just  described, 


COMPACT   BONE-SUliSTANCE  — DEVELUPMEKT. 


dy< 


until  the  bone  attains  to  nearly  its  full  development,  when  the 
general  (fundamental)  laminae  (p.  828)  are  formed  externally  to  the 
Haversian  rods  from  a  plasma  afforded  by  the  vessels  of  the  peri- 


Fig.  227. 


Fig.  228. 


Fig.  227.  Vertical  section  from  tlie  surface  of  the  shaft  of  the  metatarsus  of  the  calf;  magnified 
45  diameters.  A.  Periosteum,  b.  Ossifying  blastema,  c.  Young  layer  of  bone  with  wide  cavities 
(a)  in  which  are  lodged  remains  of  the  ossifying  blastema,  and  reticular  spicula  (b),  which  towards 
the  blastema  present  a  tolerably  abrupt  border,  d.  More  developed  layer  of  bone,  with  Haversian 
canals  (c)  surrounded  by  their  lamella;.   (Kijlliker.) 

Fig.  228.  Sub-periosteal  layer  from  the  extremity  of  the  shaft  of  the  ossifying  tibia.  The  cartilage 
and  more  open  bony  tissue  have  been  scraped  off  from  the  inside  of  the  crust,  except  at  (a),  where  a 
dark  shade  indicates  a  few  vertical  osseous  areolae,  out  of  focus  and  indistinctly  seen.  The  part 
(a,  h)  of  the  crust  is  ossified  ;  between  (b  and  c)  are  the  clear  reticular  fibres,  into  which  the  earthy 
deposit  is  advanciug.     (Magnified  150  diameters.) 

osteum,  to  constitate  the  structure  represented  by  Fig.  217.  And  by 
these  the  thickness  of  the  bone  is  increased.  But,  while  this  change 
is  going  on  in  the  outer  portions  of  the  shaft  of  the  long  bones, 
another  is  occurring  in  its  interior;  viz.,  the  whole  original  shaft  of 
cancellated  bone-substance,  formed  from  the  cartilage,  becomes  by 
degrees  absorbed,  and  thus  the  medullary  canal  is  formed.  The 
extremities,  however,  of  the  long  bones  being  formed  entirely  from 
the  original  cartilages — the  latter  constantly  growing  and  becoming 
ossified,  while  the  bone  is  increasing  in  size — are  not  absorbed  in- 
ternally ;  but,  like  the  short  bones  (which  also  are  not  formed  from 
a  collagenous  matrix  derived  from  the  periosteal  vessels),  continue 
to  retain  the  cancellated  structure  through  life.  It  is,  however,  suf- 
ficiently obvious  that  the  medullary  canal  is  formed,  not  at  the  ex- 
pense merely  of  the  cancellated  substance  in  the  shaft  of  the  foetal 


358  THE   TISSUES. 

bones;  but  that  it  also  implies  an  absorption  of  a  considerable  por- 
tion of  the  compact  tissue  at  first  formed.  In  fact,  while,  during 
the  growth  of  the  bones  new  osseous  tissue  is  constantly  deposited 
externally,  that  also  which  is  already  formed  is  as  constantly  ab- 
sorbed in  its  interior.  So  that  during  its  growth  each  bone  is  seve- 
ral times  regenerated  ;  and  the  humerus,  for  instance,  of  the  adult, 
does  not  contain  an  atom  of  the  osseous  tissue  existing  in  it  at 
birth. 

The  fact,  however,  that  a  thin  layer  of  compact  bone-substance  is 
formed  by  the  periosteum  on  the  exterior  of  the  short  bones  also, 
has  been  stated.  Absorption  and  regeneration  of  the  cancellated 
structure  occurs  also  in  the  short  as  well  as  in  the  long  bones;  but 
far  more  slowly.  Hence  in  them  (e.  g.  the  vertebrae)  we  find  more 
or  less  still  remaining,  of  the  earlier  bone-structure.  It  should  also 
be  added  that  some  of  the  Haversian  vessels  being  enlarged,  con- 
stitute the  vasa  nutrilia  of  the  interior  of  the  long  bones.  And 
finally,  when  the  long  bones  attain  to  their  full  length,  the  osseous 
tissue  of  the  diaphysis  and  of  the  epiphyses  becomes  completely 
fused  together,  the  disk  of  cartilage  which  hitherto  intervened,  now 
disappearing  entirely;  and  the  vessels  originally  distributed  sepa 
rately  to  the  shaft  and  the  extremities,  at  last  forming  anastomoses, 
though  not  very  numerous,  through  the  last  formed  portion  of  the 
bones.  If  the  question  occurs  how  bone  is  developed  externally  at 
points  covered  directly  by  tendons  and  ligaments,  without  the  inter- 
vention of  periosteum  (p.  846),  it  may  be  suggested  that  these  also 
must  and  do  increase  in  size,  and  are  also  constituted  of  the  colla- 
genous tissue,  like  the  blastema  afforded  by  the  periosteum.  At 
any  rate,  interstitial  changes  must  be  occurring  in  the  ligaments 
and  tendons  till  they  attain  to  their  full  development;  simulta- 
neously with  which,  similar  changes  must  occur  in  the  surface  and 
the  size  of  the  bones  to  which  they  are  attached.  It  is  only  by 
admitting  interstitial  changes  in  bone,  moreover,  that  we  can  account 
for  the  increase  in  size  of  their  foramina,  and  in  the  length  of  the 
lamina)  of  the  vertebra3,  &c. 

Devehjiment  of  the  Secondary  Bones. 
Bones  not  previously  cartilaginous  occur  in  man,  only  in  the 
roof  of  the  cranium  and  the  face.     They  are  called  secondary,  be- 
cause their  development  does  not  commence  till  after  that  of  the 
primordial  or  cartilaginous  cranium  (p.  850).     This  class  includes 


DEVELOPMENT   OF  THE   SECONDARY   BONES.  359 

the  upper  half  of  the  expanded  portion  of  the  occipital  bone,  the 
parietal  and  frontal  bones,  the  squamous  portion  and  tympanic  ring 
of  the  temporal,  all  the  bones  of  the  face,  except  the  inferior  tur- 
binated bones ;  and  apparently  the  internal  lamella  of  the  pterygoid 
process  of  the  sphenoid  bone.  It  will,  however,  appear  that  these 
bones  are  developed  in  precisely  the  same  manner  as  the  periosteal 
layers,  or  compact  tissue  of  the  other  bones. 

The  secondary  bones  of  the  cranium  all  commence  in  a  mem- 
braniform  blastema  lying  between  the  dura  mater  and  the  integu- 
ments, whose  growth  advances  with  the  development  of  the  osseous 
tissue  within  it.  The  latter  commencing  in  a  single  point,  radiates 
in  all  directions  and  thus  forms  a  delicate  lamina  of  reticulated 
osseous  spicula3,  giving  off  slender  rays  into  the  still  unossified 
blastema.  Minute  examination  shows  that  the  spiculge  are  formed 
by  the  ossification  of  the  elements  of  the  blastema,  though  to  a 
certain  extent  the  latter  is  absorbed  to  give  place  to  them,  while  it 
still  fills  the  interstices  between  them  ;  and  that  the  formation  of  the 
bone-tissue  proceeds  exactly  in  the  same  way  as  in  the  periosteal 
layer  of  the  primary  bones.  {KoUiker.)  At  first,  the  growth  pro- 
ceeds in  a  superficial  plane  only,  the  rays  forming  a  network  as  they 
come  into  contact  with  each  other,  as  shown  in  Fig.  229.  Addi- 
tional layers  are,  however,  soon  added  to  both  surfaces  of  the  ori- 
ginal one,  and  thus  the  structure  becomes  thicker,  and  at  the  same 
time  also  more  compact.  The  thickening  layers  are,  however,  re- 
ferable to  the  periosteum  which  is  found  on  the  secondary  bones 
soon  after  their  development  has  begun ;  so  that  in  fact  only  the 
primary  layer  presents  any  apparent  peculiarity  in  development. 
The  bone  increases  in  extent  by  the  formation  of  new  blastema  in 
contact  with  that  just  about  to  be  ossified,  until  it  has  attained  to 
its  full  size;  and  it  is  constantly  increasing  in  thickness  by  the  ad- 
dition of  the  periosteal  layers  as  just  explained.  Interstitial  changes 
are  also  at  the  same  time  going  on,  and  the  final  result  is,  the  for- 
mation of  the  bones  with  their  compact  layers  and  Haversian  canals; 
and  their  cancelli  internally,  constituting,  in  case  of  the  cranial 
bones,  the  diploe.  The  cells  in  the  blastema  never  resemble  carti- 
lage-cells, except  those  at  the  edges  of  the  newly  formed  bone.  But 
Kolliker  doubts  if  even  these  be  true  cartilage-cells.  It  has  already 
been  seen  that  it  is  not  true  cartilage  which  connects  the  cranial 
bones  together  in  the  adult,  but  collagenous  tissue  instead  (p.  347). 
There  is  usually  but  one  centre  of  ossification  for  each  of  the  se- 


360 


THE    TISSUES. 


condarj  cranial  bones;  or  for  each  lialf,  when  one  is  symmetrical. 
The  spaces  left  between  them  at  birth,  from  the  fact  that  their  angles 

Fig.  229. 


Process  of  ossification  in  parietal  bone  of  an  embryo-sheep  of  two  and  a  half  inches  in  length. 
The  small  upper  figure  represents  the  bone  of  the  natural  size.  The  larger  figure  is  magnified  about 
12  diameters.  The  curved  line  (a,  6)  marks  the  height  to  which  the  subjacent  cartilaginous  lamella 
extended.  A  few  insulated  particles  of  bone  are  seen  near  the  circumference,  an  appearance  which 
is  quite  common  at  this  stage. 


are  still  undeveloped,  are  termed  Vae  fonianelles ;  and  this  condition 
allows  an  overlapping  of  the  bones  of  the  vault  of  the  cranium,  by 
which  parturition  is  very  much  facilitated. 

The  secondary  bones  are  more  vascular  while  growing  than  after- 
wards; more  so  even  than  the  periosteal  layer  of  the  other  bones; 
many  of  the  vascular  canals  afterwards  becoming  much  contracted, 
or  even  obliterated. 

For  the  facts  in  regard  to  the  precise  period  when  each  bone  is 
developed  in  the  foetus,  tlie  works  on  anatomy  are  referred  to;  the 
law  being  that  the  bones,  and  even  the  parts  of  bones,  first  needed  in  the 
skeleton  are  first  developed. 

Remarks. — 1.  In  regard  to  the  amount  of  osseous  tissue  developed 
in  a  given  time  in  a  young  animal,  the  following  facts  may  be 


REMAKKS   ON   BONE-DEVELOPMENT.  361 

noted.  Boussingault  determined  from  his  experiments  that  the 
skeleton  of  a  pig  increases  daily  during  the  first  eight  months  after 
birth,  about  2.9  drachms  in  weight  (average) ;  amounting  to  a  for- 
mation of  about  1.55  drachm  daily  of  osteine,  and  1.35  drachm  of 
earthy  matter,  including  .6  drachm  of  phosphoric  acid.  Subse- 
quently to  the  eleventh  month,  the  daily  increase  in  weight  averages 
but  1.5  drachm  daily  ;  there  being  only  about  .65  drachm  of  earthy 
matter,  including  .35  drachm  of  phosphoric  acid. 

2.  Much  discussion  has  arisen  on  the  question  whether  bone  is 
always  developed  from  cartilage — those  who  maintain  the  affirma- 
tive asserting  that  the  blastema  in  which  the  periosteal  layers  of 
the  primary  bones,  and  the  whole  of  the  secondary  bones  are  deve- 
loped, is  also  cartilage,  but  in  its  rudimentary  stage  of  development. 
It  has  already  been  seen  that  the  cartilage-cells  cannot  at  first  be 
distinguished  from  the  primordial  cells  of  other  tissues.  So  far  as 
this  fact  is  considered,  therefore,  it  is  as  valid  a  proof  of  the  assump- 
tion that  the  blastema  is  a  rudimentary  collagenous,  as  that  it  is  a 
rudimentary  cartilaginous  tissue.  The  fact,  however,  that  the  inter- 
sutural  substance  contains  no  chondrine  and  never  becomes  cartilage, 
though  remaining  till  late  in  life,  and  finally  ossifies,  especially  in- 
ternally, without  going  through  that  change;  it  being,  on  the  other 
hand,  white-fibrous  tissue  (the  sutural  ligament,  p.  347) — militates 
against  the  idea  that  the  secondary  bones  are  developed  from  carti- 
lage. Moreover,  Kolliker  appears  to  be  correct  in  the  assertion 
that  the  periosteal  layers  of  the  primary  bones  are  developed  in 
precisely  the  same  manner.  We,  therefore,  believe  with  him — 
against  Meyer  and  many  other  histologists — that  while  the  cancel- 
lated substance  of  the  primary  bones  is  developed  in  cartilage,  the 
secondary  bones,  as  well  as  the  periosteal  layers  of  the  primary,  are 
developed  in  a  matrix  homologous  with  white  fibrous  tissue. 

Indeed,  if  we  trace  the  development  of  the  skeleton  through  the 
animal  series,  we  find,  1,  that  in  all  vertebrated  animals  those  parts 
of  it  requiring  some  degree  of  firmness  during  the  early  periods  of 
development,  consist  of  cartilage ;  while  the  rest  is  developed  from 
a  softer  substance.  The  cartilaginous  portion  will  constitute  more 
or  less  of  the  whole  future  skeleton,  according  to  the  habits,  &c.,  of 
the  animal ;  e.  g.  the  cranium  of  the  pig  is  more  exclusively  carti- 
laginous than  the  human  cranium.  2.  In  some  of  the  lowest  ver- 
tebrata  (cartilaginous  fishes),  the  skeleton  remains  in  the  cartilagin- 
ous state  through  life.     3.  In  all  the  land  vertebrata,  however,  a 


362  THE   TISSUES. 

firmer  skeleton  is  required,  and  the  greater  part  of  the  cartilaginous 
skeleton  therefore  becomes  replaced  by  bone;  while  equally  firm 
bones  are  at  the  same  time  developed  from  the  softer  blastema  be- 
fore described.  Thus  there  appears  to  be  no  necessity  for  cartilage 
as  a  matrix  for  the  development  of  bone,  unless  required  on  account 
of  its  greater  firmness;  and  Meyer's  assumption  that  everything 
in  which  bone  is  formed  is  cartilage^  is  both  a  begging  of  the  ques- 
tion, and,  at  the  same  time,  incorrect. 

3.  The  manner  of  development  of  bone  is,  however,  essentially  the 
same,  whether  cartilage  or  a  soft  blastema  be  the  matrix.  In  both 
cases  it  is  developed  as  an  entirely  new  tissue,  and  the  pre-existing 
tissue  disappears  and  gives  place  to  it.  It  has  been  seen  that  the 
true  osseous  tissue  is  first  developed  in  the  intercellular  substance  of 
the  cartilages,  and  finally  the  whole  of  it  appears  to  be  converted 
into  bone.  There  are,  however,  no  facts  indicating  that  chondrine 
can  be  converted  into  glutin,  or  cartilageine  into  osteiue  (p.  100). 
This  element  of  the  cartilage  is  therefore  merely  replaced  hy  the 
osseous  tissue.  On  the  other  hand,  it  has  been  seen  that  the  carti- 
\dige-cavities  remain  for  a  time,  increasing  in  size  and  changing  their 
forms;  but  the  cartilage-ceZ/s  within  them,  after  increasing  in  num- 
ber, disappear  (except  probably  their  nuclei),  the  lacunae  (and  pores) 
taking  their  place  in  part  (p.  354,  2). 

Again,  while  the  secondary  bones  are  forming  in  the  membranous 
expansion  of  collagenous  tissue,  the  latter  disappears,  being  replaced 
by  them  (p.  359).  It  is  apparently  only  the  soft  and  still  unorgan- 
ized blastema  in  contact  with  the  collagenous  tissue  that  can  be 
converted  directly  into  osseous  tissue.  And  the  probable  reason 
why  the  latter  is  transparent  when  first  formed  in  the  case  of  the 
periosteal  layers,  is,  that  perfect  osseous  tissue  is  at  once  formed ; 
while,  when  formed  in  cartilage,  the  earthy  matter  only  is  first  de- 
posited, and  the  osteine  is  subsequently  formed  and  combined 
with  it. 

In  both  cases,  therefore,  the  cartilage  and  the  collagenous  tissue 
respectively  are  merely  the  matrix  in  which  the  bone  is  formed,  and 
which  disappears  progressively  with  the  formation  of  the  latter. 
Nor  can  the  idea  that  the  same  modified  plasma  may  be  developed 
into  the  collagenous  tissue  on  the  one  hand,  and  the  osseous  on  the 
other,  be  deemed  singular.  Both  contain  the  same  organic  imme- 
diate principle  (osteine) ;  and  the  latter  differs  from  the  former  more 
especially  in  containing  a  greater  amount  of  mineral  constituents. 


GROWTH   AND   REPARATION   OF   BONE.  363 

Oroivth  of  Bone. 

The  long  bones  increase  in  length  principally  at  the  expense 
of  the  cartilage  intervening  between  the  shaft  and  the  epiphyses; 
this  constantly  growing  in  the  longitudinal  direction,  and  giving 
place  to  bone.  But  the  growth  of  the  short  bones,  and  of  the  long 
ones  in  thickness,  has  been  regarded  as  a  difficult  subject  to  com- 
prehend. The  difficulty  has,  however,  arisen  from  the  erroneous 
assumption  that  the  osseous  tissue,  once  developed,  undergoes  very 
slight,  if  an}^,  interstitial  changes.  Tomes  and  De  Morgan  have 
shown  (p.  325)  that  very  active  processes  of  disassimilation  and  re- 
generation occur  in  the  bone-substance.  But,  once  admitting  this 
fact,  there  is  no  more  difficulty  in  understanding  how  a  bone  than 
how  a  muscle  or  any  other  organ  increases  in  size,  whether  in  all 
or  only  in  particular  directions. 

Much  stress  has  been  put  upon  experiments  with  madder  upon 
young  animals,  in  connection  with  this  question.^  This  coloring 
matter  has  a  strong  affinity  for  the  phosphate  of  lime  in  the  bones, 
and  hence,  when  given  in  the  food,  imparts  to  them  a  pink  color ; 
and  it  was  assumed  that  it  combines  with  only  the  osseous  tissue 
which  is  formed  while  the  madder  is  being  taken  by  the  animal. 
It  has,  however,  been  proved  by  Brulle  and  Hugu^ny  that  it  colors 
all  the  osseous  tissue,  even  in  adult  animals,  within  a  certain  dis- 
tance of  the  bloodvessels;  and  that  the  color  remains  in  adult  bones, 
though  it  is  again  removed  in  growing  animals.  Very  little  im- 
portance, therefore,  can  be  attached  to  these  experiments,  except  so 
far  as  that,  when  rightly  interpreted,  they  also  show  (contrary  to 
what  had  been  meanwhile  assumed),  that  a  very  active  metamor- 
phosis is  constantly  going  on  in  the  osseous  tissue,  at  least  till  the 
osseous  system  has  attained  to  its  full  development. 

Reparation  of  Bone. 
Osseous  tissue  is  more  perfectly  regenerated  than  any  other  tissue 
whatever.  This  fact  may  be  associated  with  another — viz.,  that  no 
other  tissue  can,  in  case  of  the  long  bones  especiall}^,  at  all  su|)ply 
the  place  of  the  true  osseous  tissue ;  so  that  nothing  less  than  a 
complete  regeneration  of  the  original  tissue  is  compatible  with  the 
continued  function  of  the  iniured  bone. 


'  In  very  young  animals  a  single  day  serves  to  color  the  entire  substance  of  the 
bones. 


864  THE   TISSUES. 

This  proposition  is  illustrated  in  caries,  where  there  is  merely  a 
loss  of  bone-substance,  and  in  solutions  of  continuity,  or  fractures; 
the  repair  in  both  cases  taking  place  by  the  formation  of  true 
osseous  tissue.  In  the  former  case,  the  new  bone  is  formed  from  a 
blastema  poured  out  by  the  periosteum  of  the  bone;  but  repair 
after  fracture  demands  a  more  particular  description. 

In  most  cases  of  fracture  of  the  long  bones  of  the  lower  animals, 
and  in  those  occurring  in  man  which  are,  for  any  reason,  with  diffi- 
culty kept  in  apposition  during  treatment,  the  formation  of  the  new 
osseous  tissue  is  preceded  by  that  of  cartilage;  and  in  which  the 
osseous  tissue  is  subsequently  developed,  as  are  the  primary  bones 
at  first  (pp.  351 — 8).  This  cartilage  has  been  incorrectly  termed  the 
provisional  callus^  and  has  been  said  by  many  writers  to  be  always 
necessary  for  repair  after  fracture.  Mr.  Paget  has,  however,  shown 
that  this  is  not  the  fact;  and  that  where  the  fractured  extremities 
of  the  bones  are  kept  in  accurate  apposition,  and  at  rest,  it  is  not 
formed  at  all  in  man ;  but  the  new  bone  is  developed  directly  from 
a  blastema,  in  the  exudation  of  which  the  periosteum  doubtless 
performs  the  most  important  part.  Indeed,  all  unbiased  observers 
must  have  been  unable  to  perceive  any  trace  of  provisional  callus 
during  recovery  from  the  most  favorable  cases  of  fracture  of  the 
radius  and  of  the  tibia,  where  it  may  be  felt  whenever  it  actually 
exists. 

In  fracture  of  the  shaft  of  the  long  bones,  the  newly -formed  bone 
at  first  entirely  closes  up  the  medullary  canal ;  thus  forming  a  plug 
entering  and  connecting  the  fractured  extremities.'  But  when  this 
becomes  more  consolidated  and  sufficiently  strong,  the  central  por- 
tions are  reabsorbed,  and  the  medullary  canal  again  extends  through 
the  shaft  of  the  bone  as  before.  It  usually  requires  two  years  or 
more  to  accomplish  this  object;  after  which  the  new  bone-tissue  at 
the  point  of  fracture  is  as  perfect  as  that  of  any  other  part  of  the 
bone,  though  some  sign  of  the  injury  probably  always  remains. 

In  some  cases,  however,  fractures  do  not  unite  by  the  reproduc- 
tion of  bone;  but  the  fractured  extremities  are  united  merely  by 
cartilaginous  tissue  (or  ligament),  and  then  a  sort  of  articulation  is 
found  at  the  point  of  fracture.  This  is  the  case  almost  invariably 
in  fractures  of  the  neck  of  the  thigh-bone  within  the  capsular  liga- 

'  It  is  this  which  Dupuytren,  who  first  used  the  term,  designated  as  the  provi- 
sional callus. 


PATHOLOGICAL   STATES   OF   BONE.  365 

ment,  fracture  of  the  olecranon  process,  and  that  of  the  patella.  It 
is  also  common  in  fracture  of  the  spongy  bones,  and  may  occur  in 
fracture  of  any  bone  under  unfavorable  circumstances;  of  which  a 
want  of  rest  at  the  point  of  fracture  is  the  most  common,  though 
by  no  means  the  only  one.  In  some  cases  a  want  of  plasma  or  of 
plasticity  in  it,  is  the  cause  of  non-union  by  bone. 

The  question  whether  the  plasma  from  which  the  new  osseous 
tissue  is  developed  is  exuded  by  the  periosteum  alone,  or  by  the 
other  soft  parts  also,  is  not  so  important  as  some  authors  seem  to 
have  held.  Obviously  it  can  make  no  difference  whether  it  be 
poured  out  by  the  vessels  of  the  periosteum  alone  (as  it  certainly  is 
in  part),  or  not.  Whencesoever  derived,  however,  it  can  be  organ- 
ized into  bone  only  while  in  contact  with  either  bone  or  periosteum; 
and  hence  the  importance  of  leaving  all  the  spicules  of  bone  in 
place,  in  cases  of  comminuted  fracture,  as  centres  of  ossification  for 
repairing  the  injury — provided  they  are  not  so  detached  as  to  cause 
irritation  as  foreign  bodies. 

Finally,  cases  occur  in  which  entire  bones  have  been  reproduced 
after  removal,  provided  the  periosteum  had  been  preserved.  This 
has  occurred  with  the  lower  jaw-bone,  the  ribs,  the  scapulae,  and  the 
clavicle  in  a  case  known  to  the  author.  A  rudiment  of  bone  has 
sometimes  been  reproduced  in  the  lower  animals,  when  the  whole 
periosteum,  as  well  as  the  bone,  had  been  excised.  [Heine) 

Pathological  Conditions  and  New  Formations  of  Bone. 

The  changes  in  the  chemical  composition  of  bone  in  its  various 
pathological  states  have  already  been  noticed  on  pages  334 — 5. 

I.  Hypertrophy  of  bone  assumes  various  forms,  which  may,  how- 
ever, be  reduced  to  two  classes:  (1),  external  deposits  (hyperostoses), 
formed  chiefly  from  the  periosteum;  and  (2),  internal  deposits,  or 
sclerosis. 

1.  In  regard  to  the  hyperostoses  (exostoses  and  osteophytes), 
Virchow  shows  that  those  of  the  cranium  are  formed  directly  from 
white  fibrous  tissue,  without  the  intervention  of  cartilasre.  Some- 
times  the  new  bone-structure  is  perfectly  normal ;  sometimes  not  so. 
They  appear  from  periostitis,  and  in  arthritis,  syphilis,  &c. 

2.  In  sclerosis  (osteosclerosis),  the  substance  of  the  bone  is  more 
dense  and  harder  than  usual,  and  the  term  ehurnation  has  been  here 
applied.  Here  the  Haversian  rods  are  increased  at  the  expense  of 
the  caucclli  and  the  medullary  canal.  The  lacunar  also  appear  to 
contain  calcareous  salts,  and  are  more  opaque  than  usual. 

II.  Atrophy  of  bone  manifests  itself  in  old  age  (senile  atrophy  of 
the  bones),  and  a  similar  condition  may  occur  in  tuberculosis,  sy- 


366  THE    TISSUES. 

philis,  gout,  rickets,  &c.;  or  from  the  presence  of  aneurism,  abscesses, 
sometimes  from  tumors,  osteophytes,  &c.  The  latter  produce  their 
effect  by  cutting  off  the  supply  of  blood  to  the  bone,  from  compres- 
sion of  its  nutrient  vessels. 

If  the  circulation  through  the  vessels  of  the  medulla  be  inter- 
rupted, a  brownish-yellow  pigment  is  formed  in  the  medullary 
canal,  in  the  areolar  tissue  of  the  marrow.  This  is  most  common 
in  old  persons. 

If  the  circulation  through  the  periosteum  be  interrupted,  it  first 
becomes  atrophied  itself,  as  is  indicated  by  its  shrinking,  or  by  the 
softening  of  its  substance,  together  with  the  loss  of  its  silvery  lus- 
tre, and  its  diminished  adhesion  to  the  bone.  Simultaneously,  also, 
the  bone  becomes  atrophied.  In  some  cases  of  dropsy,  the  bone- 
substance  becomes  lighter,  it  having  undergone  a  partial  resorp- 
tion (as  in  senile  atrophy,  syphilis,  cancerous  cachexia,  paralysis, 
&c.);  in  others,  it  may  disappear  entirely  (as  in  chronic  diseases, 
paralysis,  and  anchylosis). 

III.  Fatty  Degeneration  of  the  Bones  (Osteostearosis)  may  be  re- 
garded as  one  form  of  atrophy.  It  is  most  common  in  old  persons 
affected  with  apoplexy  or  cancer,  and  is  indicated  by  the  presence 
of  one  or  two,  or  even  of  entire  groups  of  fat  globules  in  the  lacu- 
nae, and  sometimes  even  in  the  pores.  (Fig.  196.)  In  the  latter 
case  they  are,  however,  isolated,  wide  apart,  and  far  smaller.  The 
bone  has  a  yellowish  color,  and  a  greasy  feel,  and  a  diminished 
transparency  when  examined  in  thin  plates.  It  has  a  greasy,  lique- 
fied medulla,  and  oil  continues  to  exude  in  spite  of  repeated  boiling. 
This  also  constitutes  one  form  of  mollities  ossium,  while  rachitis  is 
another. 

IV.  Death  of  bone  (necrosis),  occurs  sometimes  from  ostitis,  and 
always  where  the  periosteum  has  been  destroyed.  There  the  lacu- 
nae are  but  little  changed;  while  the  true  osseous  tissue  is  granular 
and  of  a  dark  color. 

V.  Peculiar  conditions  exist  in  osteoporosis,  osteomalacia,  and 
rachitis,  and  the  chemical  changes  in  the  last  disease  have  al- 
ready been  specified  (p.  835).  Osteoporosis  consists  in  a  dilata- 
tion of  the  cancelli,  and  of  the  Haversian  canals.  In  osteopsathyrosis^ 
the  bone  becomes  extremely  brittle  from  atrophy,  with  resorption 
of  the  lamellae  surrounding  the  Haversian  canals. 

VI.  Cancer  and  tubercle  occur  in  bone,  the  former,  however  (espe- 
cially the  medullary  form),  far  the  most  frequently.  The  latter  is 
believed  by  some  to  constitute  the  true  pathological  condition  of 
the  bone  in  morbus  coxarius.  Here  we  find  invading  the  bone 
substance,  the  cancer-cells,  and  the  tubercle- nuclei  (pp.  139  and  117). 

VII.  Pathological  new-formatiuns  of  bone  (true  ossification),  occur 
in  a  variety  of  parts  and  organs,  especially  in  the  periosteum  and 
dura  mater,  and  in  tendons  and  ligaments.  Indeed,  the  possibility 
must  be  admitted  that  true  bone,  distinguished  by  lacunae  and  pores, 
may  be  developed  in  any  part  or  organ  consisting  previously  of 


THE   TEETH  —  DENTINE.  367 

cartilage,  or  of  the  white  fibrous  tissue.  The  ossification,  so  called, 
of  arteries,  and  the  valves  of  the  heart  is  not  actually  so,  since  no 
true  osseous  tissue  is  formed.  It  is  mere  calcification^  and  consists 
merely  in  a  deposit  of  calcareous  salts  (mainly  the  carbonate  and 
phosphate  of  lime)  among  the  histological  elements  of  the  part 
affected.  True  ossification  occurs  in  the  permanent  cartilages  (of 
the  ribs  and  larynx,  and,  rarely,  the  epiglottis),  in  tendons,  in  the 
dura  mater  and  arachnoid  (the  latter  is  very  doubtful) ;  in  the  eye 
( Valentin) ;  in  the  ovary;  in  fibrous  membranes  (the  obturator  mem- 
brane);  in  enchondroma;  in  fibrous  and  carcinomatous  growths, 
and  in  the  lungs.  {Mohr.)  On  the  other  hand,  no  tissue  is  exempt 
from  a  liability  to  calcification,  except  hair,  nails,  and  epidermis. 


CHAPTEE    VIII. 

THE   DENTAL   TISSUES,   AND   THE   TEETH. 

SECTION   I. 
THE   DENTAL   TISSUES. 

The  solid  portion  of  the  teeth  within  which  the  soft  portion,  or 
the  pulp,  is  inclosed,  consists  of  three  distinct  parts  so  far  as  the 
structure  is  concerned. 

1.  The  Dentine,  which  constitutes  by  far  the  greatest  part  of  the 
whole  solid  portion. 

2.  The  Enamel,  a  peculiar  structure  which  covers  the  body  of  the 
tooth,  or  the  part  which  is  free  and  exposed  to  view. 

3.  The  Gementum,  which  is  a  layer  of  true  bone,  covering  the 
fang  and  the  neck  of  the  tooth,  i.  e.  the  part  also  covered  by  the 
gum.  Fig.  230  shows  the  relations  of  these  three.  The  dentine  is 
sometimes  not  covered  at  the  neck  of  the  tooth  by  the  cementum. 

I.  The  Dentine. 

Dentine  is  replaced  by  true  bone  in  the  teeth  of  some  of  the 
lower  animals;  and  its  histological  relationship  to  bone  even  in 
human  teeth,  is  shown  by  the  fact  that  an  Haversian  rod  is  some- 
times seen  in  sections  of  teeth.  In  other  respects,  however,  the 
analogy  is  not  striking  in  man.  A  section  of  dentine  presents 
under  the  microscope  but  two  elements.  (Fig.  231.) 


368 


THE   TISSUES. 


1.  The  solid,  homogeneous  interiubular  substance. 

2.  The  dentinal  tubuli. 

A.  The  interiubular  substance  is  perfectly  structureless,  and  con- 
sists in  great  part  of  the  phosphate  of  lime  in  combination  with  an 


Fig.  230. 


Fig.  231. 

'iiif 


Fig.  230.  Vertical  section  of  human  incisor,  showing  the  general  arrangement  of  its  constituent 
parts.  The  dentine,  the  pulp-cavity,  the  enamel  on  thehody,  and  the  bone  orcementum  on  the  fang, 
are  seen.    a.  Neck  of  the  tooth.     (Magnified  3  diameters.) 

Fig.  231.  Transverse  sections  of  tubules  of  dentine,  showing  their  cavities,  their  walls,  and  the 
intertubular  tissue,  a.  Ordinary  distance  apart,  b.  More  crowded,  c.  Another  view.  Human 
molar.     (Magnified  400  diameters.) 

organic  substance,  doubtless  osteine.'  According  to  Mr.  Tomes,  it 
is  made  up  of  minute  granules  closely  united;  and  these  pass  into 
his  "  granular  layer"  between  the  dentine  and  the  enamel.  (Fig. 
232,  d.) 

Chemical  analysis  of  the  solid  substance  of  dentine  gives  the  fol- 
lowing results.  There  is  more  mineral  matter  in  the  molar  than  in 
the  incisor  teeth. 


Phosphate  of  Lime 

Carbonate  of  Lime  ...... 

Phosphate  of  Magnesia  and  Soda,  and  Common  Salt 
Organic  Substance  (Osteine)    .         .         .         . 


64^ 

H 

28 

100. 


For  it  affords  glutin  on  boiling. 


/ 


THE   DENTINE. 


369 


When  dentine  is  fractured,  it 
presents  a  fibrous  appearance ;  the 
fibres  radiating  from  the  centre  to 
the  circumference  of  the  latter. 
The  tubuli,  of  course,  determine 
their  direction;  thej  being  merely 
columns  of  the  solid  intertubular 
substance. 

B.  The  tuhuli  of  the  dentine 
commence  on  the  internal  surface 
of  the  dentine,  in  contact  with  the 
pulp.  Their  general  direction  is 
upwards  and  outwards  in  the  lower 
'teeth,  downwards  and  outwards  in 
the  upper.  They  average  t^oott 
of  an  inch  in  diameter  at  their  com- 
mencement, but  divide  into  many 
smaller  subdivisions,  separating  at 
acute  angles  from  the  main  trunk, 
and  at  last  terminate  in  the  outer 
surface  of  the  dentine  in  contact 
with  the  enamel  or  the  cementum, 
as  the  case  may  be.  (Fig.  232.) 
The  tubuli  have  a  distinct  and  ap- 
parently very  thick  wall,  occupy- 
ing two  thirds  of  the  diameter  of 
the  whole  tube.  This  appearance 
is,  however,  due  to  the  numerous 
short  curves  in  the  tubes,  about  to 
be  described.  They  are  naturally 
filled  with  a  clear  fluid,  for  the 
nourishment  of  the  teeth,  and 
which  does  not  contain  salts  of 
lime,  as  is  sometimes  stated. — 
Hoppe  finds  that  the  walls  of  the 
tubuli  do  not  contain  gelatine. 

Each    tubule    presents   two   or 

three   large   curvatures   and  very 

many  small  ones — sometimes  even 

2000  within  1  line.  {Retzius.)     Se- 

24 


Fig.  232. 


Dentinal  tubuli  from  the  fang.  a.  Inter- 
nal surface  of  the  dentine,  with  scattered  ca- 
nals, h.  Their  divisions,  c.  Terminations 
with  loops,  d.  Granular  layer,  consisting  of 
small  dentinal  globules  at  the  boundary  of  the 
dentine,  e.  Bone  lacunje,  one  anastomosing 
with  dentinal  canals. — Magnified  350  diame- 
ters.    [Killiker.) 


370 


THE   TISSUES. 


\ 


veral  of  these  occurring  in  a  thin  section  of  dentine  seen  under  the 
microscope,  causes  the  wall  to  appear  shaded  within,  and  thicker 
than  it  actually  is.  (Fig,  231,  a,  b,  c.)  The  branches  of  the  tubuli 
are,  1st.  Principal  divisions,  leaving  the  main  trunk  at  acute  angles: 
and,  being  repeated  two  to  five  times  in  the  thickness  of  the  den- 
tine, amount  to  four,  eight,  or  even  sixteen  in  all.  These  terminate 
in  a  granular  layer  between  the  dentine  and  enamel,  or  between  the 
fibres  of  the  latter,  or  unite  in  pairs  to  form  loops  in  the  dentine. 
2d.  The  anastomosing  branches  are  very  minute  and  numerous,  and 
most  so  in  the  root  of  the  tooth.  These  and  the  primary  divisions 
just  described,  are  seen  in  Fig.  232.  Their  finest  subdivisions  are 
not  more  than  g^j^o  o  ^^  ^^  i^^^h  in  diameter.  Seen  in  dried  sections, 
the  tubuli  appear  black;  being  filled  with  air  merely,  as  is  the  case 
with  the  pores  and  lacunee  of  dried  bone.  Certain  projections  are 
found  in  the  dentine,  called  dentinal  globules  ;^  which  are  bounded 
by  irregular  spaces  called  interglobular  spaces.  The  former  are  found 
mostly  in  the  outer  portion  of  the  dentine,  though  they  also  occur 
in  the  deeper  parts.  They  are  globular  or  capitate,  as  represented 
by  Fig.  233. 

Fig.  233. 


Section  of  dentine,  witli  dentiual  globules,  and  interglobular  spaces  filled  with  air.— Magnified  350 

diameters.     (A'  Hiker.) 

The  interglobular  spaces  are  naturally  filled  by  a  soft  substance, 
like  tooth-cartilage  (osteiue),  and  possessing  a  caualiculatcd  structure, 
like  the  dentine  itself. 

11.  The  Enamel. 
The  enamel  forms  a  layer  completely  investing  the  dentine  of 
the  body  of  the  tooth.     It  is  thickest  on  the  crown  and  the  outside 

'  Hoppe  finds  the  globulojj  to  be  distiuct  cells  with  nuclei. 


ENAMEL. 


871 


and  inside  of  tlie  bodies  of  the  teeth,  and  thinnest  on  the  surfaces 
where  adjoining  teeth  come  into  contact.  It  forms  ridges  on  the 
surface  and  free  borders  of  the  incisor  teeth — of  the  permanent  s^ 
only. 

Enamel  consists  of  solid  fibres  of  a  prismatic  form,  and  marked 
by  transverse  lines,  whose  length  determines  the  thickness  of  the 
enamel.    (Fig.  234,  A.)     Their 

inner  extremity  abuts  upon  the  ^^^'  ^^'^' 

dentine  ;  their  general  direction 
being  nearly  at  right  angles  to 
the  surface  of  the  latter.  In 
form  they  are  hexagonal  prisms, 
slightly  undulating,  and  from 
sAu  to  54^53  of  an  inch  in  dia- 
meter. Hence  the  external  sur- 
face of  the  enamel  presenting 
the  hexagonal  extremities  of  the 
fibres,  resembles  the  simple  sca- 
ly epithelium.  (Fig.  234,  B.)  A 
delicate  membrane  covers  the 
external  surface  of  the  enamel, 
named  "Nasmyth's  membrane,"  from  its  discoverer.  This  is  so 
closely  united  with  the  latter  that  its  existence  can  be  demon- 
strated only  by  the  action  of  hydrochloric  acid  on  the  subjacent 
enamel.  It  is  a  calcified^  simple  membrane,  only  about  tstft  of  an 
inch  thick.  It  is  distinguished,  however,  by  the  great  resistance  it 
offers  to  chemical  reagents,  and  its  consequent  appropriateness  as  a 
protection  to  the  bodies  of  the  teeth.  Boiling  water,  concentrated 
acetic  acid,  hydrochloric  and  sulphuric  acids,  have  no  effect  upon 
it;  and  nitric  acid  only  renders  it  yellow.  Nor  is  it  changed  by 
the  caustic  alkalies. 

The  assertion  by  Ketzius  that  a  similar  membrane  exists  between 
the  inner  surface  of  the  enamel  and  the  dentine,  is  probably  incor- 
rect. 

Though  the  enamel-fibres  are  so  firmly  united,  no  intermediate 
substance  can  be  discovered.  Nor  does  Ktilliker  find  the  canals 
mentioned  by  Todd  and  Bowman  between  the  enamel-fibres.  Clefts 
are,  however,  often  seen  between  them,  especially  in  the  middle  of 


A.  Vertical  section  of  enamel,  showing  the  stria 
of  the  fibres,  b.  Enamel  fibres  seen  endwise. — 
Magnified  3.50  diameters.     (Retziits.) 


'  Dr.  Huxley  maintnins  that  this  is  the  calcified  membrana  prreformativa  of  the 
whole  pulp. —  Quarterly  Journal  of  Microscopic  Science,  vol.  i.  p.  149. 


372  THE   TISSUES. 

the  thickness  of  the  enamel ;  and  the  dentinal  tubes  often  extend  to 
some  distance  between  them. 

.  Chemical  Composition. — Enamel  contains  but  two  parts  of  water 
in  1,000/  and  is  the  hardest  substance  in  the  human  body.  It  can 
hardly  be  touched  by  the  knife,  and  yields  sparks  with  steel.  Ena- 
mel does  not,  like  dentine,  contain  cartilage  (osteine);  but  its  organic 
matter — only  2  to  6.6  per  cent,  of  the  dried  mass — appears  like  a 
membranous  tissue,  after  being  treated  with  acids.  According  to 
Lehmann,  dry  enamel  contains  81  to  88  per  cent,  phosphate  of  lime, 
with  7  or  8  per  cent,  of  carbonate  of  lime;  and  Berzelius  found 
3.2  per  cent,  of  fluoride  of  calcium  in  the  enamel  of  a  human  tooth. 
The  following  is  Von  Bibra's  analysis: — 

Organic  matter        .        .        .        3.59 
Inorganic  matter     .        .        .      96.41 

Cartilage  (?) 3.39 

Fat 0.20 

Phosphate  of  Lime  with  some  Fluoride  of  Calcium     89.82 

Carbonate  of  Lime 4.37 

Phosphate  of  Magnesia 1.34 

Salts 0.88 

In  young  or  developing  teeth,  the  enamel  is  soft,  and  may  be  cut 
with  a  knife;  and  here  the  fibres  may  be  easily  isolated.  They 
also  show  transverse  striee,  somewhat  like  striated  muscular  fibre, 
(Fig.  235,)  especially  after  the  addition  of  hydrochloric  acid ;  but  a 
further  addition  converts  the  fibres  into  transparent  tubes,  and 
finally  entirely  dissolves  the  latter.  It  follows  that  neither  this  acid, 
nor  any  other  agent  that  acts  upon  the  enamel,  should  form  a  part  of 
a  dentifrice,  or  a  wash  for  the  teeth. 

III.  The  Cementum. 
The  cementum  is  a  layer  of  true  osseous  tissue  covering  the  fangs 
and  the  necks  of  the  teeth.  It  commences  where  the  enamel  ter- 
minates, as  a  very  thin  layer,  and  increases  in  thickness  to  the  end 
of  the  fang.  Internally  it  is  very  intimately  united  with  the  den- 
tine, but  without  any  intermediate  substance.  Externally  it  is  very 
closely  surrounded  by  the  periosteum  of  the  alveoli ;  but  it  is  less 
firmly  united  with  the  gum.     It  is  the  softest  of  the  three  dental 

'  Robin  and  Verdeil,  vol.  ii.  p.  115. 


THE   CEMENTUM. 
Fig.  235. 


373 


Isolated  human  enamel  prisms,  after  the  slight  action  of  hydrochloric  acid. — Magnified  300  diameters. 

(KoUiker.) 

tissues,  and  is  chemically  almost  identical  with  bone.    It  consists 

of:— 

Organic  matter  (osteine)     ....  32.24 

Earthy  matter  67.76 


Phosphate  of  Lime  and  Fluoride  of  Calcium    58.73  ^ 


Carbonate  of  Lime     . 

Phosphate  of  Magnesia 

Salts 

Cartilage  (Osteine) 

Fat     .... 


7.22 
.99  ! 


1^67.76 


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24 


Like  bone,  the  ceraentum  consists  of  lacunae  and  pores,  and  the 
intervening  true  osseous  tissue.  It  rarely  contains  Haversian  canals 
and  vessels ;  though  it  has  peculiar  canals  analogous  to  the  tubes 
of  the  dentine,  and  other  abnormal  cavities. 

The  osseous  tissue  may  be  granular,  amorphous,  sometimes  trans- 
versely striated,  or  laminated  like  bone.  The  lacunae  essentially 
resemble  those  of  bone;  but  present  great  varieties  of  number, 
form,  and  size  (54VTT  to  even  ^^^  of  an  inch).  The  pores  are  unu- 
sually numerous  and  long  (^^^  of  an  inch) ;  and  often  resemble 
feathers  and  brushes.     (Fig.  232,  e.) 


374 


THE   TISSUES. 


Fig-  236.  The  thinnest  part  of  the  cemen- 

tum  contains  no  lacunae,  they  ge- 
nerally commencing  about  the  mid- 
dle of  the  fang,  where  they  are 
scattered  and  solitary ;  and  becom- 
ing more  numerous,  and  having 
their  lacunae  freely  communicating 
towards  its  extremity.  (Fig.  230.) 
The  thick  cement  occurring 
upon  old  teeth,  presents  immense 
numbers  of  lacunoe,  and  very  com- 
monly, Haversian  canals  also,  as 
seen  in  Fig.  236.  In  hyperostoses 
of  the  teeth,  one,  three,  or  more 
canals  are  sometimes  seen  enter- 
ing the  cementum  from  without, 
branching  two  or  three  times,  and 
then  terminating  in  blind  extremi- 
ties. 
Cavities  resembling  the  dentinal  tubes  are  also  sometimes  found 
in  the  cementum;  and  which  frequently  communicate  with  the  end 
of  the  tubuli  on  the  one  hand,  and  the  pores  of  the  osseous  lacunae 
on  the  other.  Other  cavities  still  have  been  described,  but  they  are 
evidently  pathological. 

Remarks. — Thus  it  appears  that  the  dentinal  tubuli,  and  especially 
the  finest  subdivisions,  are  homologous  with  the  pores  of  bone.  In 
the  latter  the  lacunar  are  added  as  if  expansions  of  the  pores,  to 
insure  a  freer  circulation  of  the  plasma  from  which  the  bone  is 
nourished;  while  in  teeth  such  a  development  would  not  consist 
with  the  degree  of  solidity  and  strength  required  in  them  as  organs 
of  mastication. 


Cement  and  dentine  of  the  root  of  an  old 
human  tooth,  a.  Pulp  cavity.  6.  Dentine. 
c.  Cement,  with  lacuuie.  e.  Haversian  canals. 
[KMiker.) 


SECTION   II. 
THE    STRUCTURE    OF   THE   TEETH, 

The  teeth  consist  oi— first,  the  external  solid  (cortical)  portion; 
and,  secondly,  the  internal  soft  portion,  the  pulp.  The  teeth  are  also 
in  contact  with — first,  the  gum;  and,  secondly,  the  periosteum  of  the 
alveoli  (the  cavities  in  which  the  teeth  are  inserted). 

1.  The  cortical  portion  of  the  teeth  consists  of  dentine,  enamel, 
and  cementum,  as  already  shown  in  Fig.  230. 


STRUCTURE   OF   THE   TEETIT.  375 

2.  The  dental  ;m?/)  rises  from  the  periosteum  at  the  bottom  of  the 
alveolus,  enters  the  fang,  and  fills  the  cavity  of  the  tooth,  and  the 
dentinal  canals;  being  everywhere  in  close  adherence  to  the  inner 
surface  of  the  dentine.  It  is  a  reddish,  soft,  very  vascular  and  nerv- 
ous substance;  and  consists  of  mere  rudimentary  collagenous  tissue, 
inclosing  many  dispersed,  round,  and  elongated  nuclei,  and  a  fluid 
substance,  with  the  vessels  and  nerves.  It  is  invested  externally  by 
a  basement-membrane,  underneath  which  is  a  layer  g^^  to  3  Jg  of 
an  inch  thick,  composed  of  many  series  of  cells,  j-q^-q  of  an  inch 
long,  and  45'g^  of  an  inch  broad,  arranged  perpendicularly  to  the 
surface  of  the  pulp  like  a  conoidal  epithelium — the  formative  cells 
of  the  dentine^  to  be  described  further  on. 

The  vessels  of  the  pulp  are  very  numerous.  Three  to  ten  small 
arteries  enter  the  pulp  of  a  simple  tooth,  and  form  both  internally 
and  upon  its  surface  a  loose  plexus  of  capillaries,  g^'^u  to  ^d'ou  of 
an  inch  in  diameter.     There  are  no  lymphatic  vessels.  {Kolliker^ 

The  nerves  of  the  pulp  are  extremely  abundant.  Into  every  fang 
enters  a  large  trunk  {^\-q  to  g^jj  of  an  inch),  and  six  or  more  fine 
branches  (of  ya'cu  to  gig  of  an  inch),  containing  fibres  of  ja^uu  ^o 
'f'i^'5  of  an  inch.  Kolliker  inclines  to  the  opinion  that  they  ter- 
minate in  loops ;  but  this  is  not  yet  demonstrated. 

3.  The  gum  (gingiva)  is  the  portion  of  the  mucous  membrane  of 
the  mouth  uniting  the  necks  of  the  teeth  and  the  alveolar  margins 
of  the  jaw-bones.  It  is  pale  red,  and  rather  soft,  though  feeling  firm 
because  resting  on  the  bone  and  teeth.  Upon  the  teeth  it  is  |  to 
i|-  line  thick,  and  has  papillie  of  g'g  to  ^'^  of  an  inch  long — in  old 
people  even  y'^  of  an  inch.  Like  the  papillae  fili formes  of  the  tongue, 
they  are  covered  with  secondary  papillse,  and  a  conoidal  epithelium, 
which  between  the  papillaB  is  ^^-^  to  3  J-^  of  an  inch  thick.  Some- 
times on  its  upper  portions  there  are  rounded  depressions  in  it,  j'^ 
to  ^  of  an  inch  in  diameter,  with  cells  more  cornified,  and  which 
may  be  mistaken  for  glands. 

4.  The  periosteum  of  the  alveolus  is  very  intimately  connected 
with  the  fangs  of  the  teeth,  having  the  same  structure  as  au}^  other 
periosteum,  except  that  it  is  softer,  contains  no  elastic  tissue,  and 
possesses  an  abundant  nervous  network  containing  many  of  the 
large  nerve-fibres. 

Properties  and  Uses  of  the  Teeth. 
The  principal  function  of  the  teeth,  viz.  as  masticatory  organs, 
is  well  understood.     They  are  also  subservient  to  speech. 


376  THE   TISSUES. 

The  teeth  are  affected  by  contact,  by  heat,  cold,  and  chemical 
agents ;  their  sensibility  arising  from  the  nerves  in  their  pulp.  It 
is  quite  delicate  on  the  masticatory  surfaces,  where  the  smallest 
foreign  bodies — as  small  grains  of  sand,  &c. — are  at  once  perceived 
when  those  surfaces  are  opposed  to  each  other.  It  may  also  in  dis- 
ease become  excessively  acute. 

Slight  mechanical  influences  can  only  act  by  the  vibration  which 
they  produce.  Yet  the  teeth  have  a  certain  sense  of  locality,  since 
we  can  distinguish  whether  they  are  touched  internally  or  exter- 
nally, above  or  below,  on  the  right  or  the  left  side.  Acids  cannot 
penetrate  the  enamel,  though  it  is  not  impermeable;  since  the  nerves 
of  the  pulp  are  not  affected  by  them  while  the  enamel  is  entire,  but 
are  so  at  once  when,  as  in  the  incisors,  the  dentine  is  exposed. 
Nasmyth's  membrane  is  doubtless  still  more  impenetrable  than  the 
enamel  itself. 

Development  of  the  Teeth. 

The  first  set  (deciduous  or  milk-teeth)  contains  twenty,  and  the 
second  (permanent  teeth)  thirty-two  teeth.  Each  tooth,  during  its 
development,  presents  a  papillary,  a  follicular,  a  saccular,  and  finally 
its  eruptive  state. 

The  development  of  the  milk-teeth  commences  in  the  sixth 
week  of  foetal  life ;  twenty  dental  papillae  making  their  appearance 
from  this  period  up  to  the  tenth  week,  in  a  groove  called  the  dental 
groove.  Next,  partitions  are  formed  between  the  papillie,  and  each 
then  lies  in  a  special  follicle  or  cavity ;  and  thus  the  papillary  has 
merged  into  the  following  stage.  During  the  fourth  month  these 
cavities  contract,  and  finally  close  up  completely,  the  papillae  within 
them  at  the  same  time  assuming  the  forms  of  the  future  teeth ;  and 
thus  the  saccular  stage  is  arrived  at.  A  little  cavity  is,  however,  at 
the  same  time  prolonged  from  each  closed  tooth-sac;  these  being 
the  "reserve-sacs"  in  which,  during  the  fifth  month,  are  developed 
the  pulps  of  the  twenty  anterior  teeth  of  the  second  set.  These 
reserve-sacs,  however,  gradually  retract  backwards,  and  fall  into 
hollows  in  the  jaw-bones;  and  lie  at  considerable  depth  in  the  latter 
by  the  time  the  first  set  make  their  appearance — by  having  attained 
to  the  final  or  eruptive  stage. 

The  four  stages  just  mentioned,  and  the  relations  of  the  "reserve- 
sacs,"  are  shown  by  Fig.  '237.  The  last  are  produced  at  their  apices 
into  a  solid  cord,  which  has  erroneously  been  called  the  guhernacu- 
lum  dentis,  or  guiding  cord  for  the  permanent  teeth  in  their  eruption. 


DEVELOPMENT   OF   THE   TEETH.  377 

Fig.  237. 


Formation  of  a  temporary  and  its  corresponding  permanent  tooth,  in  a  sac  of  the  mncous  mem- 
brane, a  to  d.  Papillary  stage ;  e  to  g.  Follicular  do.  ;  h  to  m.  Saccular,  do.  ;  n,  o.  Eruptive  stage  ; 
p  to  t.  Falling  out  of  first  set. 

From  the  manner  in  whicli  tlie  primary  tooth-sacs  are  formed — 
i.  e.  by  elevations  of  the  mucous  membrane  around  the  papillae,  as 
shown  in  Fig,  237,  d,  e — it  follow^  that  the  papilla,  even  after  attain- 
ing to  the  form  of  the  body  of  the  future  tooth, 
does  not  cause  the  layer  covering  it,  of  the  ori- 
ginal mucous  membrane  of  the  mouth,  to  come 
into  contact  with  the  layer  which  has  closed 
over  it;  and  therefore  a  space  is  left  between 
these  two  layers — the  cavity  in  which  the  ena- 
mel is  formed  (Fig.  238,  B)  from  cells  (the  ena- 
mel pulp)  contained  in  it. 

The  general  account  of  the  development  of 
the  teeth  is  as  follows :  1.  A  thin  layer  of  den- 
tine is  formed  from  the  vessels  in  the  pulp,  and 
which  incloses  the  latter  like  a  cap.  This  is  fol- 
lowed by  other  layers  within  each  other,  the  pulp  itself  meanwhile 
contracting.  2.  The  enamel  is  formed  from  the  cells  in  the  enamel- 
cavity  ;  a  thin  layer  being  at  first  adherent  to  the  outer  layer  of 
dentine,  and  which  is  followed  by  others  till  the  requisite  thickness 
is  acquired,  the  enamel-pulp  meantime  gradually  disappearing.  3. 
The  body  of  the  tooth  thus  being  developed,  the  formation  of  the 
fang  next  takes  place ;  the  pulp  of  the  dentine  now  extending  into 
the  alveolus,  and  dividing  into  two  or  three  processes  if  the  fang  is 


A.  The  cavity  containing 
the  pulp,  and  the  dentine 
Tvhen  formed.  B.  Closed 
sac  in  which  the  enamel 
is  formed. 


178 


THE   TISSUES. 


to  be  double  or  triple.  The  development  of  the  fang  from  the  den- 
tinal pulp  is  precisely  like  that  of  the  dentine  in  the  body  just  de- 
scribed ;  and  this  process  elevates  the  latter  through  the  gum,  and 
thus  the  eruption  of  the  tooth  takes  place.  The  enamel,  of  course, 
covers  the  body  only,  since  the  enamel-sac  extended  only  over  the 
latter.  4.  Finally,  as  the  alveoli  close  around  the  necks  of  the  teeth 
during  their  eruption,  and  afterwards  more  completely  around  the 
fangs,  the  vessels  of  the  periosteum  of  the  alveoli  deposit  a  plasma 
from  which  the  cementum  {tooth-hone)  is  formed;  and  which  be- 
comes adherent  to  the  dentine,  and  forms  a  layer  becoming  thicker 
as  it  approaches  the  apex  of  the  fang,  as  before  described  (p.  374). 

The  explanation  of  the  mmutioe  of  this  process  requires  a  know- 
ledge of  the  minute  structure  of  the  dentinal  pulp,  and  the  enamel- 
sac  and  its  contents.  And  the  following  statement  is  deemed  the 
most  accurate,  in  its  details,  of  the  various  accounts  given  by  dif- 
ferent authors: — 

1.  The  dentinal  pulp  precisely  resembles,  in  size  and  form,  the 
body  of  the  tooth  to  be  developed  from  it,  consisting  of  an  internal 
portion  rich  in  vessels,  and  an  external  portion  which  is  entirely 


Fig.  239. 


^ 


V? 


A.  Tooth-sac  of  tho  second  incisor  of  an  eight  months  fojtus,  soon  on  the  broad  surfaco.  a.  Dental 
sac.  b.  Enamol-pnlp.  c.  Eiiamol-inpnilirano.  d.  Eniimol.  e.  Dontiue.  /.  Dentinal  cells,  h.  Dental 
pulp.  i.  Free  edge  of  tlio  enam(>l-organ. — H  First  incisor  of  the  same  embryo,  seen  on  the  narrow- 
surface ;  letters  as  before,  a.  Dentinal  cap  in  toto.  k.  Nerves  and  vessels  of  the  pulp. — Magnified 
7  diameters.  (KVUiker.) 


DEVELOPMENT   OF   THE   TEETH. 


379 


Fig.  240. 


destitute  of  them ;  and  is  bounded  by  a  simple  membrane — the  mem- 
hrana  prcpformativa.  {Raschkoiv.)  (Fig.  239.)  Beneath  this  is  a  layer 
of  elongated  cells  (.^^g  to  5 Jg  of  an  inch  long,  by  g^'g^j  to  2g'5g  of 
an  inch  wide),  with  vesicular  nuclei  and  distinct  single  or  double 
nucleoli,  arranged  like  an  epithelium,  though  not  so  sharply  defined 
internally ;  and  next  is  the  paren- 
chyma of  the  pulp,  consisting  of 
a  sort  of  rudimentary  collagenous 
tissue,  with  many  rounded  or  elon- 
gated nuclei,  and  the  vessels.  (Fig. 
240.)  The  latter  become  very  nu- 
merous at  the  period  when  the  den- 
tine begins  to  be  formed,  the  most 
numerous  perpendicular  loops  of 

capillaries,  5o'ot>  ^^  ^^  ^^^^^  i'^  ^^" 
ameter,  being  in  contiguity  with 
the  surface  of  the  dentine.  The 
nerves  are  developed  later.  Their 
distribution,  as  well  as  that  of  the 
vessels,  in  the  pulp  of  the  perfect 
tooth,  has  already  been  described 
(p.  375). 

It  is  from  the  epithelium-like 
layer  of  cells  that  the  dentine  is  formed;  and  the  former  seems  to 
maintain  a  constant  thickness  by  the  elongation  of  the  original  cells 
internally  (while  the  dentine  is  formed  externally),  accompanied  by 
a  continual  multiplication  of  their  nuclei.  The  parenchyma  of  the 
pulp,  therefore,  progressively  diminishes  as  the  dentine  increases ; 
the  latter  being  formed  in  concentric  layers  from  without  inwards, 
like  the  lamellae  of  the  Haversian  rods  of  bone  (p.  356). 

It  appears  that  the  cells  just  described  become  the  solid  dentine 
by  the  gradual  reception  of  calcareous  salts.  The  largest  tubuli 
are  probably  the  remaining  unossified  portions  of  the  cavity  of  the 
cells,  and  are  hence  analogous  to  the  lacunas  of  bone.  The  divi- 
sions of  the  tubuli  may  result  from  a  longitudinal  division  of  the 
cells,  or  from  a  single  cell  coalescing  with  two  of  its  predecessors. 
The  finest  lateral  branches  appear  to  be  of  secondary  origin,  and 
probably  result  from  resorption  of  already  formed  dentine,  like  the 
pores  of  bone  (p.  354). 

During  the  ossification  of  the  dentine,  and  while  recently  formed 


Surface  of  the  dentinal  pulp  of  a  neTr-bom 
infant,  a.  Dentinal  cells,  b.  Their  appendages, 
c.  Vascular  part  of  the  pulp. — Magnified  300 
diameters.  (Kolliker.) 


380 


THE   TISSUES, 


and  slightly  hardened,  the  whole  appears  to  consist  of  isolated  glo- 
bules. Some  of  them  are  also  visible  at  later  periods,  the  spaces 
between  them  being  the  interglobular  spaces  already  described  (p. 
370),  Usually,  however,  these  spaces  are  filled  by  a  deposition  of 
dentine  also,  so  that  the  latter  becomes  quite  homogeneous  and  clear. 
2.  The  enamel-cavity  is  a  closed  sac,  aod  contains  the  enamel-pulp, 
which  is  applied  to  the  dentinal  pulp  like  a  cap,  and  presents  a  pe- 
culiar structure.  1.  Its  mass  consists 
at  first  of  anastomosing  stellate  cells 
(Fig,  239),  containing  a  great  quantity 
of  fluid,  rich  in  albumen  (and  mucus, 
KoUiker),  in  its  meshes.  It  forms  a 
layer  ^'g  to  Jg  of  an  inch  thick  in  the 
foetus  of  five  or  six  months,  and  but 
?V  ^^  e'o  of  an  inch  at  birth ;  when  it 
contains  vessels  in  its  outer  third,  and 
its  network  is  metamorphosed  into 
white  fibrous  tissue,  2,  On  the  inside, 
however,  of  this  spongy  tissue  lies  a 
true  cylindrical  (conoidal)  epithelium 
in  contact  with  the  dentinal  pulp.  This 
is  incorrectly  termed  the  enamel-mem- 
brane (membrana  adamantina?,  Rasch- 
how).  Its  cells  are  y^'c^  of  an  inch  in 
length,  and  g^'^g  of  an  inch  in  breadth, 
are  finely  granular,  and  their  nuclei 
are  frequently  situated  at  their  extre- 
mities. 

The  enamel-yiJres  are  formed  by  the 
complete  and  direct  ossification  of  the 
cells  just  mentioned,  without  a  pre- 
vious deposit  of  calcareous  matter  in  a 
granular  form.  {KoUiker.)  (Fig,  241.) 
The  first  layer  of  enamel  is  deposited 
upon  the  outermost  layer  of  dentine, 
already  described,  and  the  successive 
ones  are  formed  externally  to  this,  till 
the  required  thickness  is  obtained. 
Meantime  the  epithelial  layer  con- 
stantly remains  of  the  same  thickness 


Formation  of  enamel,  h.  Primary 
cells  suspended  in  fluid  blastema,  j/,  t. 
The  same  more  fully  developed,  and  be- 
come angular.  J.  The  same  becoming 
prismatic,  k.  Tlie  nucleus  disappear- 
ing. I.  The  modified  prismatic  cells 
filled  with  calcareous  salts,  forming  the 
fibres  of  enamel. 


ERUPTION   OF   THE   TEETH.  381 

by  a  progressive  development,  while  the  spongy  tissue  proportion- 
ately diminishes,  and  at  last  entirely  disappears,  together  with  the 
epithelial  cells ;  when  the  development  of  enamel  is  completed. 

Thus  the  membrana  praeformativa  (p.  379)  has  an  epithelial  layer 
upon  both  of  its  surfaces;  the  dentine  being  developed  from  the 
inner  one,  while  the  enamel  is  formed  from  the  outer  one;  the  ves- 
sels affording  the  plasma  being  on  the  distal  side  of  the  epithelial 
layer,  from  the  membrana  proeformativa,  in  both  cases, 

3.  The  cementum  is  believed  by  Kolliker  to  be  formed  by  the 
"portions  of  the  dental  sac  lying  between  the  pulp  and  the  enamel- 
organ."  We  consider  that  the  sac  merely  embraces  the  enamel- 
organ,  and  isolates  it  from  the  dental  pulp;  while  the  latter  affords 
the  epithelial  layer  whence  the  dentine  is  developed.  Another  source 
of  the  cementum  must  therefore  be  sought,  and  none  is  more  pro- 
bable than  the  periosteum  of  the  alveoli.  After  the  body  of  the 
tooth  is  completed,  the  pulp  elongates  towards  the  bottom  of  the 
alveolus,  and  thus  the  fang  is  developed  from  it,  the  body  at  the 
same  time  penetrating  through  the  gum  in  the  opposite  direction. 
Kolliker  states  that  the  sac  elongates  at  the  same  time  with  the 
pulp,  and  thinks  that  its  inner  surface  affords  a  blastema  whence  the 
cementum  is  formed  and  deposited  on  the  outer  surface  of  the  den- 
tine of  the  fang. 

It  is  difl&cult  to  account  for  the  development  of  Nasmyth's  mem- 
brane. On  the  supposition,  however,  that  the  membrana  prseforma- 
tiva  originally  lines  the  whole  of  the  enamel-cavity,  it  may  be 
produced  by  calcification  of  the  membrane,  gluing  together  and 
protecting  the  outer  ends  of  the  prisms  of  the  enamel. 

The  permanent  teeth  are  also  developed  in  the  manner  just  de- 
scribed, from  the  secondary  pulps  mentioned  on  page  376,  1. 

The  two  sets  of  teeth  appear  at  the  following  ages: — 

I.   MILK-TEETH. 

Four  central  incisors  (the  lower  first),  7th  month. 
Lateral  incisors  (lower  first),  7th  to  10th         " 
Anterior  molars,  12th  to  13th  " 

Canine  teeth,  14th  to  20th  " 

Posterior  molars,  18th  to  36th  " 


382 


THE   TISSUES. 

II. 

PEEMANENT  TEETH. 

Central  incisors   . 

8  years. 

Lateral       " 

.       9      " 

First  bicuspid 

.     10      " 

Second     " 

.     11      " 

Canines 

.     12    to  12 A-  years 

Second  molars 

.     12|  to  U        " 

Third 

.     17    to  19 

Growth  of  the  Teeth. 

The  enamel  does  not  increase  in  amount  after  the  eruption  of  the 
teeth.  It  is,  however,  susceptible  of  some  molecular  changes,  as  its 
diseases  indicate — especially  caries.  The  latter  is  true  of  the  den- 
tine also,  and  the  cementum ;  both  of  which,  moreover,  become 
thicker  after  the  eruption  of  the  teeth.  Indeed,  in  old  persons  the 
pulp  has  sometimes  entirely  disappeared,  and  its  cavity  been  filled 
with  an  imperfect  dentine;  and  the  cementum  amounts  to  an  exos- 
tosis (p.  374).  The  fissures  between  the  enamel-prisms,  the  dentinal 
tubuli,  and  the  lacuna?  and  pores  of  the  cementum — all  during  life 
contain  a  nutritive  fluid,  and  permit  of  nutritive  changes.  Since, 
however,  perfect  dentine  is  not  colored  by  madder  when  an  animal 
is  fed  with  it,  it  is  probable  that  these  changes  are  far  less  active 
than  in  the  bones.  In  case  of  caries  threatening  an  exposure  of  the 
pulp  of  the  teeth,  the  dentine  very  often  becomes  thicker  within, 
and  opposite  the  carious  portion ;  the  new  dentine  being  formed  to 
protect  the  pulp. 

Any  portion  of  a  tooth  being  once  removed,  is  never  reproduced ; 
nor  is  the  loss  at  all  repaired. 

A  third  dentition  sometimes  occurs  late  in  life,  though  the  teeth 
are  imperfectly  developed  and  few  in  number.  A  tooth  extracted 
and  at  once  replaced,  may  become  firm  again  at  the  end  of  some 
months  (fifteen  in  one  case). 

Pathological  States  of  the  Teeth. 

1,  Hypertrophy  of  the  cement  (exostosis),  deposits  of  dentine 
projecting  into  the  pulp  cavity,  and  ossification  of  the  pulp  itself, 
are  very  common  results  of  chronic  inflammation  of  the  perios- 
teum and  the  pulp.  In  the  first,  the  pores  become  dilated,  so  as  to 
form  Haversian  canals.  (  Wedl.) 

2.  A  partial  disappearance  of  the  fang  is  quite  common.  The 
whole  fang  sometimes  becomes  transparent  like  horn. 


MUSCULAR   OR   CONTRACTILE   TISSUE.  883 

3.  Necrosis  occurs  where  the  periosteum  has  been  removed,  or  the 
pulp  has  died.  Here  the  tooth  becomes  rough,  dark,  and  even 
black,  and  at  length  falls  out. 

4.  Caries  of  the  teeth,  as  in  bone,  is  a  gradual  loss  of  substance. 
Its  cause  is  not  well  understood.  Since  it  always  commences  on 
the  exterior,  the  fluids  of  the  mouth  are  supposed  to  have  an  influ- 
ence in  producing  it.  There  must,  however,  be  a  coincident  putre- 
factive decomposition  of  the  organic  elements  of  the  tooth,  Avhich 
becomes  covered  with  infusoria  and  fungi.  {KoUiker.)  Indeed, 
Ficinus  thinks  the  latter  are  the  principal  cause  of  caries,  since  it 
usually  commences  in  the  cracks  and  pits  of  the  enamel,  where  un- 
disturbed opportunity  is  given  for  these  organisms  to  develop. 
The  discolored  spots  on  the  enamel  first  lose  their  salts,  and  then 
break  up  into  angular  pieces.  Next  the  dentine  becomes  soft, 
yielding  not  more  than  ten  per  cent,  of  ash  {Ficinvs)^  and  then  de- 
composed, and  the  dentinal  tubuli  become  filled  with  the  fluids  pro- 
ceeding from  its  decomposition;  and  which, reaching  the  pulp,  may 
produce  pain.  Carious  teeth  contain  an  excess  of  carbonate  of 
lime.  (Marchand.) 

5.  In  jaundice  the  teeth  often  become  yellow,  and  in  asphyxia, 
red:  the  dentinal  tubuli  being  penetrated  by  the  coloring  matter  of 
the  bile,  and  the  blood,  respectively.  In  rickets,  the  teeth  are  not 
affected  (p.  SSi).  The  mucus  upon  the  teeth  always  contains  fungi; 
and,  on  accumulating,  it  hardens  and  constitutes  the  tartar  of  the 
teeth.  This  consists  of  earthy  phosphates,  79;  mucus,  12.5;  ptya- 
line,  1,  and  organic  matters  soluble  in  hydrochloric  acid,  7.5.  [Berze- 
lilts.) 

6.  Finally,  teeth  are  sometimes  developed  in  abnormal  situations, 
as  in  ovarian  cysts. 


CHAPTEE   IX. 

MUSCULAR   (contractile)  TISSUE,    AND   THE   MUSCLES. 

SECTION  I. 
MUSCULAR   OR   GONXRACTILE   TISSUE. 

Muscular  tissue  has  recently  been  regarded  as  presenting  three 
varieties:  the  elongated  or  fusiform  contractile  cell;  the  smooth 
or  non-striated  muscular  fibre,  and  the  striated  muscular  fibre. 
Kolliker  has,  however,  shown  that  the  elongated,  contractile  cell 
and  the  smooth  muscular  fibre  are  histologically  identical.  He, 
therefore,  includes  both  these  under  the  name  of  "contractile  (or 


384 


THE   TISSUES. 


muscular)  fibre-cells;"  since  in  case  of  botli,  cells  are  found,  more 
or  less  elongated  into  the  form  of  fibres.  Only  two  varieties,  there- 
fore, of  muscular  tissue  need  be  recognized;  viz.,  the  fibre-cells 
just  mentioned,  and  the  striated  muscular  fibre. 

I.  The  Contractile,  or  Muscular,  Fibre-cells. 

The  larger  fibre-cells  have  generally  been  named  smooth,  or  non- 
striated,  muscular  fibres,  and  have  been  described  as  jointed  fibres, 
presenting  nodosities,  as  represented  in  Fig.  2-12.  This  is,  however, 
their  appearance,  very  nearly,  when  acted  upon  by  water.  An  ac- 
curate description  of  them  was  first  given  by  Kolliker. 

The  muscular  fibre-cells  are  from  g^^  to  3^5  of  an  inch  long,  by 
STToo  to  4o'oo  of  ^^  i'^ch  broad;  and  are  composed  of  a  soft,  nearly 
homogeneous  light-yellow  substance.  The  nuclei  are  visible  only 
when  acted  upon  by  acetic  acid,  and  are  usually  long  and  staff-like, 
as  seen  in  Fig.  243,  which  also  shows  the  usual  long  and  slender 

form  of  the  cells.     Very  sel- 


Fig.  242. 


Fig.  243. 


dom  a  nucleolus  exists  in  the 
nucleus,  and  the  latter  is  al- 
ways in  the  middle  of  the 
fibrQ.  The  substance  of  the 
cell  sometimes  exhibits  pale, 
dark  granules,  partially  ar- 
ranged in  rows  parallel  to 
the  axis  of  the  cell;  but,  in 
other  respects,  the  cell,  like 
the  nucleus,  is  homogeneous 
and  hyaline. 

It  is,  however,  doubtful  if 
any  cell-memhrane  exists. — 
Kolliker  thinks  he  has  seen 
it  in  some  individual  fibres; 
but  Lehmann  cannot  demon- 
strate its  existence  chemi- 
cally, and  concludes  that 
these  fibres   are    never  in- 


Flg.  242.  A.  A  non-striatod  muscular  fibre  from  the 
urinary  bladder.  Two  of  the  nuclei  are  seen.  B.  A 
uon-striated  muHCular  fil)ro  from  the  stomach.  The 
diameter  of  this  and  the  preceding  fibre,  midway  be- 
tween the  nuclei,  was  1-4750  of  an  inch.     (Magnified  600     cloSCd  by  a  trUC  myolcmma. 

^'T'llVv    -r  n      .  M  ,      «,      r  ^llOUld    his 

Fig.  24.3.  Fusiform  cells  of  smooth  muscular  fibre  from 

the  renal  vein  of  man.     a.  Two  colls  in  their  natural 

state,  one  of  them  showing  the  stalf-sliaped  nucleus,     h. 

K   cell   treated  with  acetic  acid,  with  a   nucleus,  a,  c, 

brought  strongly  Into  view. 


opinion  be  de- 
monstrated to  be  correct,  the 
term  fihre-cell  must  be  again 
replaced  hy fibre  merely.  We 


MUSCULAR   FIBRE-CELLS. 
Fig.  244. 


185 


Fig.  246. 


Human  muscular  fibre-colls  from  the  innermost 
layer  of  tho  axillary  artery:  a,  without,  b,  with 
acetic  acid.  a.  Nucleus  of  the  fibre. — Magnified  350 
diameters.     (KiJlUker.) 

shall,  therefore,  quite  as  frequently 
term  them  smooth  muscular  fibres. 
The  more  common  forms  of  the 
fibre-cells  have  been  mentioned. 
But  in  the  walls  of  the  bloodvessels 
(Fig.  244),  they  are  so  much  less 
elong-ated  as  sometimes  to  have  been 

O 

mistaken  in  the  smallest,  for  epithe- 
lial cells ;  while  in  the  alimentary 
canal,  uterus,  &c.,  they 
become  what  have  long 
been  called  the  non-stri- 
ated muscular  fibres  of 
these  organs.  The  lar- 
gest of  all  appear  in  the 
impregnated  uterus ;  and 
Fig.  245  shows  one  of  the 
long  cells  as  compared 
with  those  of  Fig.  244. 
Rarely,  also,  the  cells  are 
in  the  form  of  elongated, 
quadrangular,  or  club- 
shaped  plates,  with  fring- 
ed margins.  (Fig.  244,  a, 
and  245,  6,  c.) 

Muscular  fibre-cell  from  the  fibrous  investment  of 
the  spleen  of  tho  dog. — Magnified  300  diamcterti. 
(KoUiker.) 

25 


386 


THE   TISSUES. 


When  the  muscular  fibre-cells  exist  in  abundance  in  an  organ 
(e.  g.  the  alimentary  canal,  bladder,  &c.),  they  are  (1).  Collected  into 
little  bundles  or  fasciculi,  whicb  are  invested  by  a  very  delicate 
layer  of  areolar  tissue — a  kind  of  perimysium  ;  and  which  also  in- 
closes a  peculiar  fluid  lying  among,  and  bathing  the  cells.  (2). 
The  fasciculi  thus  invested,  are  interwoven  to  form  the  required 
mass  or  thickness  in  the  part  or  organ.  (3).  Bloodvessels  are  also 
sent  in  among  the  fasciculi  to  a  considerable  amount  (Fig.  247); 

Fig.  247. 


Bloodvessels  of  the  smooth  muscles  of  the  intestines. — Magnified  i5  diameters.     (KiUiker.) 

while  but  a  relatively  small  number  of  nerves  is  distributed  to  this 
tissue. 

Chemical  Composition  of  Muscular  Fibre-  Cells. 

1.  The,  fluid  which  bathes  the  fibre-cells  in  the  fasciculi  is  identi- 
cal with  that  contained  within  the  myolemma  of  the  striated  mus- 
cular fibre ;  and  will  be  spoken  of  further  on  in  this  section  under 
the  name  of  the  muscular  juice  (p.  395). 

2.  The  demi-solid  and  most  important  element  of  the  fibre-cells 
is  musculine  (p.  98),  also  called  muscular  fibrine,  and  named  syyi- 
tonin  by  Lehmann.  But  since  this  also  forms  the  solid  substance 
of  the  fibrillae  of  the  striated  muscular  fibre,  it  will  be  described 
on  a  subsequent  page  (396). 


MUSCULAR   FIBRE-CELLS.  3,87 

Distribution  of  Muscular  Fibre- Cells. 
The  smallest  forms  of  these  cells  are  found  in  the  walls  of  the 
smallest  arteries  and  veins,  and  the  larger  lymphatics.  The  follow- 
ing general  account  of  the  distribution  of  all  their  forms  is  from 
Kulliker.  It  should,  however,  be  premised  that  this  kind  of  mus- 
cular tissue  never  forms  isolated  muscles  in  the  human  body.  The 
fibres  are  either  scattered  in  the  areolar  tissue,  or  form  membranous 
expansions — as  the  muscular  layer  of  the  bladder  and  alimentary 
canal ;  and  in  either  case  the  fasciculi  are  either  parallel,  or  woven 
into  a  network. 

1.  In  the  alimentary  canal,  these  fibre-cells  form  the  muscular 
coat  (tunica  musculosa),  from  the  lower  half  of  the  oesophagus, 
where  striated  fibres  are  mixed  with  them,  to  the  internal  sphincter 
ani.  They  also  form  the  muscular  layer  of  the  mucous  membrane 
from  the  pylorus  to  the  anus  in  man,  and  constitute  the  scattered 
fasciculi  in  the  villi. 

2.  In  the  air-passages,  a  layer  of  contractile  fibre-cells  (smooth 
muscular  fibres),  exists  in  the  posterior  wall  of  the  trachea,  and 
extends  through  the  bronchial  tubes  to  their  finest  subdivisions,  as 
a  complete  muscular  membrane. 

3.  In  the  urinary  organs,  the  smooth  fibres  were  first  found  to 
extend  throughout  the  male  urethra  by  Mr.  Hancock,  of  London. 
They  also  form  two  distinct  layers  in  the  bladder,  and  a  layer  ex- 
tending through  the  ureters  into  the  pelvis  of  the  kidney. 

4.  In  the  male  sexual  organs,  they  are  found  in  the  dartos,  exter- 
nally to  the  tunica  vaginalis,  in  the  vas  deferens,  the  vesiculce  semi- 
nales,  the  prostate,  around  Cowper's  glands,  and  in  the  corpora 
cavernosa  penis,  and  the  subcutaneous  areolar  tissue  of  this  organ. 

5.  The  female  sexual  organs  contain  the  smooth  muscular  fibres 
in  the  corpora  cavernosa  of  the  clitoris,  the  vagina,  the  uterus 
(where  they  become  even  gV  of  ^^  i'lch  long  during  pregnancy),  in 
the  Fallopian  tubes,  in  different  places  in  the  broad  ligaments  of 
the  uterus,  in  the  round  ligaments,  and  those  of  the  ovaries.  They 
also  exist  in  the  areol£e  of  the  lacteal  glands,  and  the  nipples. 

6.  In  the  vascular  system,  these  fibre-cells  exist  in  the  middle  coat 
of  all,  and  most  in  the  smaller,  arteries ;  and  in  that  of  most  veins, 
and  of  the  lymphatics,  except  the  finest;  also  in  the  lymphatic 
glands  of  some  lower  animals  (iTe^/e/f^r) ;  and  the  external  tunic 


388  THE    TISSUES. 

of  many  veins.     In  the  smallest  arteries  they  are  elongated,  or  even 
round  cells;  which  is  to  be  regarded  as  a  less  developed  form. 

7.  In  the  skm^  this  tissue  appears  in  the  form  of  minute  fasciculi 
upon  the  hair-sacs,  and  which  are  hence  called  arrectores  fill  (p. 
267) ;  and  in  many  of  the  sudoriparous  and  sebaceous  follicles. 
Similar  arrectores  have  also  been  found  by  Mr.  Lister  in  the  scalp ; 
these  little  muscles  being  about  5^0  of  an  inch  in  diameter.  Their 
existence  in  the  dartos,  the  areola  and  the  mammilla,  has  already 
been  mentioned;  and  Kolliker  asserts  that  they  exist  in  all  situa- 
tions where  hairs  occur. 

8.  In  the  eye,  smooth  fibre-cells  form  both  the  sphincter  and  the 
dilator  (the  circular  and  the  radiating  fibres)  of  the  pupil,  and  the 
tensor  clioroideoe.  (ciliary  muscle). 

[9.  The  spleen  in  many  animals  has  this  tissue  in  its  outer  coat, 
and  in  its  trabecules,  mixed  with  areolar  tissue ;  but  it  is  not  found 
in  the  human  spleen.] 

10.  Finally,  this  tissue  forms  an  incomplete  coat  in  Wharton's 
duct,  and  in  the  ductus  communis  choledochus;  while  the  gall- 
bladder is  completely  lined  by  a  layer  of  it. 

Peculiarities. — The  fibre-cells  of  the  uterus  demand  a  special 
notice. 

Muscular  Fibre- Cells  of  the  Uterus. 

The  fibre-cells  of  the  uterus,  while  in  its  normal  state,  are  quite 
short;  being  only  g^'^g  to  ^^\o  of  an  inch  in  length,  and  g^'g^  of 
an  inch  wide.  As  it  enlarges  after  impregnation,  and  finally  aug- 
ments to  twenty-four  times  its  original  size  {3Ieckel),  all  its  histolo- 
gical elements  undergo  an  increased  development.  But  only  the 
changes  in  its  fibre-cells  will  be  considered  here. 

Kolliker  has  ascertained  that  the  walls  of  the  uterus  increase  in 
thickness  up  to  the  fifth  month  of  gestation,  and  then  gradually 
become  thinner,  while  its  cavity  increases  up  to  the  full  term;  and 
that  so  far  as  the  muscular  structure  is  concerned,  there  is  both  an 
enlargement  of  the  original  fibres  and  a  production  of  new  ones. 
At  the  end  of  5J  to  6  months  after  impregnation,  the  fibres  have 
become  3^^^  to  ts^  of  an  inch  long,  ^^'^g  to  vjijVtr  of  an  inch  wide, 
and  ggjjg  to  ^2'gs  of  an  inch  thick;  instead  of  the  dimensions  men- 
tioned above.  Consequently,  their  length  is  increased  from  seven 
to  eleven  times ;  and  their  width  from  two  to  Jive  times.  Acetic  acid 
brings  out  a  distinct  cell- wall  inclosing  these  large  fibres. 


MUSCULAR   FIBRE-CELLS. 


389 


On  the  other  hand,  the  new-formation  of 
fibres  is  going  on  during  the  first  half  of  preg- 
nancy; when  fibre-cells  in  all  stages  of  deve- 
lopment occur  in  great  numbers.  Fig.  244,  a,  re- 
presents the  appearance  of  these  during  the 
sixth  month.  It  appears  that  no  new  develop- 
ment of  fibres  occurs  after  the  sixth  month  is 
completed;  subsequently  to  that  period,  Kolliker 
could  find  only  the  colossal  fibres,  already  de- 
scribed.    (Fig.  244.) 

After  parturition,  the  uterus  is  diminished  in 
respect  to  all  its  histological  elements.  But  of 
its  muscular  fibres  some  are  doubtless  com- 
pletely resorbed ;  while  others  become  atro- 
phied. Indeed,  in  three  weeks  after  parturi- 
tion, the  fibres  are  found  to  be  as  short  as  in  the 
virgin  uterus.  Fat-drops  also  appear  in  them ; 
and  this  change  can  only  be  regarded  as  essen- 
tially a  fatty  degeneration,  to  a  certain  extent, 
of  the  fibre-cells.  Their  appearance  at  this  pe- 
riod is  seen  in  Fig.  248. 


Fig.  248. 


Smooth  mtiscular  fi- 
■bres  from  the  uterus 
three  weeks  after  partu- 
rition, showing  fat-drops 
in  their  interior.  The 
four  cells  at  the  left  have 
been  treated  with  acetic 
acid.    {Kolliker.) 


Distribution  of  Muscular  Fibre-  Cells  in  the  Lower  Animals. 

It  is  a  singular  fact  that  the  smooth  muscular  fibre  is  not  found 
at  all  in  the  Invertebrata ;  the  fibres  thought  to  be  such,  actually 
being  allied  genetically  to  the  striated  muscular  fibres  of  the  higher 
animals.  {Kolliker.)  The  following  peculiarities  occur  in  the  Ver- 
tebrata: — 

1.  In  the  mammalia,  except  man,  these  fibres  fgrm  the  genito- 
rectal  muscle.  In  the  orang-outang  they  are  found  upon  the  hair- 
sacs,  as  in  man.  They  also  occur  in  the  spleen  of  many  mamma- 
lia (p.  388,  9). 

2.  In  birds,  smooth  muscular  fibres  exist  in  the  skin,  forming  the 
muscles  of  the  quill-feather;  the  latter  having  tendons  of  elastic 
tissue.  In  the  gizzard  of  birds  they  are  of  a  bright  red  color,  and 
are  united  with  a  tendinous  membrane. 

3.  In  the  amphibia,  they  exist  in  the  iris.  Also  in  the  frog,  they 
are  found  in  the  lungs. 

4.  In  fishes,  they  are  found  in  the  swimming  bladder.  In  the 
plagiostomata  they  occur  in  the  mesentery,  and  in  the  osseous 
fishes  in  the  campanula  Halleri. 


390  THE   TISSUES. 

Functions  of  the  Muscular  Fibre-  Cells. 

The  tissues  thus  far  described,  have  manifested  physical  proper- 
ties only.  But  muscular  fibre-cells  are,  like  the  striated  muscular 
fibres,  endowed  with  a  vital  property,  contractility^  and  the  power  of 
contraction;  or  of  spontaneously  shortening  themselves,  when  excited 
by  an  appropriate  stimulus.  This  latter  is  often  brought  to  them 
by  a  nerve;  but  not  always,  nor  so  generally  as  is  the  case  with 
the  striated  fibres.  Hence  they  are  not  so  abundantly  supplied 
with  the  large  (motor)  nerve-fibres.  In  the  alimentary  canal,  the 
muscular  coat  is  excited  to  contraction  more  especially  by  the  con- 
tents of  the  canal  itself;  and  this  is  probably  also  true  of  the  bron- 
chial tubes,  the  blood-  and  lymph-vessels,  the  bladder  and  the 
uterus. 

Hence,  the  motion  is  transmitted  along  a  membraniform  expan- 
sion of  smooth  muscular  fibre  somewhat  slowly.  The  fibres  not 
being  bound  up  into  parallel  fasciculi  to  form  muscles,  but  being 
interwoven,  and  each  contracting  independently  of  the  rest — the 
movement  of  the  first  excites  the  rest  in  contact  with  it,  and  thus 
the  action  is  propagated  to  a  distance.  This  peculiarity  has  given 
to  the  motions  of  the  alimentary  canal  the  name  of  vermicular  or 
peristaltic  motion.  The  more  or  less  rhythmical  character  of  the 
contractions  of  this  kind  of  muscular  fibre,  is  also  probably  due  to 
the  anatomical  peculiarity  just  mentioned.  This  is  best  seen  in  the 
case  of  uterine  contractions ;  and  also  in  cases  of  colic,  and  of  cal- 
culus in  the  bladder  or  in  the  ureters. 

The  contractions  of  the  smooth  muscular  fibres  are  not  in  the 
least  degree  under  the  control  of  volition.  Those  who  maintain 
that  parturitiorf  is  in  some  instances  voluntarily  deferred  (after  it 
actually  commences  at  the  end  of  the  full  term),  and  then  again 
voluntarily  recommenced,  are  deceived  by  appearances  which  a 
knowledge  of  the  reflex  function  of  the  spinal  cord  at  once  explains 
away. 

Where  a  required  motion  is  to  be  of  slight  extent,  internal,  not 
rapid,  and  not  at  all  influenced  by  the  will — it  is  delegated  to 
the  smooth  muscular  fibre.  When  either  or  all  of  these  require- 
ments are  to  be  reversed,  the  striated  muscular  fibre  is  employed 
instead.  It  is  therefore  physiologically  inferior  to  the  latter.  Histo- 
logically, also,  it  may  be  regarded  as  a  lower  development,  as  will 
appear. 


MUSCULAR  FIBRE-CELLS — DEVELOPMENT. 


391 


The  smooth  muscular  fibre  manifests  the  rigor  mortis,  like  the 
striated  (p.  405). 

Development  of  Muscular  Fibre- Cells. 

There  is  nothing  peculiar  in  the  development  of  muscular  fibre- 
cells.  They  are  formed  merely  by  the  elongation  of  cells  originally 
rounded;  the  cell-wall  disappearing  (in  most  cases,  at  least)  after 
forming  the  homogeneous  soft  substance  already  described — the 
musculine. 

The  nutrition  of  smooth  muscle  is  probably  very  active,  though 
less  so  than  that  of  striated  muscular  fibre.  Lehmann's  investi- 
gations in  regard  to  the  fluid  which  bathes  the  fibres  show  that  it 
has  an  acid  reaction,  and  contains  creatine  and  inosite,  besides  lactic, 
acetic,  and  butyric  acid. 

Regeneration  of  Smooth  Muscular  Fibre. 
It  is  not  certainly  known  whether  this  kind  of  muscular  fibre  is 
reproduced  in  cases  of  loss  of  substance.     It  is,  however,  probably 
not  reproduced,  but  is  replaced  by  areolar  tissue. 

Pathological  Conditions  and  New  Formations  of  Muscular  Fibre- Cells. 

Smooth  muscular  fibre  is  liable  to  hypertrophy  and  to  atrophy, 
like  the  striated  form.     It  also  becomes  paralyzed  like  the  latter, 
and  is  very  liable  to  fatty  de- 
generation. ^  ^^'  J 

Pathological  new  formations  of 
this  tissue  occur  in  some  cases  of 
uterine  tumors. 

1.  Hypertrophy  of  the  smooth 
muscular  fibre  is  usually  of  limit- 
ed extent,  and  recognizable  even 
by  the  naked  eye,  by  the  pale-red 
fibrillation.  Occurring  in  the  py- 
loric portion  of  the  stomach,  this 
part  sometimes  becomes  an  inch 
or  more  thick,  the  circular  fibres 
being  mainly  increased.  An  are- 
olated  appearance  is  produced  in 
the  hypertrophied  mass  by  the 
development  at  the  same  time  of 
the  areolar  tissue  surrounding 
the  fasciculi,  and  which  increases  in  thickness  towards  the  submu- 
cous tissue.  In  certain  layers  of  the  muscular  coat,  flattened  cells 
are  met  with,  resembling  epithelial  cells,  but  having  an  oblong  nu- 


Transverse  section  of  the  hypertrophied  mus- 
cular layer  of  the  stomach,  hoiled  iu  acetic  acid, 
and  dried,  a,  a.  Smooth  muscular  fibres,  divided 
transversely,  h,  b.  Areolar  tissue  bundles. 
(Wdd.) 


392  THE   TISSUES, 

cleus.  These  are  probably  the  embryonic  forms  of  tlie  fibre-cells, 
( Wedl.)  Fig.  249  shows  the  fibres  and  the  connective  tissue  inclosing 
them,  as  seen  in  a  transverse  section.  The  submucous  tissue  is  at 
the  same  time  either  thickened,  or  infiltrated  with  a  gelatinous  sub- 
stance. 

Hypertrophy  of  the  smooth  muscular  tissue  is  usually  attributed 
to  a  previous  inflammation  in  the  part;  and  Engel  has  shown  that 
such  a  connection  exists, 

2.  Atrophy  of  the  smooth  muscular  tissue  occurs  as  a  consequence 
of  old  age,  and  of  diseases  attended  by  emaciation, 

3.  Fatty  degeneratioyi  of  the  contents  of  the  muscular  fibre-cells  is 
their  most  common  form  of  involution;^  much  fat  occurring  at  the 
same  time  in  the  interstitial  connective  tissue.  This  last  form  is 
seen  most  strikingly  in  the  intestinal  canal  and  the  urinary  bladder. 
The  involution  of  the  smooth  fibres  of  the  uterus  after  parturition 
has  already  been  explained  (p.  389). 

4.  Pathological  neiv  formations  of  smooth  muscular  fibre  very  rarely 
occur.  Their  new  formation  in  the  uterus  during  pregnancy  (p,  389) 
must  be  regarded  as  a  physiological  change, 

II,  Striated  Muscular  Tissue. 

It  is  of  this  tissue  mainly  that  the  muscles  proper  are  formed; 
and  its  histological  and  its  physiological  relations  are  of  the  highest 
importance. 

This  form  of  contractile  tissue  consists  of  fibres  marked  with 
transverse  striae,  (Fig,  250.)  The  length  of  the  fibres  varies  ex- 
ceedingly, they  sometimes  extending  through  the  whole  length  of 
the  fleshy  part  of  a  muscle.  Their  diameter  varies  from  3  o'(j^  to 
-^l-Q  of  an  inch;  the  average  being  about  g^^  of  an  inch.  They 
are  larger  on  the  trunk  and  the  extremities  than  on  the  head ;  but 
their  size  is  the  same  in  the  two  sexes,  though  the  contrary  has 
sometimes  been  asserted.  They  are  about  one-third  as  large  in  the 
foetus  as  in  the  adult.  When  packed  together  in  fasciculi,  they 
assume  the  form  of  round  polygonal  prisms,  as  seen  in  a  transverse 
section,  in  Fig,  263;  when  isolated,  they  approach  to  the  cylindrical 
form.  The  striae  are,  on  an  average,  about  TTT^tyxr  of  an  inch  apart. 
Various  hypotheses  have  been  resorted  to,  to  account  for  them;  but 
it  is  believed,  with  Kolliker,  that  "it  is  still  doubtful  to  what  the 
striation  is  due,"  though  it  is  clearly  a  physical  and  not  a  vital  phe- 

'  This  term  is  used  to  denote  a  pathological  change  or  descending  metamorphosis, 
in  the  histological  elements  of  a  tiiisue  or  organ.  It  is,  however,  also  applied  to  the 
atrophy  undergone  by  the  uterus  immediately  after  parturition. 


STRIATED   MUSCULAR   FIBRE. 
Fig.  250. 


393 


Praginents  of  striated  muscular  fibres,  showing  a  cleavage  in  opposite  directions.  (Magnified  300 
diameters.)  1.  Longitudinal  cleavage.  The  longitudinal  and  transver.se  lines  are  both  seen.  Some 
longitudinal  lines  are  darker  and  wider  than  the  rest,  and  are  not  continuous  from  end  to  end  ;  thi.« 
results  from  partial  separation  of  the  fibrillse.  6.  Fibrilla;  separated  from  one  another  by  violence 
at  the  broken  end  of  the  fibre,  and  marked  by  transverse  lines  equal  in  width  to  those  on  the  fibre. 
7,  8,  represent  two  appearances  commonly  presented  by  the  separated  single  fibrilla?  (more  highly 
magnified).  At  7,  the  borders  and  transverse  lines  are  all  perfectly  rectilinear,  and  the  included 
spaces  perfectly  rectangular.  At  8,  the  borders  are  scalloped,  the  spaces  bead-like.  When  most 
distinct  and  definite,  the  fibrilla  presents  the  former  of  these  appearances. — 2.  Transverse  cleavage. 
The  longitudinal  lines  are  scarcely  visible.  3.  Incomplete  fracture  following  the  opposite  surfaces 
of  a  disk,  which  stretches  across  the  interval  and  retains  the  fragments  in  connection.  The  edge 
and  surface  of  the  disk  are  minutely  granular,  the  granules  corresponding  in  size  to  the  thickness  of 
the  disk,  and  to  the  distance  between  the  faint  longitudinal  lines.  4.  Another  disk  nearly  detached. 
5.  Detached  disk  more  highly  magnified,  showing  the  "  sarcous  elements." 


Fig.  251. 


noraenou.    The  largest  and  the  smallest  fibres  are  sometimes  found 
side  by  side. 

Bach  striated  fibre  consists  of  two  distinct  por- 
tions: jirst^  the  rayolemma;  dcadi^  secondly ^\hQ  mj- 
oline. 

1.  The  myolem'ma}  is  the  envelop  containing 
the  mjoline.  It  is  merely  a  tube,  closed  at  both 
ends,  of  simple  membrane  (Fig.  251);  in  or  un- 
derneath which  (for  this  point  is  not  jet  settled) 
nuclei  are  brought  into  view  by  acetic  acid.  (Fig. 
254.)  Kolliker  maintains  that  it  is  not  an  albu- 
minous compound,  but  is  at  least  similar  to  elastic  ■iTl^ki^^I^l-f 
tissue.     Certainly  it  may  be  proved  to  be  elastic,  ~~" 

and  to  fit  closely  upon  its  contents,  in  the  normal       ^'y-\^^^^j^  "f  '^/'"•■i 

•^        •>  '  muscular   fibre   ot    the 

state  .^  skate. 


•  From  jun?,  muscle,  and  \ifji.fxa,  coat  or  sheath.  It  is  also,  less  accurately,  named 
sarcolemma,  by  Kolliker  and  others. 

^  It  should  be  here  remarked  that  Drs.  Busk  and  Huxley  deny  the  existence  of 
the  myolemma  as  a  distinct  structure  ;  affirming  that  it  is  merely  the  outer  portion 
of  the  matrix  containing  the  fibrilla}. 


894  THE    TISSUES. 

2.  The  myoline  is  the  demi-solid  substance  filling  the  mjolemma, 
and  on  the  surface  of  this  are  the  transverse  markings  before  men- 
tioned. It  consists,  first^  of  very  minute  threads,  called  fihrillce, 
placed  side  by  side,  from  ojs^-q-q  ^o  ^^j'^^  of  an  inch  in  diameter,  and 
averaging  about  txt^tt^  of  ^^^  moh ;  between  which  is,  secondly,  the 
muscular  juice,  to  be  described  under  the  chemical  composition  of 
this  tissue.  Each  one  of  these  fibrillae  has  its  own  transverse  mark- 
ings. Fig.  250, 1,  shows  a  fibre  splitting  into  its  compound  fibrillas 
in  consequence  of  maceration.  The  same  cause  sometimes  produces 
a  transverse  cleavage  of  the  fibres;  in  which  case  the  fibre  has  been 
described  as  being  made  up  of  superimposed  disks,  instead  of  fibrillae. 
Fig.  250,  2,  represents  this  form  of  cleavage.  Often,  also,  a  longi- 
tudinal striation  is  apparent.  The  fibrillae  are  not  tubular  in  man 
(as  in  some  of  the  lower  animals),  but  are  homogeneous  throughout. 
The  fibrillas  are  connected  together  by  an  albuminous  tenacious 
intermediate  substance  of  a  double  nature:  viz.,  the  "muscular  juice" 
hereafter  to  be  described ;  and  a  granular  molecular  substance — 
probably  fat  in  part — which  certain  distinguished  microscopists 
have  seen  lying  between  the  extremities  of  the  fibrillas  of  a  fibre 
which  had  been  transversely  divided.  Each  fibrilla  is  also  by  Todd 
and  Bowman  regarded  as  being  composed  of  cells,  called  "the  sar- 
cous  elements,"as  represented  in  Fig.250, 5  and  6. 
Fig,  252.  These  cells  average  about  ^^^-q  of  an  inch  in  di- 

ameter ;  and  as  the  alternate  ones  are  often  larger 
than  those  between  them,  the  striated  appearance 
of  the  fibrillaa  has  sometimes  been  accounted  for 
in  this  way. 

Peculiarity. — In  the  heart  (of  man,  and  proba- 
bly of  all  mammals),  anastomosing  and  dividing 
fibres  are  found.  Branched  fibres  are  also  found 
in  the  human  tongue.  (Fig.  252.) 

The  striated  muscular  tissue  is  abundantly  sup- 
plied with  bloodvessels  and  nerves  (both  the  fine 

Anastomo.sing    fibres  ,       ,  />i  \  i  -i  •   i 

from  tho  liuman  Ueart.     ^^^  ^hc  coarsc  ncrvc-fibres),  and  scantily  with 
(KiUiker.)  lymphatics.    (See  Section  II,  of  this  chapter.) 

Chemical  Composition  and  Physical  Properties  of  Striated  Musctilar 

Tissue. 
There  is  reason  to  believe  that  the  chemical  composition  of  the 
two  forms  of  muscular  tissue  is  identical.    C  Schmidt  supposed  h^ 


STRIATED   MUSCULAR   FIBRE.  395 

had  proved  this  to  be  the  fact  some  years  ago.     We  have  to  con- 
sider the  composition  of — 

I.  The  muscular  fluid. 
II.  The  masculine. 
III.  The  myolemma,  containing  both  of  the  preceding. 

I.  The  "muscular  juice,"  as  it  is  termed  by  Liebig,  surrounds  the 
fibre-cells  of  the  smooth  muscle;  and  is  also  contained  within  the 
myolemma  of  striated  muscular  fibre,  where  it  permeates  between 
the  fibrillae.  It  is  easily  expressed  from  fresh  muscle,  and  is  a  de- 
cidedly acid,  albuminous  fluid.  Its  albumen  may,  however,  be  in 
part  obtained  from  the  blood  of  the  muscular  mass;  while  its  large 
amount  of  caseine  is  peculiar  to  it.^  It  is  from  72.56  to  74.45  per 
cent,  water  {Von  Bibra);  there  being,  on  an  average,  10  per  cent. 
less  water  in  muscle  than  in  blood-serum.  It  also  contains  creatine, 
creatinine,  inosic  acid,  lactic  acid,  and  a  very  little  fat.  Scherer  has 
also  found  in  it  acetic  and  formic  acid ;  and  in  that  obtained  from 
the  heart  of  the  ox,  he  found  a  peculiar  substance  which  he  terms 
inosite  or  muscle-sugar.  The  muscular  juice,  like  most  acid  fluids, 
also  contains  an  abundance  of  potash  salts,  and  of  phosphates,  while 
it  is  poor  in  salts  of  soda  and  in  chlorides.  It  appears  that  in  the 
horse  there  are  twenty-nine  times,  and  in  the  ox  forty  six  times,  as 
much  potash  in  the  muscular  juice  as  in  the  blood.  There  is  about 
ten  times  as  much  chloride  of  sodium,  on  the  other  hand,  in  the 
blood-serum  as  in  the  muscular  juice  of  the  horse.  {R.  Weber.) 
"While  the  phosphate  of  lime  is  far  more  abundant  in  the  blood 
than  the  phosphate  of  magnesia,  the  reverse  is  true  of  the  muscular 
fluid.  It  has  been  seen  that  the  chloride  of  potassium  is  more  abun- 
dant than  that  of  sodium,  and  that  the  former  is  often  mistaken  for 
the  latter  (p.  49).  About  twenty-three  times  as  much  phosphoric 
acid  exists  in  the  ash  of  horse's  muscle  as  in  that  of  the  blood- 
serum;  more  than  is  sufficient  to  form  all  the  neutral  phosphates 
of  the  alkalies. 

What  the  precise  relation  is  between  the  function  of  the  muscular 
fibre  on  the  one  hand,  and  the  chemical  constitution  of  the  muscu- 
lar fluid  on  the  other,  is  unknown,  Liebig  calculates  that  the  stri- 
ated muscles  alone  contain  more  than  enough  free  acid  to  destroy 
the  alkalinity  of  all  the  blood;  and  that  the  opposite  state,  in  this 

'  The  fluid  of  the  smooth,  however,  contains  more  caseine  and  less  albumen  than 
that  of  striated  muscle.     In  the  latter,  albumen  alone  is  often  found. 


896  THE   TISSUES. 

respect,  of  the  muscular  fluid  and  the  alkaline  blood  circulating 
through  the  muscle,  either  occasions,  or  is  occasioned  by,  an  elec- 
trical current;  which,  it  is  implied,  may  be  the  exciting  cause  of 
muscular  contraction — a  proposition  we  hesitate  to  adopt.  Experi- 
ments, however,  point  to  the  conclusion  that  muscle  loses  its  power 
of  contraction  in  proportion  as  its  fluid  is  diluted. 

II.  After  the  muscular  fluid  is  removed  by  pressure  from  the 
myolemma,  the  solid  substance  of  the  fibrils  still  remains.  This  is 
an  albuminous  substance,  soluble  in  extremely  dilute  hydrochloric 
acid,'  and  is  the  most  essential  element  of  muscular  tissue.  It  has 
already  been  described  as  musculine  (p.  97).  It  exists  equally  in 
striated  fibre  and  in  the  muscular  fibre-cells,  and  the  vital  property 
of  contractility  doubtless  inheres  in  it,  wherever  found.  There  is 
less  of  it  within  the  myolemma  of  young  than  of  adult  animals. 

III.  The  chemical  relation  which  the  myolemma  bears  to  the  in- 
closed cylinder  of  musculine  has  not  been  determined ;  but  the 
substance  of  the  nuclei  inclosed  in  it  does  not  differ  much  from 
musculine.  [Lehmann)  From  what  precedes,  there  will  be  less 
musculine,  in  proportion,  in  young  animals.  In  the  contractile 
fibre-cells,  on  the  other  hand,-  the  myolemma  is  absent,  or  at  least 
is  generally  not  demonstrable  (p.  384), 

Of  the  three  distinct  substances  included  in  the  analysis  of  muscu- 
lar tissue — the. myolemma,  the  muscular  fluid,  and  the  musculine — 
the  last  alone  is  an  immediate  principle.  It  is  impossible  to  isolate 
the  muscular  tissue  entirely  from  the  bloodvessels  and  their  con- 
tents, from  the  areolar  tissue  in  the  muscular  sheaths,  and  from  fat 
between  the  myolemmata.  After  instituting  all  practicable  pre- 
cautions, Lehmann  found  the  following  as  the  average  result  of  his 
analyses  of  the  muscular  substance,  more  especially  of  oxen : — 

Per  cent. 

Water 74.0  to  80.0 

Solid  constituents         .        ,        .     26.0  to  20.0 


100.0     100.0 

Per  cent. 

Muscular  fibre  (musculine)      .        .        .     15.4    to  17.7 
Gelatigenous  substance  (myolemmata  and 

perimysia)   ......       0.6    to    1.9 

•  One  part  to  one  thousand  of  water. 


STRIATED   MUSCULAR   FIBRE. 


397 


Albumen  (and  caseine)    . 
Creatine  .         .         .         .         . 
Creatinine  (undetermined). 
Inosic  acid  (do.). 

Fat,  within  the  myolemmata  and 

blood  between  the  perimysia 
Lactic  acid  (CgHjOj.HO) 
Phosphoric  acid 
Potassa    ..... 

Soda 

Chloride  of  sodium  (potassium) 
Lime        ..... 
Magnesia         .... 


The  color  of  muscular  fibre  is  due  not  to  the  blood  in  the  ves- 
sels, but  to  a  peculiar  pigment,  very  similar  to  the  hsematine  of  the 
blood,  but  probably  not  identical  with  it.  At  least,  it  adheres  in  a 
free  state  to  the  fibrillce,  since  it  may  be  extracted  from  them  by 
water,  and  coagulates  with  the  albumen  of  the  muscular  fluid.  It 
is  not  essential  to  contractility;  since  the  muscles  of  many  animals 
are  white,  though  perhaps  as  vascular  as  the  red  muscles  of  other 
species. 

Another  physical  property  of  striated  muscular  tissue — elasticity 
— will  be  described  in  the  next  section. 


Per  cent. 

.   2.2  to 

3.0 

.   0.07  to 

0.14 

in  the 

1.5  to 

2.3 

.   0.6  to 

0.68 

.   0.66  to 

0.70 

.   0.50  to 

0.54 

.   0.07  to 

0.09 

.   0.04  to 

0.09 

.   0.02  to 

0.03 

.   0.04  to 

0.05 

Distrihution  of  Striated  Muscular  Fibre. 
The  striated  muscular  fibre  is  the  peculiar  tissue  of  the  muscles 
properly  so  called ;  while  none  of  the  latter  are  ever  formed  of  the 
smooth  fibre,  as  already  stated.     It  is,  therefore,  distributed : — 

1.  In  all  the  muscles  proper  in  the  body,  including  the  internal 
(diaphragm,  levator  ani,  those  of  the  eyeball,  &c.),  as  well  as  those 
of  the  head,  neck,  trunk,  and  extremities. 

2.  In  the  heart  and  the  great  veins  opening  into  it — the  inferior 
cava  to  the  diaphragm,  and  the  superior  cava,  and  the  innominata?, 
to  the  clavicles. 

3.  Scattered  striated  fibres  are  found  in  the  cesophagus,  and  also 
in  the  round  ligaments  of  the  uterus — mixed  with  the  smooth 
fibres. 


398  THE   TISSUES. 


Distribution  and  Peculiar  Forms  of  Striated  Fibre  in  the  Lower 

Animals. 

I.  In  the  vertebrata,  generally,  the  distribution  of  striated  fibres 
is  as  in  man.     The  following  peculiarities  are  noted : — 

1.  In  the  oesophagus  (with  smooth  fibres),  of  some  mammalia 
and  of  the  plagiostome  fishes ;  around  the  contractile  organ  of  the 
pharynx  of  the  carp ;  and  in  the  stomach  of  cobites  fossilis,  and  the 
intestine  of  tiiica  chrysitis,  and  around  the  anal  glands  and  Cowper's 
gland  in  mammals. 

2.  In  the  skin  of  some  mammalia,  birds,  serpents,  and  tailless 
batrachians  (frog,  &c.),  and  the  tactile  hairs  of  mammals. 

8.  In  the  lymph-hearts  of  many  birds  and  amphibia;  and  in  the 
right  auriculo- ventricular  valve,  in  birds,  and  the  ornithorhynchus. 
Also  in  the  inferior  vena  cava  of  the  seal,  close  above  the  dia- 
phragm. 

4.  In  the  interior  of  the  eye  in  birds,  and  around  the  poison- 
gland  in  serpents. 

The  anastomosing  fibres  already  mentioned,  probably  occur  in 
the  hearts,  and  the  lymph-hearts  of  all  animals.  Branched  fibres 
also  occur  in  the  tongue  of  all  the  vertebrata  probably ;  and  are 
found  in  the  upper  lip  of  the  rat. 

II.  In  the  invertebrata,  all  the  muscular  fibres  belong  genetically 
to  the  striated  form,  whether  they  are  clearly  striated  or  not. 
{Kolliker)  The  muscles  of  insects,  and  of  the  medusas,  and  indeed 
the  heart,  intestine,  and  muscles  of  the  genital  organs,  of  the  inver- 
tebrata generally,  are  distinctly  striated.  It  is  only  necessary, 
therefore,  to  notice  the  peculiar /orws  of  striated  fibre  in  this  class, 
which  are  enumerated  by  KoUiker. 

1.  Muscular  tubes,  with  homogeneous  semi-solid  non-striated 
contents;  i.  e.  the  fibre  is  like  the  non-striated  or  smooth  fibre,  with 
a  distinct  myolemma ;  as  in  most  of  the  mollusca,  annelidse,  and 
radiata. 

2.  Tubes  (myolemmata),  containing  a  semifluid,  homogeneous 
layer  in  contact  with  them,  and  a  fluid  or  granular  central  sub- 
stance frequently  transversely  striated  or  nucleated ;  as  in  Lumbri- 
cidse,  Hirudiaidae,  Carinaria,  and  Petromyzon  and  Paludina  in 
part. 

3.  Similar  tubes,  having  the  cortical  layer  of  their  contents  trans- 
versely striated,  but  not  divisible  into  distinct  fibrillse ;  as  in  many 
muscles  of  the  Hirudinida3.  This  form  is  found  in  the  tongue, 
pharynx,  sphincter  ani,  &;c.,  of  fishes  even.  These  tubes  contain  a 
fluid  in  their  centre. 

4.  Tubes  precisely  like  the  preceding,  except  that  they  have  no 
central  cavity  {i.  e.  are  demi-solid  throughout),  and  break  often  into 
disks,  though  not  into  fibrillar;  as  in  many  Articulata  {Sal'pai\  and 
some  Radiata. 


STRIATED   MUSCULAR   FIBRE. 


399 


5.  Tubes  readily  breaking  into  fibrillae;  or  precisely  like  the 
striated  fibre  in  the  Mammalia,  as  in  certain  muscles  of  insects. 

6.  Lastly,  simple  isolated  cells,  containing  a  transversely  striated 
substance  which  fills  the  whole  cell  or  only  forms  a  thin  layer  upon 
its  internal  surface.  These  exist  also,  according  to  Kolliker,  in  the 
endocardium  of  the  Euminantia;  constituting  the  peculiar  cartila- 
ginous striae  first  observed  by  Purkinje. 


Development  of  Striated  Musadar  Fibre. 

The  myolemma  is  formed  originally  of  nucleated  cells,  first  co- 
alescing and  then  becoming  absorbed  where  they  come  into  con- 
tact, so  as  to  form  tubes  closed  at  both  extremities.  Subsequently 
the  original  homogeneous  contents  of  the  formative  cells  are  re- 
placed by  the  fibrillje,  and  thus  the  development  of  the  fibre  is  com- 
pleted. In  many  cases  the  layer  of  the  contents  next  the  myolem- 
ma alone  gives  place  to  the  myoline ;  while  the  central  part  still 
appears  like  a  canal  within  the  fibrils.  It  has  been  seen  that  this 
is  the  permanent  form  of  the  striated  fibre  in  some  insects.  After 
the  fibrillae  are  developed,  and  before  birth,  the  nuclei  disappear, 
and,  with  the  exception  of  being  smaller,  the  fibres  present  the  same 
appearance  as  in  the  adult. 

More  particularly — in  the  embryo — at  the  end  of  the  second 
month,  the  fibres  have  the  form  of  elongated  bands  12^00  of  ^.n  inch 
broad,  with  nodular  enlargements  at  different  points  where  elon- 
gated nuclei  are  situated.     (Fig.  253.)     These  bands  have  either  a 


Fig.  253. 


Fig.  254. 


Fig.  253.  Stages  of  the  development  of  striated  muscular  fibre.  1.  Arrangement  of  the  primitive 
cells  in  a  linear  series,  after  Schwann.  2.  The  cells  united  ;  the  nuclei  separated  and  some  broken 
up,  longitudinal  series  becoming  apparent — from  a  foetal  calf  three  inches  long.  3,  4.  Transverse 
strisa  apparent.  In  (3)  the  nuclei  are  internal,  and  bulge  the  fibre.  In  (4)  they  are  apparently  on 
the  surface — from  a  foetal  calf,  two  months  old.  5.  Transverse  stripes,  fully  formed  and  dark  ; 
nuclei  disappearing  from  view — from  the  now-born  infant. 

Fig.  2.51.  Muscular  fibre,  from  the  adult,  treat<'d  with  acid — showing  the  nuclei.  (Magnified  about 
300  diameters.) 


400  THE   TISSUES. 

homogeneous  or  a  finely  granular  aspect,  and,  rarely,  exhibit  a  faint 
trace  of  transverse  striation.  In  the  fourth  month,  they  are  mostly 
from  ^^'s 5  *'0  54'o  0  of  an  i'^ch  in  diameter.  The  larger  ones,  though 
still  flattened,  are  now  of  uniform  width,  thicker  than  before, 
transversely  striated,  and  with  fibrils  capable  of  being  isolated. 
(Fig.  253,  3).  The  musculine  does  not,  however,  yet  entirely  fill  the 
myolemma,  but  forms  a  tube  in  contact  with  its  inner  surface,  con- 
taining some  of  the  original  contents  of  the  myolemma  in  its  cen- 
tre. Thus  the  musculine  is  the  part  of  the  fibre  which  is  last  de- 
veloped. The  myolemma  may  occasionally  be  raised  like  a  very 
delicate  membrane,  by  the  imbibition  of  water.  The  nuclei  still  lie 
close  upon  the  myolemma,  as  at  first,  and  are  rapidly  multiplying ; 
being  much  more  numerous  than  at  first,  and  often  found  in  groups 
of  three  or  four,  or  even  six,  which  are  sometimes  arranged  serially. 
They  are  all  vesicular,  with  very  distinct,  simple,  or  double  nucleoli, 
and  frequently  with  two  secondary  cells  in  their  interior,  showing 
the  endogenous  development  of  the  nuclei  from  the  original  ones. 
At  birth,  the  fibres  are  5x45  ^o  t^V?  of  a,n  inch  in  diameter;  are 
solid,  rounded,  polygonal,  and  longitudinally  and  transversely  stri- 
ated, as  in  the  adult;  and  the  nuclei  have  disappeared.  (Fig.  253,  5.) 

Thus  the  myolemma  represents  the  sum  of  the  membranes  of  the 
original  coalesced  cells,  and  the  fibrillse  are  the  altered  contents  of 
the  original  tubes  (myolemmata).  A  fibre,  therefore  (and  not  a 
fibrilla,  as  Leidy  and  Keichert  maintain),  is  histologically  analogous 
to  a  contractile  fibre-cell  (p.  390);  and  the  latter  may  be  regarded 
as  a  lower  development  of  the  former. 

The  growth  of  the  striated  muscular  fibre,  must  be  referred  prin- 
cipally at  least,  to  increase  in  the  number  of  the  fibrillae,  and  of 
course  of  the  size  of  the  myolemma  containing  them.  In  other 
words,  each  fibre  grows  larger,  while  there  is  no  proof  that  new 
fibres  are  formed  even  after  the  middle  period  of  intra- uterine  life. 
Thus  the  fibres  are  about  five  times  as  thick  in  an  embryo  at  four 
or  five  months  as  at  two  months;  and  three  or  four  times  as  thick 
in  the  new-born  infant  as  at  the  period  first  mentioned.  In  the 
adult,  they  are  perhaps  five  times  as  thick  as  at  birth.  Bonders 
thinks  the  number  of  the  fihriUce  is  the  same  in  the  young  and  the 
adult  animal,  and  that  they  only  increase  in  size;  they  being  ^-  to 
f  smaller  in  the  calf  than  in  the  ox.  KciUiker,  however,  relying 
on  Harting's  assertion  that  they  are  but  little  thicker  in  the  adult 
than  in  the  foetus,  believes  their  number  increases  in  each  fibre. 


STRIATED   MUSCULAR   FIBRE. 


401 


Fig.  255. 


Striated  muscular  fibre  is  not  regenerated]  and  wounds  in  mus- 
cles heal  simply  with  a  tendinous  callus. 

The  development  of  tlie  accessory  parts  of  muscles  (tendons,  &c.) 
is  included  under  that  of  the  muscles  as  distinct  organs  (Section  II.). 

The  Function  of  Striated  Muscular  Fibre. 

Striated,  like  smooth  muscular  fibre,  is  distinguished  by  the  vital 
property  of  contractility ;  but,  unlike  the  latter,  the  former  may  be 
made  to  contract  voluntarily.  The  direct  result  of  the  contraction 
of  the  striated  fibres  in  a  muscle,  is  a 
shortening  of  it;  which  approximates  its 
two  extremities,  and  at  the  same  time 
produces  motion  of  one  of  the  parts 
(usually  a  bone)  to  which  it  is  attached. 
But  we  have  here  to  speak  of  the  con- 
traction of  single  fibres  only. 

If  a  striated  fibre  be  observed  while 
contracting,  it  is  seen  to  become  shorter 
and  thicker;  the  strise  approach  each 
other  (Fig.  255) ;  and  sometimes  the 
muscular  fluid,  forced  out  from  between 
the  fibrilla?,  causes  the  myolemma  to 
project  at  points,  forming  bullae,  as  seen 
in  Fig.  256.  It  is  scarcely  profitable  to 
inquire  what  causes  the  shortening  of 
the  fibre,  by  the  approximation  of  its 
disks,  since  it  is  a  vital  act;  and  the 
merely  chemical  explanation  suggested 
by  Liebig  is  altogether  unsatisfactory. 
But  that  the  musculine  alone  is  endowed  with  the  property  of  con 
tractility,  is  sufficiently  certain. 

Fig.  256. 


stages  of  contractiou  seen  in  muscu- 
lar fibre  of  the  skate.  The  uppermost 
figure  shows  its  state  previous  to  the 
commencement  of  active  contraction. 
a,  a,  a.  Successive  "■waves"  of  con- 
traction seen  moving  along  one  margin 
of  the  fibre  ;  marked  by  a  bulging  of 
the  margin,  an  approximation  of  the 
transverse  stripes,  and  a  conseq,nent 
darkening  of  the  spots,  b,  b,  b.  Simi- 
lar "waves"  still  moving  along  the 
fibre,  but  engaging  its  whole  thickness. 


Muscular  fibre  of  Dytiscus,  showing  the  contrncloil  st:itf  in   tho  rontrp,  the  striar  approximated,  the 
breadth  of  the  fibre  increased,  and  the  myolemma  raised  in  bulhe  on  its  surface. 

It  is,  however,  the  fact  that  ordinarily  (and  perhaps  always)  the 
immediate  stimulant  to  contraction  of  the  striated  fibres  is  an  influ- 
26 


402  THE   TISSUES. 

ence  imparted  by  a  nerve  distributed  among  them  in  the  muscle. 
Electricity,  galvanism,  and  a  variety  of  other  agents,  will,  however, 
excite  it  in  muscles  in  the  living  body,  or  in  portions  removed  from 
the  same.  In  fact,  the  only  way  in  which  a  muscular  fibre  can 
react  vitally  when  acted  upon  by  any  external  agent,  is  by  con- 
tracting, since  this  is  its  peculiar  vital  endowment.  The  shortening 
also  occurs  instantaneously. 

The  chemical  changes  which  attend  the  contraction  of  a  fibre 
are  not  all  understood.  There  is,  however,  reason  to  believe  that 
the  substance  of  the  fibrillae — the  musculine — alone  is  concerned 
actively  in  the  contraction,  and  alone  undergoes  chemical  changes 
during  it.  It  is  also  certain  that  the  contact  of  oxygen  is  necessary 
to  the  contraction  of  a  fibre,  and  that  during  it  carbonic  acid  gas  is 
formed  within  the  fibres,  and  not  in  the  bloodvessels  distributed 
among  them;  while  the  temperature  of  the  muscle  also  rises  two  or 
three  degrees.  {Becquerel  and  Breschet.)  Hence  the  contractility  of 
a  set  of  muscles  is  lost  if  their  supply  of  blood  is  cut  off. 

The  extent  to  which  a  fibre  may  become  shortened  during  con- 
traction seldom  if  ever  exceeds  two-thirds  of  its  length;  or  reduces 
the  fibre  to  one-third  of  its  original  length.  Some  give  one-third 
as  the  usual  amount  of  shortening,  the  fibre  then  being  two-thirds 
its  original  length.  Kolliker  states  that  the  average  shortening  is 
three-fourths  {i.  e.  down  to  one-fourth),  and  in  powerful  muscles  even 
five-sixths  (or  down  to  one-sixth),  of  the  original  length.  Hassall 
estimates  the  shortening  at  one-third  to  one-half  only,  of  the  original 
length. 

In  ordinary  circumstances,  not  all  the  fibres  in  a  muscle  contract 
simultaneously;  but  each  contracts  for  an  instant  and  relaxes,  while 
of  the  rest  some  are  contracting  at  the  same  time,  and  others  follow 
these  in  their  turn.  It  is  probably  only  when  the  most  powerful 
muscular  efforts  are  made  that  all  the  fibres  of  a  muscle  contract  at 
once. 

The  absolute  extent  of  motion  (or  shortening)  produced  by  a 
striated  fibre  will,  therefore,  depend  on  its  length;  while  its  con- 
tractile force  or  strength  will  depend  on  its  size,  it  being  stronger 
in  proportion  to  the  area  of  the  transverse  section  of  the  musculine 
(and  of  the  fibrillaa)  within  its  myolemma. 

So  long  as  a  muscular  fibre  is  in  a  state  of  perfect  nutrition,  it  also 
manifests  a  slight  but  constantly  exerted  tension,  called  tone  or  toni- 
city, and  in  regard  to  the  nature  of  which  very  diverse  opinions 


STRIATED    MUSCULAR   FIBRE.  403 

have  been  held.  This  property,  however,  diminishes  in  proportion 
to  the  duration  of  the  contractions  of  the  fibre,  and  is  not  again  re- 
covered till  the  fibre  has  had  time  to  rest.  It  does  not  appear  to 
depend  upon  the  constant  influence  of  the  spinal  cord,  or  on  any 
other  merely  nervous  agency.  But  that  it  depends  merely  on  a 
healthy  nutrition,  and  is  the  expression  of  the  fitness  of  the  muscle 
for  action,  is  rendered  quite  probable  from  the  effect  of  rest  in 
restoring  it,  and  from  the  loss  of  tone  and  the  flabby  state  which  are 
consequent  upon  long-continued  exertion.  This  tensive  force  being 
constantly  exerted  in  ordinary  circumstances,  produces  the  some- 
what flexed  position  of  the  limbs  in  a  sound  sleep ;  since  the  flexors 
are  so  inserted  as  to  act  to  greater  advantage  than  the  antagonizing 
extensors,  though  actually  less  strong  than  the  latter.  It  also  ac- 
counts for  the  habitual  closure  of  most  of  the  sphincter  muscles,  and 
the  deviation,  to  one  side,  of  the  tongue  or  of  the  mouth  when  the 
muscles  of  the  opposite  side  are  paralyzed.  In  all  similar  cases, 
the  sound  muscles  are  not  in  a  state  of  incessant  contraction,  as  often 
asserted ;  but  merely  in  a  state  of  tension,  and  at  rest,  while  the 
antagonizing  muscles  have  lost  Ijoth  their  contractility  and  their 
tonicity. 

The  use  of  the  muscles  is  inferred  from  the  preceding  remarks, 
and  will  be  particularly  specified  in  the  second  section  of  this 
chapter. 

Modifications  of  the  Contractility  of  the  Striated  Muscular  Fibre. 

1.  An  increased  or  an  irregularly  acting  contractile  force  of  the 
striated  fibres  constitutes  spasm.  If  the  contraction  is  constant,  it 
is  termed  tonic  spasm  (as  tetanus,  trismus,  &c,) ;  if  irregular  and  in- 
termitting, it  is  clonic  spasm,  or  convulsions  (epilepsj^,  chorea,  &c.). 

2.  A  loss  of  contractility  constitutes  paralysis,  and  in  which,  if 
complete,  all  motion  is  of  course  impossible. 

3.  The  rigor  mortis  is  that  tonic  spasm  of  all  the  muscles  which 
usually  comes  on  several  hours  after  death. 

It  is  in  some  rare  cases  entirely  absent — as  after  death  by  light- 
ning or  by  asphyxia.  It  may  also  be  so  slight,  and  last  so  short  a 
time,  as  to  escape  observation.  It  affects  the  muscles  in  the  follow- 
ing order :  those  of  the  neck  and  lower  jaw ;  those  of  the  trunk ; 
and  those  of  the  lower  and  the  upper  extremities.  It  departs  also 
in  the  same  order. 

It  affects  all  the  muscles  with  nearly  the  same  intensity;   the 


40-i  THE   TISSUES. 

flexors,  however,  being  usually  more  contracted  than  the  exten- 
sors, flexing  the  fingers  on  the  palm,  and  the  forearm  on  the  arm, 
and  closing  the  mouth  if  the  lower  jaw  had  previously  fallen.  It 
is  equally  intense  even  in  muscles  paralyzed  by  hemiplegia,  pro- 
vided they  have  not  become  much  atrophied. 

The  period  elapsing  after  death  before  its  supervention,  and  its 
duration,  are  variable.  It  usually  occurs  within  seven  hours,  and 
continues  from  twenty-four  to  thirty-six  hours.  But  twenty  or  even 
thirty  hours  may  elapse  before  it  supervenes,  and  it  may  be  pro- 
longed through  several  days.  Its  departure  is  immediately  followed 
by  decomposition.  Whe;ja  early  developed,  it  lasts  but  a  short  time, 
and  vice  versa.  Any  cause  which  has  exhausted  the  muscular  energy 
before  death,  causes  the  rigor  mortis  to  come  on  and  to  pass  off 
sooner — as  a  protracted  disease,  or  violent  efforts.  Indeed,  power- 
ful stimulation  of  the  muscles  by  electrical  currents,  immediately 
after  death,  also  produces  the  same  effect.  The  following  results 
were  obtained  by  M.  Brown-Sequard,  who  experimented  on  four 
rabbits,  reserving  a  fifth  for  comparison : — 

1.  Not  electrized;  rigidity  occuri^bd  in  10  hours,  and  remained  192 

hours. 

2.  Feebly  electrized;  rigidity  occurred  in  7  hours,  and  remained  141 

hours. 

3.  Somewhat  more  electrized;  rigidity  occurred  in  2  hours,  and  re- 

mained 72  hours. 

4.  Still  more  strongly  electrized;  rigidity  occurred  in  1  hour,  and 

remained  20  hours. 

5.  Submitted  to  a  powerful  current;  rigidity  occurred  in  7  minutes, 

and  remained  25  minutes. 

In  animals  hunted  to  death,  the  rigidity  comes  on  very  early,  and 
lasts  bat  for  a  short  time. 

On  the  other  hand,  M.  Brown-S^quard  found  that  the  rigor 
mortis  is  deferred  by  injecting  the  muscles  with  fresh  blood,  after 
death.  Staunius  also  found  it  to  occur  even  in  living  animals,  if 
the  supply  of  blood  to  a  group  of  muscles  is  entirely  cut  off.  After 
death  from  typhus,  the  limbs  sometimes  stiffen  within  fifteen  to 
twenty  minutes.  It  also  occurs  rapidly  in  infants,  and  in  old 
people. 

It  should,  however,  be  remembered  that  in  certain  states  of  the 
muscular  and  nervous  systems,  a  tetanic  rigidity  immediately  en- 


STRIATED   MUSCULAR   FIBRE.  405 

sues  after  death,  and  which  may  be  mistaken  for  the  rigor  mortis. 
This,  however,  is  in  a  few  hours  succeeded  by  a  state  of  relaxation 
of  the  muscles,  and  then  the  ordinary  rigor  mortis  supervenes. 

A  knowledge  of  all  the  facts  connected  with  this  subject  is  essen- 
tial in  certain  judicial  investigations;  in  regard  to  which  the  works 
on  medical  jurisprudence  may  be  consulted.  Its  cause  is  not  under- 
stood. It  does  not,  however,  depend  upon  the  diminished  tempera- 
ture of  the  dead  body,  since  it  often  occurs  while  the  latter  is  still 
warm;  nor  is  it  produced  by  the  coagulation  of  the  blood,  though  in 
those  cases  of  death  in  which  the  blood  does  not  coagulate  (p.  9-i,  vi.), 
the  rigidity  usually  manifests  itself  least.  We  can  hardly  say  more 
than  that  the  rigor  mortis  is  the  last  vital  act  of  the  muscles,  as  the 
coagulation  of  the  blood  is  of  the  fibrine  (p.  93,  III.). 

It  should  be  here  added,  however,  that  the  rigor  mortis  is  equally, 
if  not  more  remarkable  in  the  smooth  muscular  fibre.  The  arte- 
ries contract  so  as  to  force  their  blood  into  the  venous  system;  which 
almost  invariably  occurs  a  few  hours  after  death.  They  then  en- 
large as  the  rigidity  passes  off,  and  become  quite  flaccid.  Hence 
the  old  physiologists  believed  that  the  arteries  naturally  contained 
not  blood,  but  air,  and  named  them  accordingly.'  The  alimentary 
canal,  the  bladder,  and  the  bronchial  tubes  are  also,  for  a  time  after 
death,  contracted  in  a  similar  manner ;  and  the  post-mortem  con- 
traction of  the  parturient  uterus  in  patients  who  had  died  unde- 
livered, has  been  known  in  several  instances  to  expel  the  foetus. 

The  "  concentric  hypertrophy"  of  the  heart,  as  it  was  formerly 
called  (this  organ  being  thicker  than  usual  and  smaller),  has  been 
shown  by  Mr.  Paget  to  be  merely  the  state  of  cadaveric  rigidity 
which  usually  occurs  in  that  organ.  The  ventricles  become  rigid 
and  contracted  within  an  hour  or  two  after  death ;  and  usually  re- 
main in  that  state  for  ten  or  twelve  hours  (sometimes  twenty -four 
or  thirty-six  even),  when  they  again  relax  and  become  flaccid. 

Of  the  lower  animals  the  rigor  mortis  occurs  most  rapidly  in  those 
possessing  the  greatest  muscular  irritability  (e.  g.  in  birds),  and  vice 
versa — slowest,  therefore,  in  reptiles  and  fishes. 

Pathological  Gondiiions  and  New  Formations  of  Striated  Muscular 

Fibre. 

1.  Hyi^ertropliy  scarcely  occurs  except  in  case  of  the  tongue,  heart, 
and  certain  respiratory  muscles;  though  the  increased  development 

'  From  ar.f,  air,  and  rh^iai,  to  keep  or  hold — an  air-liolder. 


406 


THE    TISSUES. 


Fig.  257. 


induced  by  exercise  is  constantly  seen.  Mere  increased  size  of  the 
original  fibres  may  account  for  the  effects  of  exercise,  but  there  is 
probably  a  growth  of  new  fibres  in  the  former  case.  Wedl  asserts 
that  the  number  of  fibrillas  in  the  fibres  is  increased  in  pathological 
hypertrophies;  and  in  hypertrophied  heart  the  fibres  are  of  a  tawny 
or  rusty-brown  color,  solt,  and  sometimes  anastomosing,  as  seen  in 

Fig.  257.  It  is  also  certain  that 
in  hypertrophied  muscles  the  con- 
nective tissue  between  the  fibres 
sometimes  becomes  hypertrophied. 
2.  Atrophy  of  muscles  is  very 
common,  and  occurs  in  old  age, 
from  lead-poisoning,  from  paraly- 
sis (especially  of  the  tongue),  and 
from  the  development  of  cancer, 
fibrous  tumors,  fat,  &c.,  in  the  sub- 
stance of  the  muscles.  All  causes 
of  general  emaciation  also  pro- 
duce it. 

In  extreme  old   age,    Kolliker 
found  the  fibres  small,  sometimes 

of  an 


Muscular  fibres  in  a  hypertrophied  heart. 
n.  A  subdividing  striated  fibre,  with  dirty  yel- 
low pigment  molecules  in  the  myolemma.  h. 
A  slender  dichotomous  fibre,  c.  Anastomosing 
fibre. — d.  Laminated,  and  e,  smooth,  colloid- 
cell. — Magnified  350  diameters.  {Wedl.) 


not  more  than  3  o'ou 


to 


T5f)C 


Fig.  258. 


inch  in  diameter;  mostly  without 
striae,  and  with  the  fibrillae  indis- 
tinct; and  often  containing  yellow- 
ish or  brown  granules  t2^ot7  of  ^^i  inch  in  diameter,  in  large  quan- 
tity, and  very  many  vesicular  nuclei  with  nucleoli,  together  with  a 
clear  fluid. 

In  'paralyzed  muscles,  Valentin  found  the  transverse  striae  were 

indistinct,  or  had  actually  disappeared,  and  could  not  be  made  to 

appear  by  water,  alcohol,  &c.;  while  the  longitudinal  strice  remained, 

but  resembled  those  of  macerated  muscle. 

Subsequently  the  altered  fibres  disappeared 

in  part,  and  were  partly  replaced  by  fat. 

In  a.  pectoralis  major  atrophied  by  cancer, 
Kolliker  noticed  conditions  similar  to  those 
in  old  age.  He  also  found  cells  in  many  of 
the  fibres  exactly  resembling  the  so-called 
cancer-cells.  Wedl  states  that  in  atrophy 
some  of  the  fibrillre  undergo  absorption. 
The  fibre  also  manifests  a  diminished  co- 
hesion, and  is  easily  lacerated ;  the  myo- 
lemma being  easily  torn  as  well  as  the  my- 
oline  within.     (Fig.  258.) 

3.  In  fait y  degeneration  o^xx\ViSc\QS.,  minute 
fat-globules  are  developed  within  the  myo- 
lemma, in  place  of  the  fibrillae,  which  gra- 
The  fat-drops  also  accumulate  between  the  fibres; 


Atrophy  of  striated  muscular 
filjro.  a.  A  fibre  lorn  across,  b. 
Fibrilla;  hanging  out  — Magnified 
.l.'iO  diameters.  (Wedl.) 


dually  disappear. 


STRIATED    MUSCULAR   FIBRE. 


407 


and,  finally,  the  latter  to  a  greater  or  less  extent  disappear,  and  give 
place  to  areolar  tissue  and  fat-cells.     (Fig.  259.) 

Fig.  259. 


Fatty  degeneration  of  the  heart.  A.  Fibres  talten  from  the  columnje  carnese  of  the  mitral  valves 
of  a  woman  a;t.  30  ;  the  fatty  degeneration  was  scarcely  observable  in  the  ventricle,  where  the  fibres 
still  retained  their  strise.  B.  An  extreme  case  of  fatty  degeneration,  showing  an  entire  replacement 
of  the  myoline  by  oil  globules,  still  retaining  a  linear  arrangement.  From  the  right  ventricle  of  an 
old  gentleman  who  had  Bright's  disease  of  the  kidney  and  pulmonary  phthisis,  and  was  affected 
with  fits  during  the  last  two  years  of  his  life. 


4.  The  condition  of  the  fibres  in  emaciated  muscles  is  unknown. 
Bonders  found  them  more  slender  in  a  frog  which  had  fasted  eight 
months;  which  he  attributed  mainly  to  the  removal  of  the  muscular 
fluid  from  between  the  fibrillae. 

5.  Paleness  of  the  muscles  is  common  in  dropsy,  chlorosis,  para- 
lysis, lead-poisoning,  old  age,  &c.;  the  coloring  matter  being,  per- 
haps, converted  into  the  numerous  brown  and  yellow  granules 
before  mentioned  as  appearing  within  the  myolemma. 

6.  Softening  often  accompanies  paleness.  In  the  former,  the  fibres 
exhibit  no  transverse  strise  nor  fibrils ;  and  readily  break  up  into 
numerous  particles,  or  even  into  a  pultaceous  mass. 

7.  Muscular  fibres  ruptured  in  tetanus,  present  numerous  nodular 
enlargements,  in  which  the  transverse  striee  are  very  closely  approx- 
imated; and  between  them  either  rupture  of  the  fibrilljB,  or  at  least 
a  considerable  stretching  and  disorganization  of  them.  [Bowman) 

8.  Concretions  sometimes  exist  in  muscles.  The  state  of  the  fibres 
has  not  been  investigated. 

9.  True  lone  is  also  sometimes  formed  in  muscles  subjected  to 
prolonged  exercise,  as  the  deltoid  and  some  others.  The  precise 
changes  in  the  fibres  in  this  case  also  are  unknown. 

10.  Of  parasites  in  muscles,  the  Gysticercus  cellulosa,  and  the  Tri- 
china spiralis  are  to  be  mentioned.  These  are  contained  in  distinct 
cysts ;  and  which  are  situated  between  the  fibres. 

11.  Eokitanski  found  a  7ieiu  formation  of  the  striated  muscular 
fibres  in  a  tumor  of  the  testis  of  a  person  eighteen  years  old;  and 
Virchow  also  once  detected  it  in  an  ovarian  tumor. 


4:08 


THE   TISSUES. 


SECTION    II, 
STRUCTURE   OF   THE    MUSCLES. 

The  muscles  consist  of  striated  muscular  tissue,  areolar  tissue, 
vessels,  and  nerves;  and  all  the  longer  fusiform  muscles  (as  of  the 
extremities)  contain  a  considerable  amount  of 
the  white  fibrous  tissue  also. 

The  last-mentioned  muscles  may  each  be 
divided  into — -first,  the  aponeurosis  of  origin  ; 
secondly,  the  tendon  by  which  they  are  inserted 


Fig.  260. 


The  aponeurosis,  belly,  and 
tendon  of  the  fusiform  mus- 
cles (flexors)  on  the  anterior 
aspect  of  the  forearm.  5. 
The  flexor  carpi  radialis ; 
its  aponeurosis  of  origin  is 
seen  at  its  upper  extremi- 
ty, next  its  belly  above  the 
flgnre  5  ;  and  the  tendon 
below  the  latter. 


Transverse  section  of  the  tendon  of  a  calf.  (Magnified  20  diamo* 
ters.)  a.  Primary  fasciculus.  6.  Secondary  fasciculus,  c.  Nuclear 
fibres  not  quite  in  transverse  section,  but  appearing  as  little  streaks 
in  the  former,     d.  Interstitial  connective  tissue.  (Kolliker.) 


into  the  bone  or  other  organ  to  be  moved  by 
them;  thirdly,  the  belly,  or  intermediate  por- 
tion. (Fig.  260.)  Each  of  these  will  be  sepa- 
rately described. 

1.  The  aponeuroses  are  composed  of  white  fibrous  tissue,  and  are 
generally  flattened  into  the  form  of  a  membrane.  Their  structure 
has  already  been  specified  (p.  278,  2). 

2.  The  tend/Jus  are  also  cords  of  white  fibrous  tissue,  like  the 


STRUCTURE   OF   THE   MUSCLES. 


409 


Fig.  262. 


ligaments,  and  containing  very  few  elastic  fibres.  The  fasciculi  of 
the  collagenous  tissue  are  inclosed  in  sheaths  of  areolar  tissue,  which 
thus  forms  delicate  dissepiments  penetrating  the  substance  of  the 
tendons,  as  shown  in  Fig.  261;  then  several  of  the  primary  fasciculi 
(five  to  ten)  are  collected  into  large  bundles — the  secondary  fasci- 
culi. Finally,  the  vessels  are  distributed  in  the  spaces  between  the 
fasciculi  (B^ig.  176);  elastic  fibres  are  also  sent  into  them,  and  the 
whole  is  invested  by  a  sheath  of  areolar  tissue  (p.  278,  1). 

The  elastic  fibres  require  a  particular  description,  however.  In 
a  transverse  section  of  a  tendon,  their  extremities  are  seen  as  dark 
points  in  the  substance  of  the  fasci- 
culi, at  constant  distances  of  tVutj  *^ 
T?  su  of  ^^  i"*^^  apart,  over  the  whole 
section;  and  being  ^^i^^  to  j^U^^ 
of  an  inch  in  diameter.  (Fig.  262.) 
These  are  also  connected  together  in 
various  directions  by  other  finer 
fibres,  5i5^o^  to  g^^oo  of  an  inch  in 
diameter,  so  that  there  is  in  tendons 
an  elastic  network  penetrating  and 
entwining  the  collagenous  tissue. 
These  are  sometimes  seen  in  trans- 
verse sections,  as  lines  radiating  from 
the  coarser  points  before  mentioned. 

Besides,  the  tendons  in  certain 
situations  contain  cartilage-cells,  as 
well  as  even  fat-cells — as  in  the  intercostal  muscles,  the  masseter,  &c. 

The  glistening  appearance  of  the  tendons  depends  upon  their 
transversely  banded  aspect,  as  seen  under  the  microscope ;  and  the 
latter  is  produced  by  the  numerous  curves  in  the  fibres,  which  cor- 
respond with  each  other  throughout  the  fasciculus.  The  curves  are 
doubtless  produced  by  the  elastic  tissue  in  the  fasciculus,  and  there- 
fore at  once  disappear  when  the  tendon  is  stretched. 

The  tendons  consist  of  62.03  per  cent,  of  water  (ChevreuU);  they 
containing  considerably  less,  therefore,  than  the  muscular  tissue 
(p.  396). 

3.  The  belhj  of  the  fusiform  muscles,  and  the  red  portion  of  all 
others,  is  the  only  portion  that  presents  a  peculiar  structure,  as 
alone  containing  the  muscular  tissue;  and  this,  therefore,  will  be 
particularly  described.     It  consists  of — 


Tendon  of  the  tibialis  posticus  (man). 
a.  Primary  fasciculi,  b.  Tiiicker  nucleated 
fibres,  e.  Interstitial  connective  tissue. — 
Magnified  60  diameters.  (KiJlliker.) 


410 


THE   TISSUES. 


1.  The  striated  muscular  fibres. 

2.  Areolar  tissue. 

3.  Bloodvessels,  lymphatics,  and  nerves. 

The  last  three  will  be  described  after  the  two  preceding  topics, 
and  the  connection  of  the  tendons  with  the  bones  and  the  muscular 
fibres,  have  been  disposed  of. 

1.  The  striated  muscular  fibres^  already  described,  are  collected 
together  into  bundles  (fasciculi),  each  inclosed  in  a  sheath  of  areo- 
lar tissue  (internal  perimysium');  these  are  collected  together  into 
larger,  and  the  latter  into  still  larger,  bundles — secondary  and  ter- 
tiary fasciculi;  and  finally  the  whole  is  inclosed  in  a  sheath  of 
areolar  tissue — the  external  perimysium.  These  parts  are  seen  in  a 
transverse  section  of  a  muscle.  Fig.  263.    The  primary  fasciculi  are 

Fig.  263. 


Transverse  section  from  the  rectus  capitis  anticns  major  of  man.    a.  External  perimysium.   6.  Peri- 
mysium internum,     c.  Single  fibre,  and  muscular  fasciculi. — Magnified  350  diameters.  (Kdlliker.) 

72  to  5'^  of  an  inch  thick.  The  secondary  and  the  tertiary  vary 
extremely  in  their  dimensions.  They  are  very  evident  to  the  un- 
aided eye  in  the  coarser  muscles,  especially  the  glutoeus  maximus 
and  the  deltoid. 

The  direction  of  the  fibres  sometimes  corresponds  with  that  of 
the  tendon,  and  sometimes  meets  the  latter  at  an  acute  angle  (semi- 
tendinosus,  &c.).  In  the  former  case  they  are  longer  than  in  the 
latter;  sometimes,  indeed,  extending  through  the  whole  length  of 
the  belly  of  the  muscle — as  in  the  sartorius. 

2.  The  areolar  tissue  constituting  the  muscular  sheaths  (perimysia) 


'  From  Tripi,  around,  and  /t*Sc,  a  muscle.     All  the  interfascicular  areolar  tissue 
taken  together  is  sometimes  called  the  internal  perimysium. 


STRUCTURE   OF  THE   MUSCLES. 


411 


both  supports  and  transmits  the  vessels  and  nerves,  and  also  incloses 
and  supports  the  muscular  fibres  while  in  action.  The  external 
perimysium  contains  more  elastic  tissue  than  the  internal;  and,  in 
estimating  its  function,  it  may  be  regarded  as  a  semi-elastic  mem- 
brane. Liebig  found  about  5.6  per  cent,  of  the  muscle  to  be  con- 
nective tissue;  Von  Bibra  but  2.2  per  cent.  There  is  proportionally 
more  in  the  calf  than  in  the  ox. 

In  all  muscles,  but  especially  the  laxer  in  structure,  a  certain 
number  of  adipose  cells  also  are  found  in  the  areolae  of  the  peri- 

mysia ;    and   these  frequently  contain   beautiful 

•^  1  J  pj     264. 

crystals  of  margaric  acid  (p.  298).    In  fat  persons 

these  cells  are  quite  abundant  among  the  primi- 
tive fasciculi  even. 


Connections  of  the  Tendons  at  their  Extremities. 

The  tendons  are  connected  at  one  extremity 
with  the  belly  of  the  muscle  (or  the  part  contain- 
ing the  muscular  fibres),  and  at  the  other  with  the 
bones  or  other  parts  moved  by  the  muscles. 

I.  The  tendons  are  connected  with  the  muscu- 
lar fibres  in  two  ways:  1.  When  the  latter  lie  in 
the  direction  of  the  axis  of  the  muscle,  and  thus 
extend  through  the  whole  length  of  the  belly  of 
the  latter,  they  pass  directly  into  the  fibres  of 
the  white  fibrous  tissue  in  the  tendon,  in  such  a 
way  that  there  is  no  sharply  defined  limit  be- 
tween the  two  tissues;  the  tendinous  fibre  being 
nearly  equal  in  size  to  the  muscular,  and  appear- 
ing to  be  actually  continuous.^  (Fig.  264.)  2.  But 
when  the  muscular  fibres  join  the  tendons  at  an 
acute  angle — as  in  the  penniform  muscles — the 
microscopic  conditions  are  entirely  different ; 
there  being  an  abrupt  limit  between  the  two  tis- 
sues. Here  the  muscular  fibres  end  neatly  in  an 
obliquely  truncated  extremity,  with  a  projecting 
surface,  slightly  conoidal,  or  sometimes  per- 
ceptibly attenuated,  and  always  rounded ;    and 


A  muscular  fibre,  {a), 
from  one  of  the  inter- 
nal intercostal  muscles 
of  man,  continuous  into 
a  tendinous  fasciculus 
(ft),  into  -vrhich  it  passes 
without  any  defined  li- 
mit.— Magnified  350  dia- 
meters. {KCUiker.) 


'  Dr.  Leidy  has  described  a  double  spiral  arrangement  of  the  tendinous  fibres 
around  the  myolemma. 


412  THE   TISSUES. 

attached  tit  a  more  or  less  acute  angle  to  the  surfaces  of  the  tendons 
and  aponeuroses,  and  on  the  borders  of  the  former.    (Fig.  266.) 

Fig.  265. 


"  / 

Disposition  of  the  muscular  fibres  at  their  oblique  insertion  into  the  tendon  of  the  gastrocnemius 
of  man.  a.  A  portion  of  the  tendon  cut  longitudinally,  b.  Muscular  fibres,  with  slightly  conical  or 
truncated  extremities,  affixed  in  small  depressions  on  the  inner  aspect  of  the  tendon ;  with  the  sheath 
of  which  the  perimysium  internum  (c)  is  connected. — Magnified  330  diameters.    (Kulliker.) 

Still,  the  connection  is  of  the  most  intimate  kind ;  the  extremities 
of  the  fibres  being  inserted  into  minute  pits  in  the  surface  of  the 
tendon,  while  the  perimysia  interna  are  continuous  with  the  areolar 
sheaths  of  the  fasciculi  of  the  tendon.  In  muscles  which  have  been 
boiled,  the  sacciform  blind  extremity  of  the  myolemma  may  be 
seen.  In  no  case  does  Kolliker  find  the  tendinous  fibres  connected 
with  the  myolemma  merely,  as  stated  by  Keichert. 

The  preceding  arrangement  obtains  whenever  muscular  fibres  and 
tendons  meet  obliquely  (all  penniform  and  semi-penniform  muscles), 
and  whenever  tendons  of  insertion  commence  as  membranous  ex- 
pansions (soleus,  gastrocnemius,  &c.).  And  even  where  tendons 
and  aponeuroses  join  the  muscle  in  a  straight  line,  there  is  a  greater 
or  less  number  of  fibres  which  are  connected  in  this  way,  though 
most  undergo  a  transition,  as  described  at  the  commencement  of  the 
preceding  paragraph. 

II.  The  tendons  are  connected,  at  their  distal  extremity  or  inser- 
tion, with  bones,  cartilages,  fibrous  membranes  (sclerotica,  tendinous 
fasciae),  ligaments,  and  synovial  membranes  (subcruralis,  &c.).  The 
aponeuroses  of  origin  are  also  connected  with  the  same  parts ;  and 
their  manner  of  connection  is  therefore  the  same  as  that  of  the  ten- 
dons, to  be  described. 

The  tendons  are  connected  with  the  bones  and  cartilages,  either 
first,  directly;  or,  secondly,  indirectly — i.e.  through  the  intervention 
of  the  periosteum  and  the  perichondrium. 

1.  In  the  former  case,  the  periosteum  is  entirely  wanting  where 
the  muscle  is  inserted,  and  the  tendinous  fibres  and  fasciculi  rest  at 


VESSELS    OF   THE    MUSCLES. 


413 


Fig.  266. 


an  acute  or  a  right  angle  directly  on  the  surface  of  the  bones,  being 
blended  with  all  its  elevations  and  depressions.  Close  to  the  bones, 
the  tendons  frequently  contain  delicate  isolated  cartilage-cells.  (Fig. 
224.)  Sometimes  the  tendinous  fibres  are,  next  the  bone,  entirely 
incrusted  with  calcareous  salts,  in  the  form  of  granules  (ossified). 
This  kind  of  direct  connection  obtains  in  the  tendo-Achillis,  the 
tendons  of  the  quadriceps  femoris,  pectoralis  major,  latissimus  dorsi, 
deltoid,  psoas,  iliac,  glutsei,  &c.  (p.  346). 

2.  In  case  of  indirect  connection  of  the  tendons,  their  fasciculi  and 
fibres  are  continuous  with  those  of  the  periosteum,  fasciae,  fibrous 
membranes,  &c.,  respectively. 

The  insertion  of  muscles  into  the  areolar  tissue  of  the  skin  and 
mucous  membranes,  without  the  interven- 
tion of  tendons,  should  be  alluded  to  here. 
This  is  best  seen  in  the  tongue  and  the 
facial  muscles  of  mammals.  Here  the  mus- 
cular fasciculi  lie  in  the  subcutaneous  areo- 
lar tissue,  maintaining  the  same  diameter 
till  they  nearly  reach  their  insertions. — 
Then  they  divide  into  several  branches, 
each  tapering  to  a  conical  extremity,  or  di- 
viding into  a  number  of  delicate  pointed 
processes.  In  either  case,  the  fibres  gra- 
dually or  suddenly  lose  their  striation,  and 
pass  into  the  nucleated  bands  of  the  white 
fibrous  tissue.  No  myolerama  can  be  seen 
in  the  branched  ends  of  the  muscles,  but  the 
white  fibrous  tissue  is  directly  continuous 
with  the  matrix  of  the  muscular  fibres. 


The  Vessels  of  the  Muscles. 
The  arterial  trunks  reach  the  muscles  in 
an  oblique  or  transverse  direction,  and  then 
subdividing,  run  in  the  perimj^sia  interna  in 
an  arborescent  manner,  and  at  an  acute  or 
obtuse  angle,  so  that  every  part  of  the  mus- 
cle is  supplied  by  them.  The  minutest  arte- 
ries and  veins  usually  run  parallel  to  the 
muscular  fibres,  between  which  they  form  a 
plexus,  so  characteristic  as  never  to  be  mis- 
taken after  being  once  seen.  (Fig.  266.) 


Capillaries  of  a  small  fascicu- 
lus of  muscular  fibres  from  the 
neck  of  the  dog.  a.  Terminal 
tTrig  of  the  artery,  r.  Terminal 
twig  of  the  vein.  p.  Plexus  of 
capillaries,  e.  Single  muscular 
fibre,  to  show  the  relative  size 
and  direction  of  tho.^e  to  which 
the  capillaries,  here  represented, 
are  distributed. 


414 


THE   TISSUES. 


Fig.  267. 


The  longitudinal  vessels  of  the  network  lie  between  the  fibres,  and 
the  transverse  ones  unite  in  various  ways  with  the  former.  Thus 
each  separate  fibre  is  surrounded  on  all  sides  by  minute  vessels, 

and  hence  abundantly  supplied  with 
blood.  The  longitudinal  vessels  are 
seen  in  a  transverse  section  of  a  fasci- 
culus (Fig,  267)  lying  in  passages  in 
the  internal  perimysium. 

The  capillaries  of  muscle  are  among 
the  smallest  in  the  human  body,  their 
diameter  being  often  less  than  that  of 

Transverse  section  of  three  fibres  of     the    blood-COrpUSClcS     themSClveS.        lu 

the  pectoralis  major,  when  filled  with 
blood,  they  measure  goV^  to  ^oV^  of 
an  inch;    and,  when  emptv,  ^^'tttt  to 


the  dried  pectoral  muscle  of  the  teal 
(querquedula  crecca),  treated  with  weak 
citric  acid  ;  showing  the  round  refract- 
ing particles  separated  from  one  another. 
The  cut  edge  of  the  tubular  sheath  (in- 
ternal perimysium)  of  each  fibre  is  also 
seen,  as  well  as  the  capillary  vessels  (a) 
in  the  intervals. 


inch;    and,  when  empty,  ^gV^ 
5(70  0  of  ^^  inch.  {KoUiker.) 


The  tendons  present  no  bloodvessels 

in   the   innermost   portions,   and    the 

smallest  are  entirely  non-vascular  internally.     The  latter,  however, 

present  vessels  in  the  sheath  inclosing  them ;  and  the  largest  have 

vessels  both  in  the  sheath  and  in  the  deeper  layers.  (Fig.  176.) 

Very  few  'lymphatic  vessels  are  found  in  the  muscles.  Indeed, 
the  smaller  (omo  hyoid,  subcrural,  &c.),  have  none  at  all,  either  in 
their  substance  or  upon  their  surface ;  and  among  the  largest  mus- 
cles, it  is  only  in  some  that  solitary  lymphatics,  gV  to  -^^  of  an  inch 
n  diameter,  are  seen  accompanying  the  bloodvessels.  It  is  proba- 
ble that  these  do  not  run  among  the  fasciculi,  but  in  the  more  vas- 
cular perimysia  between  the  larger  and  laxer  subdivisions;  and 
especially  when  the  latter  contains  adipose  tissue,  and  is  therefore 
soft,  as  in  the  glutaeus,  and  in  the  superficial  layers  of  the  muscles. 

No  lymphatics  have  yet  been  found  in  the  tendons,  aponeuroses, 
or  the  synovial  capsules  of  the  muscular  system.  They  may,  how- 
ever, exist  in  the  areolar  tissue  under  the  latter ;  as  in  the  subse- 
rous areolar  tissue  of  the  joints. 


Nerves  of  the  Muscles. 

The  nerves  of  the  muscles  come  into  contact  with  the  fibres  only 

at  a  few  points  comparatively,  and  not  throughout  their  length. 

The  trunks  divide  pretty  suddenly  on  entering  the  muscles,  into 

several  anastomosing  subdivisions,  which  give  ofl"  still  smaller  loops 


NERVES   OF   THE   MUSCLES. 


415 


inclosing  the  fasciculi,  and  passing  among  the  individual  fibres. 
(Fig.  268.)  Whether  there  are  also  free  terminations  of  the  nerve- 
fibres  in  man,  besides  these  loops,  such  as  exist  in  the  lower  animals, 
is  not  certainly  determined. 


Form  of  the  terminating  loops  of  the  nerves  of  the  muscles. 

The  trunks  entering  the  muscles  are  composed  mostly  of  the  thick 
(medullated)  nerve  fibres;  there  being  only  twelve  of  the  finer,  on 
an  average  to  one  hundred  of  the 


larger 


Fig.  269. 


{Yollcmann')  In  the  in- 
terior of  the  muscle  they,  how- 
ever, become  smaller ;  so  that  the 
fibres  of  the  terminal  plexus  are 
only  -x^U-Q  to  4gVo  of  an  inch  in 
diameter.  Sometimes  the  gra- 
dual attenuation  can  be  seen  un- 
der the  microscope,  showing  that 
sometimes  at  least  this  diminu- 
tion is  not  due  to  division.  Kol- 
liker  finds  them  to  present  at  last 
the  appearance  of  the  so-called 
sympathetic  fibres ;  becoming 
pale,  with  a  simple  contour  line 
disposed  to  form  varicosities. 
Thus,  though  no  neurilemma 
could  be  distinguished,  the  dark 
border  shows  that  they  are  not 
free  axis-cylinders,  or  non-medul- 
lated  fibres,  such  as  are  seen  in  other  terminations  of  nerves 


Divisions  of  the  nerve-fibres  in  muscle.  (Mag- 
nified 350  diameters.)  A.  Double  division  from 
the  omohyoid  muscle  in  man.  o,  a,  a.  Neuri- 
lemma. B.  Division  of  a  nerva  from  a  facial 
muscle  of  the  rabbit  into  three  apparently  pointed 
twigs.  {KoUiker.) 


416  THE   TISSUES. 

It  is  also  certain  that  divisions  of  tlie  nerve-fibres  occur  in  tlie 
muscles  of  man,  though  thej  are  rare  and  detected  with  difficulty. 
(Fig.  269.)     Their  relation  to  the  loops  is  still  to  be  made  out. 

In  many  of  the  small  muscles  the  extent  of  space  to  which  the 
nerve-fibres  are  distributed  is  very  limited.  In  a  portion  of  the 
superior  belly  of  the  omo-hyoid,  three  inches  long,  the  portion  to 
which  the  nerves  are  distributed  is  not  more  than  five  to  six  lines 
in  length.  The  trunk  of  the  nerve  enters  in  the  middle  of  the 
transverse  axis  of  the  muscle,  and  divides  into  two  primary  branches, 
one  passing  to  the  right  and  the  other  to  the  left  border  of  the  mus- 
cle. Each  of  these  gives  off  numerous  anastomosing  branches  of 
all  sizes,  thus  supplying  the  entire  thickness  of  the  muscle  from 
the  most  superficial  to  the  deepest  layers.  The  rest  of  the  muscle 
usually  presents  a  complete  deficiency  of  nerves.  The  same  con- 
ditions obtain  in  the  lower  belly  of  the  omohyoid,  in  the  sterno- 
hyoid, sterno-thyroid,  subcruralis,  &c.  It  appears  to  be  true  in 
respect  to  the  larger  muscles  also,  that  their  separate  portions  are 
in  connection  with  the  nervous  plexus,  only  at  a  point  of  limited 
extent.  Whether  the  muscular  fibres  are  in  contact  with  nerves 
only  at  a  single  point  when  the  former  are  of  the  greatest  length 
(as  in  the  sartorius,  latissimus  dorsi,  &c.),  is  not  yet  decided. 

Nerves  are  also  found  accompanying  the  vessels  of  muscles 
(nervi  vasorum);  but  these  present  no  peculiarities.  They  are  com- 
posed of  the  finest  fibres  alone,  and  are  distributed  to  the  arteries 
and  veins  (seldom  to  the  smallest),  but  not  to  the  capillaries.  How 
they  terminate  is  still  unknown.  Some  fibres  also  from  the  muscu- 
lar plexus  before  described,  occasionally  join  those  of  the  vessels. 

The  larger  tendons  contain  the  vascular  nerves  only,  and  the 
smaller  none  at  all.  The  fasciae  and  the  sheaths  of  the  tendons,  as 
well  as  the  synovial  capsules  (bursas  mucosae),  contain  none. 

Peculiarilles  in  the  Lower  Animals. — In  the  invertehrata^  the  nerve- 
fibres  are  known  to  terminate  in  the  muscles  by  free  extremities, 
which,  after  expanding,  are  inserted  into  the  muscular  fibres.  The 
divisions  are  sometimes  trifid.  In  them,  also,  every  muscular  fibre 
appears  to  have  a  nerve-fibre  distributed  to  it;  and  often  accompa- 
nying it  for  a  considerable  distance,  and  forming  loops  or  spirals 
around  it.  In  the  amjildhia  the  divisions  are  multiple  (Fig.  270), 
and  even  ^eight-fold.  [Wagner.)  The  ultimate  filaments  are  pale 
and  have  a  simple  contour  line.  They  do  not  penetrate  the  mus- 
cular fibre,  but  are  merely  closely  applied  to  it,  either  obliquely, 
transversely,  or  longitudinally,  for  some  distance;  becoming  in  all 


ACCESSORY   ORGANS   OF   THE   MUSCLES.  417 

cases  attenuated  to  a  sharp  point,  frequently  as  fine  as  a  fibre  of  the 
white  fibrous  tissue.  {KoUiker.) 

In  the  mylo-hyoideiLs  muscle  of  the  frog,  Reichert  found  160  to 
180  fibres,  and  the  nervous  trunks  to  contain  "  7  to  10  fibres,  ulti- 
mately forming  from  290  to  340  filaments  by  continual  division,  or 
more  than  one  for  each  muscular  fibre." 

Fig.  270. 


Divisions  of  nerve-fibres  in  a  small  tvrig  from  tlie  cutaneous  thoracic  muscle  of  the  frog.     a.  Bifur- 
cation,   h.  Threefold  division. — Magnified  350  diameters.     (KiJllil-er.) 

Accessory  Organs  of  the  Muscles. 
Under  this  head  are  included : — 

1.  The  muscular  envelops,  or  fascias. 

2.  Ligaments  of  the  tendons. 

3.  Tendinous  sheaths  and  the  synovial  sacs  (bursas  mucosae). 

4.  Fibro-cartilages  and  sesamoid  bones. 

1.  The  Muscular  Envelops  {Fasciee\  &c. 
The  fascife  are  fibrous  membranes  surrounding  single  muscles 
(sartorius,  &c.),  or  entire  groups  of  muscles,  with  their  tendons. 
The  deep  fascial  of  the  extremities  (femoral,  brachial,  and  ante-bra- 
chial  aponeuroses,  &c.),  are  illustrations.  These  also  give  insertions 
to  muscles,  and  thus  become  tendons  (tensor  vaginas  femoris),  or 
27 


418  THE  TISSUES. 

give  origin  to  tliem,  and  thus  become  aponeuroses;  e.  g.  the  inter- 
osseous membrane  of  the  forearm  and  leg.  They  are  also,  in  cer- 
tain parts,  thickened  into  ligaments  (as  on  the  dorsal  aspect  of  the 
carpus),  to  retain  the  tendons  in  place.  In  all  these  cases,  they  pre- 
sent the  character  and  structure  of  tendons  and  ligaments. 

In  some  instances,  however,  the  distinct  muscular  sheaths  are 
formed  of  areolar  tissue,  and  are  hence  extensible,  and  allow  of  a 
considerable  amount .  of  motion  of  the  muscle  within  them ;  e.  g. 
sterno-cleido-mastoideus,  and  other  muscles  manifesting  a  consider- 
able amount  of  motion  under  the  skin. 

N 

2.  7%e  Ligaments  of  the  Tendons. 

These  retain  the  tendons  in  their  place  in  certain  parts;  e.  g.  the 
dorsal  and  palmar  ligaments  of  the  carpus,  which  retain  the  exten- 
sors and  the  flexors  of  the  fingers — and  the  corresponding  ligament 
of  the  foot. 

Small  bundles  of  white  fibrous  tissue  also  strengthen  the  tendin- 
ous sheaths  next  to  be  described,  as  minuter  ligaments. 

All  the  ligaments,  mentioned  under  this  head,  present  the  struc- 
ture and  character  of  those  in  relation  with  joints  (p.  278),  and  con- 
tain fewer  vessels  than  the  tendons. 

3.  Tlie  Tendinous  Sheaths  and  Synovial  Sacs. 

The  sheaths  of  the  tendons  (as  of  the  flexors  and  extensors  of 
the  fingers  and  toes)  are  usually  described  as  closed  serous  mem- 
branes, of  which  one  portion  invests  the  tendon  and  the  other  lines 
the  special  canal  in  which  it  glides  to  and  fro.  Kcilliker,  however, 
finds  that  no  membrane  at  all  exists  on  the  greater  part  of  the  sur- 
faces hitherto  supposed  to  be  covered  by  it.  Fimbriated  processes 
are,  however,  found  projecting  here  and  there  into  the  cavity  con- 
taining the  synovial  fluid,  and  from  which  the  latter  is  doubtless 
secreted.  These  processes  are  very  vascular,  like  those  of  the  syn- 
ovial capsules  of  the  joints  (p.  345). 

The  hursoi  mucosae,  or  synovial  capsules  of  the  muscles,  invest  the 
opposed  surfaces  of  muscles  and  bones,  as  under  the  psoas,  iliacus, 
deltoid,  gluteus  maximus,  &;c.  (p.  195).  These  also  appear  in  the 
form  of  closed  sacs,  but  are  usually  not  everywhere  constituted  of 
a  serous  membrane,  any  more  than  the  preceding  tendinous  sheaths. 
In  both,  the  epithelium  is  almost  never  complete;  and  both  are, 
therefore,  to  be  classed  with  the  synovial  capsules  of  the  joints. 


PHYSICAL   PROPERTIES   OF   THE   MUSCLES.  419 

Cartilage-cells  are,  however,  to  be  found  in  the  textures  entering 
into  the  synovial  capsules  of  the  muscles;  though  genuine  carti- 
lage has  not  yet  been  found  on  the  opposed  and  gliding  surfaces  of 
muscles  and  bone,  except  in  case  of  the  cuboid  bone. 

4.  Fibro- Cartilages  and  Sesamoid  Bones. 

A  layer  of  fibro-cartilage  is  found  covering  the  grooves  on  bones, 
in  which  tendons  glide  (tibialis  posticus,  peroneus  brevis,  &c.) ;  and 
frequently  the  tendon  also  is  thickened  by  a  layer  of  the  same 
tissue  on  the  surface  which  glides  on  the  bone.  But  on  the  cuboid 
bone,  under  the  tendon  of  the  peroneus  longus,  is  a  layer  of  true 
cartilage,  3'g  to  ^^  of  an  inch  thick, 

Fibro-cartilages  also  exist  normally  in  the  flexor  tendons  of  the 
fingers  and  toes;  their  free  surface  presenting  towards  the  articu- 
lations. If  they  become  ossified,  they  are  called  sesamoid  hones  (e,  g. 
in  flexor  tendon  of  thumb,  great  toe,  in  ligamentum  patellae,  &c,). 
These  are  covered  by  a  thin  layer  of  cartilage  next  the  joint,  and 
blend  with  the  tendinous  structure  on  the  other  side. 

Physical  Properties  of  the  Muscles. 

In  the  muscular  tissue  of  man  {i.  e.  including  the  perimysia,  &c,), 
there  are  usually  72.56  to  74.45  per  cent,  of  water,  and  25.55  to 
27,44  per  cent,  of  solid  residue.  The  analysis  of  the  latter  has  been 
given  on  page  396,  where  the  highest  extreme  of  the  water  is  put 
at  80  per  cent. 

The  bright  red  color  of  the  muscles  has  already  been  accounted 
for  (p,  397). 

The  muscles  are  capable  of  being  stretched — even  the  tendons 
are  not  totally  inextensible  in  their  natural  condition  (p.  409) — and 
also  manifest  a  certain  degree  of  the  physical  property  of  elasticity. 
This  is  exemplified  by  the  return  to  their  former  condition  of  the 
muscles  of  the  abdomen,  after  being  stretched  during  pregnancy 
and  by  dropsical  accumulations.  The  muscles  even  of  a  dead 
animal  still  return  thus  after  being  stretched,  though  they  do  not 
altogether  resume  their  original  form,  and  therefore  are  more  rea- 
dily torn.  Still,  such  a  slender  muscle  as  the  gracilis  may  support 
a  weight  of  eighty  pounds  after  death,  without  breaking.  Kolliker 
thinks  the  rigor  mortis  is  produced  by  an  increase  of  elasticity,  and 
is  not  a  vital  phenomenon,  as  the  author  of  the  present  work  has 


420  THE   TISSUES. 

considered  it  (p.  405).     The  elasticity  doubtless  inheres  in  part  iu 
the  rayolemmata  of  the  muscles,  since  they  resemble  elastic  tissue. 

Physiological  Remarhs. 

The  use  of  the  muscles  depends  on  the  vital  property  inherent 
in  the  muscular  fibres — contractility^  or  spontaneous  shortening — 
producing  motion  in  the  parts  (bones  especially)  with  which  they 
are  connected.  The  tendons  and  aponeuroses  only  serve  to  trans- 
mit the  motor  force  generated  in  the  muscular  fibres.  Hence  the 
tendons  of  the  flexors  and  extensors  of  the  fingers  and  toes  are 
elongated,  in  order  to  remove  the  belly  of  the  muscle  to  a  distance, 
and  secure  beauty  of  proportion  in  the  limbs.  During  contraction, 
the  fibres  shorten  in  a  rectilinear  direction,  but  do  not  undergo  any 
considerable  condensation.  Their  tenacity  is,  however,  much  in- 
creased; so  that  the  tendon  gives  way  rather  than  the  belly  of  the 
muscle,  if  rupture  occurs  from  violent  contraction — as  in  the  tendo- 
Achillis,  &c.  Ordinarily,  only  a  part  of  the  fibres  in  a  muscle  con- 
tract at  the  same  time  (p.  402).  Thus  the  full  strength  of  a  muscle 
is  seldom  exerted,  and  usually  only  under  the  highest  excitement — 
as  in  mania,  &c. 

It  has  been  stated  that  the  muscles  ordinarily  contract  in  conse- 
quence of  a  stimulus  communicated  to  them  by  the  nerves  (p.  402). 
Of  the  nature  and  precise  mode  of  their  action,  we,  however,  know 
nothing;  though  it  may  be  inferred  that,  in  the  veriebrata^  the 
nervous  influence  acts  from  a  certain  distance,  since  the  nerve- 
fibres  touch  the  muscular  fibres  only  at  a  few  points,  and "  never 
penetrate  into  their  interior  (p.  416). 

The  intrinsic  contractile  force  of  a  muscle  depends  not  on  its 
length,  but  on  the  number  and  size  of  its  fibres,  or  its  transverse 
sectional  area.  The  extent  of  motion,  however,  at  the  point  of  in- 
sertion, depends,  cceteris  paribus^  on  the  length  of  the  fibres,  and  can 
never  exceed  three-fourths  to  five-sixths  of  the  length  of  the  belly 
of  the  muscle,  since  no  individual  fibre  shortens  more  than  in  this 
proportion  (p.  402).  When,  however,  the  fibres  are  short,  a  com- 
pensation in  respect  to  the  amount  of  motion  of  the  part  to  be 
moved  may  be  secured  by  having  the  insertion  of  the  muscle  nearer 
to  the  extremity  of  the  bone  to  be  moved  by  it — e.  g.  the  semi-mem- 
branosus,  as  compared  with  the  semi-tendinosus.  The  available  or 
effective  force  of  a  muscle  depends  much  on  its  relations  to  the  part 
into  which  it  is  inserted.    Most  of  the  muscles  are  inserted  in  such 


DEVELOPMENT   OF   THE    MUSCLES.  421 

a  way  as  to  act  at  a  mechanical  disadvantage  (?',  e.  so  as  to  act  at 
first  nearly  parallel  to  the  surface  of  bones  they  move,  or  near  the 
extremities  of  the  latter).  Thus  their  effective  is  much  less  than 
their  intrinsic  force.  E.  g.  the  intrinsic  force  of  the  deltoid  has 
been  estimated  at  1,000  pounds;  while  its  available  force  is  perhaps 
not  more  than  50  pounds.  As  a  compensation  for  this  loss  of  force, 
greater  velocity  and  extent  of  motion  of  the  part  are  secured  with 
a  given  amount  of  shortening  of  the  muscular  fibres. 

The  tonicity  of  the  muscles  has  been  spoken  of  on  page  403. 

The  muscles  possess  sensibility,  though  of  a  peculiar  kind ;  they 
becoming  painful  and  sensitive  to  pressure  after  long-continued  ac- 
tion, and  after  being  affected  with  cramps  or  spasms;  while  scarcely 
any  sensation  is  excited  by  punctures,  burns,  and  incisions  into  their 
substance.  They  also  possess  a  delicate  sense  of  feeling  for  their 
own  state  of  contraction,  and  estimate  very  minute  variations  in  the 
force  with  which  they  act.  It  is  this  kind  of  sensibility  (called  the 
muscular  sense)  which  enables  us  to  judge  of  the  weight  of  objects. 
The  sense  of  fatigue  is  also  peculiar  to  the  muscles.  It  has  already 
been  shown  that  the  muscles  contain  but  few  sensitive  nerve-fibres 
(p.  415) — enough,  probably,  to  give  merely  the  slight  impressions 
normally  characterizing  the  muscles  in  ordinary  circumstances; 
while  they  may  also  give  rise  to  pain,  even,  when  compressed  for  a 
time  during  their  contraction. 

The  muscles,  during  their  contraction,  elicit  a  peculiar  sound,  of 
a  silvery  character,  and  which  somewhat  resembles  the  rumbling  of 
distant  carriage- wheels.  This  is  probably  produced  by  modifica- 
tions in  the  circulation,  as  well  as  by  the  changes  occurring  in  the 
fibres  themselves. 

Heat  is  also  developed  by  muscles  during  contraction,  as  has 
already  been  explained  (p.  402);  oxygen  being  absorbed  and  car- 
bonic acid  being  given  off  by  them  at  the  same  time. 

Development  of  the  Muscles. 
The  manner  in  which  the  striated  muscular  fibres  are  developed, 
has  already  been  explained  (p.  399).  The  muscles  are  not  evident 
as  distinct  organs  in  the  human  foetus  before  the  end  of  the  second 
month,  and  can  then  be  seen  only  under  the  microscope ;  and  the 
tendons  cannot  be  distinguished  from  the  other  portions.  In  the 
tenth  to  the  twelfth  week  they  are  more  distinct ;  and  the  tendons 


422 


THE    TISSUES. 


maj  also  be  distinguished,  as  somewliat  clearer  but  still  transparent 
streaks. 

In  the  fourth  month,  both  the  muscular  tissue  and  the  tendons 
are  more  distinct,  the  former  being,  on  the  trunk,  of  a  light  reddish 
color.  At  birth,  the  muscular  fibres  are  still  softer  and  paler,  and 
the  tendons  more  vascular  and  less  white  than  they  subsequently 
become. 

The  elementary  parts  of  the  tendons  are  never  formed  earlier 
than  those  of  the  muscular  portion.     Indeed,  they  cannot  be  recog- 
nized as  fasciculi  of  the  white  fibrous  tissue  till 
about  the  fourth  month,  though  the  muscular 
fibres  are  quite  distinct  at  the  eighth  to  the  ninth 


Fis.  271. 


week.    Beino-  ^^i 


o   10  0  00 


to 


.g'o0  of  an  inch  in  diame- 


ter at  the  fourth  month,  the  fasciculi  (at  first  con- 
taining no  distinct  fibres)  become  goV(j  to  ^g'^o  ^^ 
an  inch  in  diameter  at  birth.  At  this  time,  also, 
their  fibres  are  distinct,  and  the  fine  elastic  fibres 
are  developed  between  the  fasciculi  from  special 
fusiform  formative  cells.  Fig.  271  shows  the  wavy 
appearance  of  the  fasciculi  at  birth,  and  also  the 
elongated  nuclei  lying  upon  and  among  them, 
from  which  the  elastic  fibres  are  probably  deve- 
loped.    (See  also  Figs.  261-2.) 

In  the  adult,  the  fasciculi  of  the  tendons  are 
2  (J  0  7  to  yg'o^  of  an  inch  in  diameter.  Their  rela- 
tive size,  therefore,  in  the  foetus  at  four  months, 
the  new-born  child,  and  the  adult,  are  as  1  :  1.8  :  6; 

of  the  fine  elastic  fibres,  go  that  the  growtli  of  the  tcudous,  after  birth  at 
least,  seems  due  to  the  increased  thickness  and 

elongation  of  their  fasciculi ;  while  their  number  also  is  constantly 

increased  during  foetal  life. 


From  the  tendo-Achillis 
of  a  new-born  child,  mag- 
nified 2."j0  diameters ;  and 
treated  with  acetic  acid, 
to    show   the    formation 


Pathological  States  of  the  Muscles  and  their  Accessories. 

The  pathological  states  of  the  striated  muscular  tissue  have  already 
been  specified  (p.  406);  of  which  hypertrophy,  atrophy,  paralysis, 
fatty  degeneration,  and  softening  are  the  most  imjiortant. 

The  most  common  pathological  state  of  the  tendons  and  aponeu- 
roses is  atrophy,  consequent  on  the  same  condition  of  the  mus- 
cular fibres,  and  disease  of  the  muscle.  The  tendons  also  become 
shortened  in  case  of  talipes  (club-foot)  and  other  deformities;  since 
changes  in  the  relations  of  the  bones  have  brought  the  points  of  in- 


NERVOUS   TISSUE.  423 

sertion  of  the  tendons  abnormally  near  to  the  belly  of  the  muscle. 
Hence  the  propriety  of  dividing  the  tendons,  and  bringing  the  bones 
into  their  normal  relations,  in  such  cases;  after  which,  the  former 
assume  the  normal  length  by  a  new  formation  of  collagenous  tissue 
between  the  divided  extremities. 

The  vaginal  sheaths  of  tlie  tendons,  especially  of  the  extensors  of 
the  fingers,  are  liable  to  dilatations  and  accumulations  of  the  syno- 
vial fluid,  forming  protrusions  called  ganglia.  The  most  common 
seat  of  the  ganglion  is  on  the  dorsum  of  the  wrist. 

The  synovial  sacs  of  the  muscular  system  (bursas  mucosae)  are  also 
liable  to  inflammation,  and  consequent  distension,  from  the  fluid 
they  contain.  The  affection  usually  termed  "housemaid's  knee"  is 
an  inflammation  of  a  synovial  sac,  not  connected  with  the  muscular 
system,  but  existing  between  the  patella  and  the  skin  covering  it. 


CHAPTER    X. 


NERVOUS   TISSUE,  AND   THE   STRUCTUEE   OF  THE  NERVOUS 

SYSTEM. 

SECTION   I. 
THE   NERVOUS   TISSUE. 

Two  forms  of  the  nervous  tissue  are  to  be  described : — 

I.  The  fibrous  or  tubular  nerve-tissue. 
II.  The  vesicular  or  cellular  (nerve-cells). 

I.  Fibrous  or  Tubular  Nerve-Tissue. 

This  form  of  nerve-tissue  is  termed  tubular,  because,  when  de- 
veloped in  the  highest  degree,  it  presents  the  form  of  tubes  inclosing 
a  fibre.  In  other  cases,  however,  the  tube  is  wanting,  and  then  the 
term  "fibrous"  is  more  appropriate.  The  latter  are  far  more  minute 
than  the  former ;  and  hence  these  two  forms  have  been  called  by 
Kcilliker  the  coarse  and  the  fine  nerve-fibres.  (Fig.  272.)  There  is 
also  a  medium  size,  averaging  about  the  4^Vo  of  ^.n  inch  in  dia- 
meter. 

The  coarsest  nerve-fibres  are  even  js'^^j  ^^  ^^  inah.  in  diameter; 
while  the  finest  have  only  j'^  this  diameter,  or  24^^^  of  an  inch. 


424 


THE   TISSUES. 


The  length  of  the  nerve-fibres  also  varies  extremely ;  since  they 
have  one  extremity  in  the  part  where  they  are  distributed,  while 

the  other  enters  the  ence- 
^^*       ■  phalon  or  spinal  cord  (to 

constitute  their  white  or 
fibrous  portions),  or  termi- 
nates in  ganglia. 


1.  The  Coarse  {large)  Nerve- 
Fibres. 
It  is,  of  course,  impossible 
to  draw  any  precise  line 
between  the  coarse  and  the 
medium  nerve-fibres,  since 
all  grades  of  size  are  found 
between  their  extremes  of 
Ts'uTJ  ^f  ^^  v^Q^  as  the  dia- 
meter of  the  coarsest,  and 
as  that  of  the  finest 
Nor  is  it  of  any 
importance  that  the  inter- 
mediate should  be  distin- 
guished as  such;  since  they 
appear  to  present  no  pecu- 
liarity in  structure  or  func- 
tion. Kcilliker,  however, 
mentions   as   coarse   fibres 


24  ouu 
fibres. 


Nervo-filires.  1.  From  tlie  dog  and  rabbit,  in  their  na- 
tural condition :  «,  fine  ;  6,  of  medium  thickness  ;  c.  coarse 
fibre  from  the  peripheral  nerves.  2.  From  the  frog,  with 
the  addition  of  serum  :  a,  drop  of  the  contents  expressed  ; 
6,  axis-fibre  within  the  drop  continued  into  the  tube. 
3.  From  the  spinal  cord  of  man  ;  recent,  with  serum  add- 
ed :  a,  neurilemma  ;  6,  medulla  with  double  contour  ;  e, 
axis-fibre.  4.  Double  contoured  fibre  from  the  fourth 
ventricle  in  man  ;  the  axis-fibre  (a)  projecting,  and 
visible  within  the  fibre.  5.  Two  isolated  axis-fibres 
from  the  cord,  one  undulated,  the  other  of  unequal  thick- 
ness, with  some  medullary  substance  attached  to  it. — 
Magnified  350  diameters.  {KijUiker.) 


those  above-g^ViT  of  an  inch; 
as  medium  those  from  jj^j'tttj 
to  -jtjVtt  of  ^11  inch;  and  as 
fine  those  less  than  g^Vir  of 
an  inch. 

All  the  nerve-fibres,  when  examined  in  their  recent  state,  and 
by  transmitted  light,  appear  perfectly  transparent,  and  with  simple 
dark  contours.  By  reflected  light  they  appear  opaline,  like  fat,  and, 
in  large  quantities  together,  white;  but  generally  they  do  not  ap- 
pear to  be  composed  of  difl'erent  constituent  parts. 

All  the  coarse  fibres  may,  however,  be  shown  to  consist  of  (Fig. 
273,  and  Fig.  272,  3,4)— 


LARGE   NERVE-FIBRES. 


425 


Fig.  273, 


A,  The  envelop,  or  neurilemma. 

B.  Its  contents,  the  neurine;  consisting  of  the  medulla  and 

the  axis- fibre.  (Fig.  274.) 

A.  The  neurilemma}  is  formed  of  simple  membrane,  and  resem- 
bles elastic  tissue,  but  is  less  soluble  in  alkalies.  Histologically, 
it  very  much  resembles  the  myolemma  of  striated  muscular  fibre, 
and  has  nuclei  upon  its  inner  surface  (p. 
393,  1).  It  has  not  yet  been  demonstrated  in 
the  finest  fibres.  Moreover,  in  case  of  the 
largest  tubes  it  disappears  both  at  its  distal 
extremity,  where  it  is  distributed,  and  also 
in  the  brain  or  spinal  cord,  on  tracing  it  to 
its  origin.  Sometimes,  also,  it  is  wanting 
even  in  the  coarser  fibres  through  a  con- 
siderable extent  of  their  terminal  portions. 

B,  The  contents  of  the  neurilemma  are  a 
homogeneous  substance  during  life,  accord- 
ing to  certain  observers;  and  the  appear- 
ances described  by  Eosenthal  and  Eemak 
are  regarded  by  such  as  due  to  jjost-mortem 
changes.  The  conclusions  of  Kolliker  on 
this  question  are  adopted  here. 

Two  entirely  distinct  substances  are  con- 
tained in  the  nerve-tube;  a  difference  in 
color,  however,  and  density,  being  apparent 
only  after  death.     These  are : — 

1.  The  axis-fibre. 

2.  The  nerve-medulla,  or  pulp. 
1.  The  axis-fibre  {Kolliker),  primitive  band  (Bemak),  or  axis-cylin- 
der {Rosenthal),  is  a  pale,  soft,  cylindrical  or  slightly  flattened,  but 


Nerve-tubes  of  the  common  eel. 
a.  In  water.  The  delicate  line 
on  its  exterior  indicates  the  neu- 
rilemma ;  the  dark  double-edged 
inner  one  is  the  white  substance 
of  Schwann  (medxilla),  slightly 
wrinkled,  b.  The  same  in  ether. 
Several  oil-globules  have  coa- 
lesced in  the  interior,  and  others 
have  accumulated  around  the  ex- 
terior of  the  tube.  The  white  sub- 
stance has  in  part  disappeared. 
(Magnified  300  diameters.) 


Fig.  274. 


An  axis-fibre  (c)  is  seen  prolonged  some  way  beyond  the  broken  edge  of  its  neurilemma  and  the 
white  substance,  or  medulla  (d). 


'  From  )ii~pov,  nerve,  and  xifA.//.a,  a  coat  or  sheatli.  This  term  is  used  to  correspond 
■witli  the  myolemma  of  muscular  tissue ;  while  the  perineurium  and  the  perimysium 
also  correspond. 


426  THE   TISSUES. 

elastic  fibre  (Fig.  274),  in  the  centre  of  the  tube,  and  usually  occu- 
pying about  one-third  of  its  diameter.  It  is  generally  homogeneous, 
though  rarely  faintly  striated  or  finely  granular ;  is  usually  through- 
out of  uniform  size,  solid^  and  resembles  coagulated  albumen.  It 
generally  pursues  a  straight  course,  but  may  be  curved  or  slightly 
undulating  (never  varicose),  with  an  irregular  border.  Chemical 
reagents  also  show  that  it  contains  not  a  trace  of  fat,  but  is  an  albu- 
minous compound ;  though  it  is  not  identical  with  the  fibrine  of 
the  blood,  nor  the  peculiar  element  of  muscular  tissue  (musculine). 
Analogically  with  the  latter  immediate  principle,  it  may  be  termed 
nervine. 

The  axis-fibre  is  found  in  all,  even  the  very  finest,  nerve-tubes; 
and  in  the  latter,  it  only  can  always  be  satisfactorily  demonstrated. 
Its  size  varies  with  that  of  the  nerve-fibre  itself.  Daring  life,  how- 
ever, it  cannot  be  distinguished  from  the  medulla  which  surrounds  it. 

In  the  acoustic  nerve  of  the  sturgeon,  Czermak  has  demonstrated 
the  existence  of  bifurcating  axis-fibres  in  dividing  nerve-fibres. 

2.  The  nerve-medulla,  or  pulp,  is  a  thick,  viscid  fluid,  like  thick 
oil  of  turpentine,  mostly  composed  of  fatty  matter,  and  filling  all 
the  space  between  the  axis-fibre  and  the  inner  surface  of  the  neuri- 
lemma. Consequently  it  occupies  the  two  remaining,  or  external, 
thirds  of  the  diameter  of  the  tube.  In  other  words,  it  is  itself  a 
viscid,  fluid,  hollow  cylinder,  completely  inclosing  and  isolating  the 
solid  axis-fibre,  which  is  placed  within  it.  Hence  its  designation, 
also,  as  the  medullary  sheath.  It  has  also  been  called  the  "white 
substance  of  Schwann." 

The  entirely  different  chemical  reactions  of  the  medulla  and  the 
axis-fibre,  would  seem  to  demonstrate  their  distinct  existence  and 
function ;  though  the  microscope  does  not  distinguish  them  during 
life.  It  is  the  medulla  that  gives  the  dark  border  to  nerve-tubes 
under  the  microscope ;  and  such  are  therefore  termed  medullated  or 
dark-hordered  tubes. 

Although  the  axis-fibre  exists  in  every  nerve-fibre,  many  are  met 
with  which  have  no  medulla — non-medullated  fibres.  These  consist 
of  the  neurilemma,  the  axis-fibre,  and  an  intervening  fluid,  some- 
times identical  in  appearance  with  the  latter,  and  sometimes  similar 
but  more  clear.  These  7^o?i-medullated  fibres  are  also  found  to  occur 
in  continuation  of  the  medullated,  both  when  they  communicate 
with  the  nerve-cells  in  the  encephalon  and  spinal  cord,  and  also  at 
the  peripheral  extremities  of  the  fibres. 


FINE   NERVE-FIBRES. 


427 


The  medulla  is  rapidly  and  invariably  altered  by  the  application 
of  cold  water,  of  most  acids,  &c.  This  change  consists  principally 
in  a  coagulation  of  it,  sometimes  occurring  from  without  inwards, 
and  involving  the  entire  thickness,  or  only  its  outermost  layer.  In 
the  latter  case,  the  nerve-fibres  of  dou- 
ble contour  lines  are  produced;  in 
the  former,  the  contents  become  ap- 
parently wholly  grumous  or  opaque. 
The  neurilemma  gives  the  single  con- 
tour line.  Sometimes,  also,  the  me- 
dulla accumulates  into  larger  masses 
in  places,  and  thus  the  frequently  de- 
scribed varicose  appearance  of  the 
nerve-fibres  is  produced.  (Figs.  275 
and  273.)  In  this  change  the  neuri- 
lemma participates ;  but  in  all  those 
mentioned,  the  axis-fibre  takes  no 
part.  By  pressure,  the  medulla  may 
be  made  to  assume  all  possible  forms. 


2.  The  Fine  Nerve-Fibres. 
The  finest  nerve-fibres  (Fig.  298, 3) 
are  only  o 4^^o  ^f  ^'^  inch  in  diame- 
ter; and  in  these  neither  neurilemma 
nor  medulla  can  be  demonstrated, 
only  the  axis-fibre  being  apparently 
present.    Most  of  them  are,  however. 


T-^Trnn  to  jjtttttt  of  an  inch;  but  these 


TATTOO 


H'cTo  0 


also  have  no  proper  medulla — ^.  e.  are 
non-meduUated.  But  they  contain 
between  the  axis-fibre  and  the  neuri- 
lemma a  substance  sometimes  resem- 
bling the  axis-fibre  of  other  nerves, 
and  sometimes  more  clear.  These 
are  often  called  pale  nerve-fibres,  as 
they  have  only  a  single  contour  line. 
In  the  nervous  centres,  also,  they  frequently  present  a  varicose  ap- 
pearance. (Fig.  275,  ^'.) 

It  has  already  been  seen,  however,  that  a  nerve-fibre  may  be  rae- 
dullated,  coarse,  and  have  a  neurilemma,  in  one  part  of  its  course, 


A.  Diagram  of  a  tubular  fibre  of  a  spinal 
nerve,  a.  Axis-fibre.  h.  Inner  border 
of  medulla,  c,  c.  Its  outer  border,  d,  d. 
Neurilemma. — B.  Tubular  fibres,  e.  In  a 
natural  state,  showing  the  parts  as  in  a. 
f.  The  medulla  and  axis-cylinder  intei'- 
rupted  by  pressure,  while  the  neurilemma 
remains,  g.  The  same,  with  varicosities. 
h.  Various  appearance  of  the  medulla  and 
axis-fibre,  forced  out  of  the  neurilemma  by 
pressure.  1  Broken  end  of  an  axis-fibre 
with  the  medulla  closed  over  if.  fr.  Lateral 
bulging  of  medulla  and  axis-fibre  from 
pressure.  I.  The  same,  more  complete,  g'. 
Varicose  fibres,  of  various  sizes,  from  the 
cerebellum.     (Magnified  320  diameters.) 


428  THE   TISSUES. 

while  it  is  non-mechillated,  pale,  or  even  consists  of  the  axis-fibre 
alone,  in  another  part.  The  division  into  coarse  and  fine  fibres  is 
therefore  more  important,  doubtless,  in  a  histological  than  in  a  phy- 
siological point  of  view.   The  axis-fibre  alone  is  a  constant  structure. 

Pale  or  non-medullated  fibres  naturally  occur  in  the  following 
situations :  1.  Those  of  the  Pacchionian  bodies ;  2.  The  nucleated 
pale  fibres  in  the  terminations  of  the  olfactory  nerves ;  3.  The  per- 
fectly transparent  non-nucleated  fibres  in  the  cornea;  4.  The  pale 
processes  of  the  nerve-cells  in  the  central  organs  and  ganglia.  It 
will  appear  that  all  the  nerve-fibres  of  the  embryo  are  in  the  con- 
dition of  the  pale  fibres  now  under  consideration.  We,  however, 
find  them  in  different  stages  of  development  in  the  adult.  In  the 
olfactory  nerve  they  remain  altogether  in  the  embryonic  stage,  the 
contents  being  much  less  consistent  than  an  axis-fibre.  In  the  Pac- 
chionian bodies  their  contents  in  all  respects  represent  an  axis-fibre; 
and  the  processes  of  the  nerve-cells  often  exactly  resemble  an  axis- 
fibre,  though  they  are  frequently  of  a  softer  consistence,  correspond- 
ing with  the  contents  of  the  nerve-cell. — In  the  invertehrata,  only 
the  pale  nerve-fibres  are  found. 

The  preceding  are  the  only  forms  of  fibres  found  in  the  cerebro- 
spinal nervous  system. 

But  is  there  not  still  another  variety  of  nerve-fibres  (gray  fibres) 
peculiar  to  the  sympathetic  or  ganglionic  nerves? 

So  far  as  any  peculiar  appearance  under  the  microscope  is  con- 
cerned, the  reply  may  be  decidedly  in  the  negative;  though  Bidder 
and  Volkmann  maintained  that  these  fibres  are  smaller  than  those 
in  the  cerebro-spinal  nerves,  and  also  in  other  respects  different. 

The  fact  is,  the  cerebro  spinal  nerves  contain  dark-bordered  tubes 
of  all  sizes,  from  the  finest  to  the  largest;  those  derived  from  the 
sensitive  roots  of  the  spinal  nerves  being  generally  finer  than  those 
from  the  motor  roots.  But  the  branches  of  the  sympathetic  also 
contain  the  same  varieties  of  nerve-fibres,  the  only  perceptible  dif- 
ference being  that  the  proportion  of  the  finer  tubes,  T^^trtr  to  g^'g^  of 
an  inch  in  diameter,  is  greater  in  the  sijmjMlhetic  nerves.  Some  of 
these  fine  fibres  arc  also  known  to  originate  in  the  ganglia  of  the 
sympathetic,  but  in  a  manner  similar  to  the  origin  of  the  fine  fibres 
of  the  cerebro-spinal  nerves  in  the  cord  and  the  encephalon.  We 
also  find  fine  fibres,  precisely  like  the  so-called  sympathetic  fibres, 
constituting  the  distal  termination  of  the  coarsest  nerve-fibres;  and 
that  all  the  coarsest  double-bordered  nerve-fibres  are,  at  a  particular 


GELATINOUS   NERVE-FIBRES. 


429 


period  of  their  development,  precisely  in  the  condition  of  these 
fibres  of  the  sympathetic.  Finally,  it  is  even  true  that  the  same 
fibre  in  the  adult  is  often  seen  to  assume  all  possible  varieties  of  size 
in  different  portions  of  its  course. 

There  are,  therefore,  no  nerve-fibres  peculiar  to  the  sympathetic 
nerves;  there  being  only  the  fine  and  the  large  fibres  already  de- 
scribed as  existing  in  the  cerebro-spinal  system. 

How,  then,  may  we  dispose  of  still  other  fibres  found  more  espe- 
cially in  the  peripheral  branches  of  the  ganglionic  (sympathetic) 
nerves — the  "gelatinous  fibres,"  or  "fibres  of  Eemak?"      These, 


when  isolated,  present  the  aspect  of  flat,  pale  fibres,  gAtr  to 


4S^0 


of 


an  inch  wide,  and  377^0  o  of  ^"^  moh  thick,  of  an  indistinctly  striated, 
granular,  or  more  homogeneous  substance.     In  these,  acetic  acid 
shows  elongated  or  fusiform  nuclei,  averaging  about  34^00  of  an 
inch  in  length,  and  4gVo  of  ^"^  vaoh.  in  width.    (Fig. 
276.)     They  are  found  in  great  abundance  in  the 
nerves  of  the  impregnated  uterus  (RemaJc),  some- 
times amounting  to  from  three  to  ten  times  the  num- 
ber of  the  dark-bordered  true  nerve-fibres. 

With  Valentin,  Kolliker,  Bidder,  and  Yolkmann, 
we  regard  the  fibres  just  described  merely  as  a  form 
of  elastic  tissue,  or  nuclear  fibres.  For,  1st,  they  ap- 
pear to  arise  from  the  wall  of  the  nerve-cells  of  the 
sympathetic  ganglia;  2dly,  they  also  exist  in  the 
finest  twigs  of  the  spinal  nerves,  but,  being  absent 
in  the  trunks,  must  be  otherwise  than  nerve-fibres ; 
Sdly,  their  quantity  always  diminishes  towards  the 
finest  ramifications,  which  could  not  be  the  case 
were  they  true  nerve-fibres.  This  question  cannot, 
however,  be  settled  in  young  animals;  though  in 
them  a  nucleated  fibre  is  not  to  be  regarded  as  a 
nerve-fibre,  unless  it  can  be  traced  into  a  dark -bor- 
dered nerve-fibre,  or  to  a  process  of  a  nerve-cell. 

Finally,  the  fibres  of  Eemak  occur  also  in  the  ganglia  on  the  main 
sympathetic  trunk ;  but  they  do  not  extend  much  beyond  them, 
and  therefore  few  are  contained  in  the  trunk  of  the  nerve  itself. 


Gelatinous  fibres 
(fibres  of  Eemak) 
froiu  the  solar  plex- 
us;  treated  with  a- 
cetie  acid  to  exhibit 
their  cell-nuclei. — 
(Magnified  320  dia- 
meters.) 


Distribution  of  the  Nerve-Fibres. 
The  nerve-fibres  constitute  the  principal  part  of  all  the  nerves, 
both  cerebro-spinal  and  ganglionic.     They  also  constitute  most  of 


430  THE   TISSUES, 

the  white  (fibrous)  portion  of  the  encephalon  and  the  spinal  cord; 
while  thej  also  sometimes  form  even  one-half  of  the  gray  substance 
of  these  two  organs  and  of  the  ganglia. 

It  has  already  been  shown  that  there  are  at  least  eight  or  nine 
times  as  many  coarse  as  fine  fibres  in  muscles  (p.  415);  while  the 
fine  fibres  greatly  predominate  in  the  ganglionic  nerves. 

Chemical  Composition  of  the  Nerve- Fibres. 

It  appears  that  the  neurilemma  and  the  axis-fibre  very  much 
resemble  elastic  tissue,  and  are  albuminous  compounds ;  while  the 
medulla  is  rather  a  fatty  compound.  It  is  not,  however,  to  be  sup- 
posed that  either  of  these  three  has  a  chemical  composition  precisely 
identical  with  that  of  any  other  tissue  whatever.  The  nerve-tissue 
has  vital  properties  which  are  sui  generis,  and  doubtless  its  chemical 
composition  is  peculiar.  When  the  immediate  principle  peculiar  to 
this  tissue  is  identified,  it  may,  from  analogy,  be  called  nervine  (p. 
426).  A  quantitative  analysis  of  the  nerve-fibres  occurring  to  form 
masses,  will  be  given  in  connection  with  the  fibrous  substance  of 
the  brain. 

The  vessels  of  the  nerve-fibres  will  also  be  described  further  on. 

Functions  of  the  Nerve-Fibres. 

It  is  very  certain  that  the  nerve-fibres,  in  all  cases,  merely  minister 
to  the  central  parts  of  the  nervous  system ;  being  merely^  the  media 
by  which  impressions  are  transmitted  to  and  from  the  latter. 

From  the  statement  of  Volkmann  (p.  415),  we  must  infer  that  many 
at  least  of  the  coarser  fibres,  if  not  all,  are  employed  in  traasmitting 
impulses  to  the  muscles,  and  are  therefore  motor  nerve-fibres.  On 
the  other  hand,  the  fine  fibres  are  not  motor,  since  in  muscles  they 
are  sent  to  the  vessels  especially  (p.  416).  They  also  abound  in  the 
ganglionic  nerves.  The  inference,  therefore,  is,  that  the  fine  fibres 
must  include  both  tlie  sensory  and  the  ganglionic,  and  both  of 
which  are  afferent — i.  e.  they  conduct  impressions  to  the  centres  and 
ganglia;  while  the  coarse  fibres  arc  efferent.  Still,  we  must  not 
assert  that  a  motor  fibre  is  coarser  throughout  its  entire  extent, 
since  they  sometimes  become  very  fine  at  their  distal  extremity. 

In  regard  to  the  office  of  each  of  the  three  component  parts  of 

'  In  the  performance  of  this  function,  however,  "  the  whole  extent  of  the  fibre 
between  the  point  stimulated  and  its  peripheral  and  central  connection  is  the  seat 
of  change  "  {Todd  and  Bowman,  p.  235.) 


FUNCTIONS   OF   NEBVE-FIBRES. 


431 


the  ncrvc-fibres,  we  would  submit  that  the  neurilemma  is  originally 
for  the  development  of  the  contained  parts ;  the  medulla  protects 
and  isolates  the  axis-fibre ;  while  the  latter  is  endowed  with  the  pe- 
culiar vital  property  of  the  fibre,  whether  it  be  efferent  or  afi'erent. 
Thus  the  motor  fibres,  being  most  exposed  to  undergo  pressure 
among  the  muscular  fibres  while  contracting,  need  a  thicker  me- 
dulla, and  are  therefore  coarser.  The  fibres  of  the  ganglionic  nerves 
are  at  the  other  extreme  in  this  respect ;  since  they  are  mostly  dis- 
tributed to  internal  parts  and  organs,  and  at  the  same  time  follow 
vessels  more  especially.  It  also  occurs,  that  a  thick  medulla  at  the 
distal  extremity  of  a  sensory  fibre  would  of  course  interfere  with  a 
prompt  impressibility  of  the  axis-fibre,  though  it  might  become 
medullated  while  lying  in  the  nerve-trunks.  Evidently,  also,  the 
protection  of  a  medulla  is  not  required  after  the  fibres  enter  the 
substance  of  the  encephalon  and  spinal  cord;  and  here  the  fibres 
are  non-medullated. 

For  the  present,  therefore,  we  are  not  perhaps  allowed  to  assume 
more  than  that  a  fibre  which  is  thickly  medullated  throughout  its 
entire  course,  is  very  probably  a  motor  fibre.  But  some  of  the  finer 
fibres  may  also  be  motor.  The  finest  fibres  are  not  peculiar  to  the 
ganglionic  nerves;  and  if  they  actually  manifest  a  peculiar  function 
(i.  e.  as  the  great  sympathetic)^  that  function  is  probably  manifested 
by  the  spinal  nerves  also,  in  proportion  to  the  fine  fibres  they 
contain. 

Development  of  the  Nerve-Fibres. 
The  peripheral  portions  of  the  nerve-fibres  are  developed  inde- 
pendently of  the  central  portions;  but  in  such  a  way  that  the  lat- 


1.  Tivo  nerve-fibres  from  the  ischiatic  nerve  of  a  sixteen  weeks"  embryo.  2.  Nerve-tubes  from  a 
newly  littered  rabbit,  a.  Neurilemma.  6.  Nucleus,  c.  Medullary  sheath.  3.  Nerve-fibre  from  the  tail 
of  the  tadpole  (a,  6,  c),  as  before;  at  d,  the  fibre  retains  its  embryonic  character  ;  the  dark  bordered 
fibre  shows  a  division.   (Kolliker.) 


432 


THE   TISSUES. 


Fig.  278. 


ter  precede  the  former.  The  development  of  the  peripheral  extre- 
mities of  the  nerve-fibres  is  also  peculiar,  and  requires  a  distinct 
consideration. 

1.  The  nerve-fibres  in  the  nerve-trunks,  except  their  peripheral 
terminations,  are  developed  in  their  positions,  from  primordial, 
fusiform,  nucleated  cells,  conjoined  into  pale,  flattened,  nucleated 
tubules,  T 3^17  0  to  4u'oo  of  an  inch  broad.  (Fig.  277.)  In  this  state 
they  are  gray,  or  dull  white ;  but  in  the  embryo  at  the  4th  to  the 

5th  month,  they  assume  a 
white  color,  and  the  me- 
dulla continues  to  be  more 
and  more  developed  in 
them,  and  thus  they  be- 
come dark-bordered  fibres. 
Thus  the  axis-fibre  ap- 
pears to  be  developed 
from  the  central  portion 
of  the  contents  of  the  ori- 
ginal tubule,  while  the 
external  portions  undergo 
a  sort  of  fatty  metamor- 
phosis into  the  medulla. 

2.  The  development  of 
the  peripheral  terminations 
of  the  nerve-fibres,  has 
been  investigated  satis- 
factorily only  in  the  tail 
of  the  tadpole.  The  pale 
nucleated  tubules  describ- 
ed under  the  preceding 
head,  here  and  there  anas- 
tomose, and  terminate  in 
free   fibrils  of  the   finest 


kind 


inch    in 


to 


TETT^OTT 


of 


NcrvpB  from  the  tail  of  a  tadpole.  1.  Emliryoiiic  nerve- 
fibres  in  which  more  than  one  <lark-})or(lprcd  tube  has  been 
developed.  2.  Similar  flbroH  containing  but  one  tube,  which 
in  one  fibre  ceases  at  (h).  3.  Embryonic  pale  fibres :  4,  fusi- 
form cells  connected  together,  and  with  a  complete  nerve- 
fibre.— .Magnified  3.00  diameters.     (KolWcer.) 


an  incu  m  diameter. — 
These  are  evidently  form- 
ed from  the  coalescence  of 
fusiform  or  stellate  cells ; 
and  continue  to  be  pushed 
further  by  offsets  towards 


DEVELOPMENT   OF   NERVE-FIBRES.  433 

the  periphery,  and  finally  form  a  very  fine  terminal  plexus,  with 
anastomoses  and  free  ends.  (Fig.  278.)  Next,  the  fibres  gradually 
enlarge  to  from  two  to  four  times  their  original  diameter,  and  dark 
bordered  fine  fibres  are  gradually  developed  in  them  in  the  peri- 
pheral direction.  Sometimes  two  to  four  dark-bordered  tubules 
are  developed  within  the  same  embryonic  fibre,  in  the  tadpole;  a 
fact  not  yet  established  in  regard  to  the  higher  animals. 

3.  The  development  of  the  nerve-fibres  in  the  central  organs  has 
not  been  thoroughly  investigated.  Tubules  begin  to  form,  how- 
ever, in  the  white  substance  of  the  foetal  brain  at  the  end  of  the 
2d  month,  by  the  coalescence  of  cells.  In  the  4th  month,  nuclei 
are  still  occasionally  to  be  seen  in  the  now  wider  fibres,  though  the 
latter  do  not  become  dark-colored  before  the  middle  period  of  foetal 
life;  and  in  the  white  portion  of  the  cord  sooner  than  in  that  of  the 
brain. 

The  fibres  in  the  ganglia  are  developed  subsequently  to  those  of 
the  nerve-trunks,  and  apparently  in  the  manner  just  described. 

The  growth  of  the  nerve-fibres  is  apparently  secured,  after  the 
4th  month  of  embryonic  life,  solely  by  the  enlargement  of  the 
already  existing  elements.  No  new  fibres  are  found  after  this  pe- 
riod. According  to  Harting,  the  size  of  the  fibres  in  the  median 
nerve  in  the  human  foetus  at  4  months,  the  new-born  child,  and  the 
adult,  is  as  3.4,  10.4,  and  166. 

•  When  nerve-fibres  are  cut  across,  they  readily  unite ;  and  por- 
tions, 8  to  12  lines  long,  may  be  entirely  regenerated,  when  removed 
from  the  peripheral  nerves.  Incised  wounds  of  the  spinal  cord 
unite  also.     {Brown  Stquard) 

Pathological  States  and  New  Formations  of  the  Nerve-Fibres. 

1.  The  nerve-fibres  are  readily  destroyed  by  extravasation  of 
blood,  tumors,  softening,  fibroid  growths,  &c. ;  in  which  case  the 
medulla  breaks  up  into  larger  or  smaller  masses,  while  the  axis- 
fibre  disappears.  Continued  pressure  sometimes  leads  to  a  com- 
plete interruption  of  continuity  of  the  fibres  at  the  point  com- 
pressed. 

2.  In  atrophied  nerves  the  fibres  are  thinner,  easily  broken  up, 
and  sometimes  the  medulla  is  converted  into  minute  fatty  mole- 
cules. 

3.  It  is  not  known  that  hypertrophy  of  the  nerve-fibres  ever 
occurs. 

4.  In  case  a  divided  nerve  does  not  unite  (as  necessarily  after 
amputation),  the  fibres  usually  become  yellowish,  soft,  lacerable,  and 

28 


434 


THE   TISSUES, 


uo  longer  present  any  trace  of  a  double  contour,  the  medulla  being 
coagulated. 

5.  What  is  called  neuroma  is  decided  by  Wedl  to  be,  sometimes 
at  least,  a  cancerous  deposit  in  the  continuity  of  a  nerve. 

6.  A  neiv  formation  of  fine  nerve-fibres  was  noticed  by  Virchow 
in  pleuritic  and  peritoneal  adhesions. 

II.  Cellular  {vesicular)  Nerve-Tissue,  or  Nerve-Cells. 

The  nerve-cells  (nerve-corpuscles,  Valentin)  vary  extremely  in 
their  size ;  occurring,  like  the  nerve-fibres,  as  large,  small,  and  in- 
termediate. The  extremes  are  gg'g^,  and  ^^^  of  an  inch.  The 
nuclei  are  from  goV^  to  g^Vw  of  an  inch,  and  the  nucleoli  54^x7^  to 
4^Vo  of  an  inch  in  diameter. 

Many  varieties  oi  form,  are  also  presented  by  the  nerve-cells. 
(Figs.  279  and  280).    The  spherical  form  (apolar  cells)  occurs  more 

Fig.  279. 


C  D  E 

Varions  forms  of  nerve-cells,  a,  b.  Large  stellate  cells  with  tholr  prolongations;  from  the  anterior 
horn  of  the  gray  matter  of  tlie  spinal  cord.  c.  Nerve-cell  with  its  connected  fibre  ;  from  the  anasto- 
mosis of  the  facial  and  auditory  nerves  at  the  meatus  auditorius  internus  of  the  ox.  a.  Cell-wall. 
b.  CcU-contonts.  c.  PiginiMit.  d.  Nucleus,  e.  Prolongation  forming  tlie  neurilemma,/,  of  the  fibre. 
D  Nerve-cell  from  the  substantia  forruginea  of  man.  e.  Smaller  cell  from  the  spinal  cord.  (Mag- 
nified 300  diameters.) 

abundantly  in  the  ganglia ;  but  the  original  form  of  most  nerve- 
cells  is  modified  by  prolongations — poles,  or  pale  processes.  Of 
these  there  may  be  from  1  to  5,  or  even  8 ;  hence  the  cells  are 
termed  uni-,  bi-,  tri-,  or  multi-polar.  These  processes  are  also  fre- 
quently branched.  (Fig.  280.)  There  are,  however,  no  cells  with 
branched  processes  in  the  ganglia;  but  only  those  having  1  to  4 
pale  processes,  and  which  are  continuous  with  dark-bordered  nerve- 
fibres. 


NERVE-CELLS.  436 

The  cell-memljrane  may  be  demonstrated  easily  in  the  cells  of  the 
ganglia,  but  with  great  difBculty  in  those  of  the  central  organs,  and 
not  at  all  in  the  smallest  cells  of  the  latter.  No  membrane  can  be 
detected  iu  the  processes  of  the  central  cells  generally. 

The  contents  of  the  nerve-cells  are  a  soft,  tenacious,  elastic,  sub- 
stance, consisting  of  two  elements,  besides  the  nucleus ;  (1),  a  clear, 
light-j^ellowish,  or  colorless,  homogeneous  substance,  an  albumin- 
ous compound  \idvj  much  resembling  the  axis-fibres,  and  on  which 
the  physical  properties  of  the  contents  depend ;  and  (2),  minute 
granules  of  different  kinds  suspended  in  the  former.  These  are 
sometimes  larger  and  yellowish,  brown,  or  blackish ;  in  which  case 
the  cells  are  colored  (as  forming  the  gray  matter  of  the  nervous 
centres);  while  in  the  colorless  nerve-cells  they  are  minute  and 
pale,  -uniform,  and  roundish  in  form.  They  consist,  in  great  part, 
of  fat. 

The  nucleus  lies  in  the  midst  of  the  contents  just  mentioned : 
usually  as  a  very  clear  spherical  vesicle  with  distinct  walls,  trans- 
parent contents,  and  one,  and  rarely  several,  opaque  nucleoli,  occa- 
sionally exhibiting  a  cavity. 

Distribution  of  the  Nerve-  Cells. 
The  nerve-cells  occur  in  great  numbers  in  the  gray  substance  of 
the  encephalon  and  spinal  cord,  in  the  ganglia,  and  occasionally 
also  in  the  trunks  and  peripheral  expansions  of  the  nerves ;  as  in 
the  retina,  cochlear  nerve,  &c. 

Chemical  Composition  and  Physical  Properties  of  the  Nerve-Cells. 

The  chemical  composition  of  the  gray  portion  of  the  brain 
(made  up,  in  great  part,  of  the  cells  in  question),  will  be  given  fur- 
ther on  in  this  chapter. 

If  isolated  nerve-cells  are  compressed,  they  become  much  flat- 
tened, but  resume  their  original  form  after  the  pressure  is  removed. 
Their  processes  also  are  very  elastic. 

An  abundance  of  blood  is  distributed  to  the  nerve-cells;  The 
vessels  will  be  described  in  the  second  part  of  this  chapter. 

Functions  of  the  Nerve- Cells. 
Since  the  nerve-cells  constitute  the  principal  element  in  the  gray 
matter  of  the  centres,  and  of  the  ganglia,  and  this  presides  over  the 
higher  functions  of  the  nervous  system,  while  its  other  portions  are 


436 


THE   TISSUES. 


merely  a  conducting  apparatus  (p.  430) ;  it  must  be  inferred  that 
the  cells  are  the  source  of  motor  impulses  on  the  one  hand,  and 
the  recipients  of  sensory  impressions  on  the  other. 

It  has  been  seen  that  the  largest  nerve-fibres  are  certainly  mostly 
motor,  and  the  finest  sensory  and  ganglionic.  We  also  find  the 
largest  nerve-cells  in  situations  whence  motor  effects  proceed :  as  in 
the  anterior  horns  of  the  spinal  cord,  among  the  fibres  of  the  ante- 
rior roots  of  the  spinal  nerves;  in  the  medulla  oblongata,  at  the 
points  of  origin  of  the  motor  cerebral  nerves;  and  in  the  cortical 
substance  of  the  cerebellum,  pons  Varolii,  and  crura  cerebri.  On 
the  other  hand,  the  smallest  cells  are  found  in  the  sensitive  and 
sympathetic  regions — as  the  posterior  horns  of  the  spinal  cord,  the 
corpora  restiformia,  and  quadrigemina;  and  in  the  sympathetic 
ganglia.  Still,  there  is  no  constant  relation  between  the  size  of  the 
cells  and  their  function,  whether  motor,  sensory,  or  sympathetic; 
since  in  the  optic  thalami  and  in  the  ganglia  of  the  cerebro-spinal 
nerves,  and  even  of  the  sympathetic,  both  sorts  of  fibres  arise,  from 
large  cells  in  one  place,  and  from  small  ones  in  another.  There  are, 
however,  more  small  cells  in  the  sympathetic  ganglia. 

Bat  it  must  be  remembered  that  many  of  the  cells  in  the  cere- 
brum and  the  cord  are  probably  neither  motor,  sympathetic,  nor 
sensory.   Such  are  those  which  are  not  in  direct  connection,  through 

Fig.  280. 


n.  A  large  nerve-cell  with  diverging  and  branching  processes,  some  of  which  (6)  are  seen  to  pass 
off  into  extremely  minute  filaments.  These  bear  a  very  close  resemblauco  to  the  axis-cylinder 
of  a  tubular  flbro.    «.  Small  nerve-cells.    /.  Small  norve-fibros,  some  being  varicose. 

their  processes,  with  the  nerve-fibres.  Of  these  there  are  two  kinds: 
\st,  apolar  cells,  existing  in  the  sympathetic  ganglia,  and  in  some 
situations  in  the  brain  (Fig.  289);  2dbj,  multipolar  cells  (Fig.  280), 


.STRUCTUKE    OF   TUE   NERVOUS   SYSTEM.  437 

which  are  not  prolonged  into  nerve-fibres..  It  is  not  easy  to  specify 
the  function  of  the  former;  but  since  the  processes  of  the  latter 
apparently  fulfil  the  functions  of  nerves,  it  is  probable  that  they 
bring  different  regions  of  the  central  organs  into  mutual  connection. 
Cells  of  this  kind  exist  in  the  spinal  cord  and  the  brain  every- 
where, in  large  amount,  but  not  in  the  ganglia. 

The  cells  in  the  gray  matter  of  the  brain,  which  is  regarded  as 
the  seat  of  the  mental  manifestations,  exhibit  no  peculiarities  by 
our  present  means  of  research. 

While,  therefore,  we  may  regard  cells  connected  with  uerve-fibres 
as  being  either  motor  or  afferent,  the  functions  of  the  apolar,  and 
the  multipolar  not  thus  connected,  must  be  established  by  future 
investigations. 

Development  of  the  Nerve-  Cells. 

The  nerve-cells  are  merely  transformed  primordial  cells;  some 
simply  enlarging,  while  others  throw  out  a  varying  number  of  pro- 
cesses, and  some  of  them  are  connected  with  nerve-fibres. 

Many  nerve-cells  also  appear  at  a  subsequent  period  to  increase 
by  division,  from  the  fact  that  two  nuclei  sometimes  occur  in  the 
nerve-cells  of  young  animals. 

Yalentin  thinks  he  observed  regeneration  of  nerve-cells  in  the 
superior  cervical  ganglia  of  the  rabbit.  Gluge  also  maintains  that 
the  gray  matter  of  the  brain  is  reproduced  after  being  removed. 

Pathological  States  and  New  Formations  of  the  Nerve-Cells. 

The  deposit  of  pigment-granules  becomes  excessive  in  the  cells 
of  the  brain  in  old  persons.  Fatty  deposition  also  occurs  in  them — 
a  fatty  degeneration. 

The  ganglia  become  atrophied  in  old  persons ;  in  which  case  the 
ganglion -cells  are  less  numerous,  and  contain  more  pigment.  Atro- 
phy of  the  abdominal  ganglia  also  occurs  as  a  sequel  of  typhus. 
{Racihorski?) 

A  new  formation  of  gray  nerve-cells  sometimes  occurs  on  the 
walls  of  the  cerebral  ventricles.  ( Virchoio.) 

SECTION   II. 
STRUCTURE    OF   THE   NERVOUS   SYSTEM. 

The  nervous  system  consists  of — 

I.  The  nerves  proper,  and  their  ganglia. 
II.  The  nervous  centres. 


438  THE   TISSUES. 

I.  Steucture  of  the  Nerves. 
The  nerves  contain  tlie  following  histological  elements: — 

1.  Nerve-fibres. 

2.  Areolar  tissue, 

3.  Bloodvessels. 

1.  The  nerve-fibres  have  been  sufficiently  described  (pp.  423-9). 

2.  The  areolar  tissue  is  insinuated  between  the  individual  fibres 
in  the  nerve-trunks,  and  also  invests  the  whole  nerve  externally, 

and  is  therefore  termed   the  ^^ermew- 
^'S-  281.  rium.^    Fig.  281  shows  a  section  of  the 

r    a  ischiatic  nerve  of  the  calf,  and  the  areo- 

lar tissue  between  its  component  nerve- 
fibres  ;  the  latter  being  first  collected 
into  the  primary  fasciculi,  and  these 
into  the  secondary,  as  has  been  shown 
in  respect  to  the  fibres  of  muscle  and 

Transverse  section  of  the  ischiatic      of  tcudon.     The  finCSt  SubdivisioUS  (iu- 

nerve  of  the  calf,  a  External  perineu-    Vernal  perineurium)  of  the  perineurium, 

rium.     6,  c.   Internal   perineurium   in-  _  ^  '  ^    _ 

vesting  the  separate  fasciculi  of  nerve-    lying  bctwecu  the  fibrcs  are  iu  the  form 

fibres  of  which  the  nerve-trunk  is  made      ^^  ^  homOgenCOUS  mcmbranC,  with  UU- 
up. — Magnified  1.5  diameters.  (Kijlliker.)  ° 

clei  4^'g5  of  an  inch  in  diameter,  and 
which  may  be  regarded  as  embryonic  collagenous  tissue  (p.  276). 
The  elastic  fibres  are  not  seldom  entwined  around  whole  fasciculi. 

8.  The  bloodvessels  of  the  nerves  are  not  very  numerous.  They 
extend  principally  in  a  longitudinal  direction,  and  form  a  loose 
plexus  of  minute  capillaries  of  5,-,'^^  to  g^'oo  ^f  an  inch,  with  elon- 
o-ated  interstices.  This  invests  the  fasciculi,  and  penetrates  them, 
but  never  surrounds  individual  nerve-fibres. 

The  nerves,  in  respect  to  their  origin,  are  of  three  kinds,  and 
will  be  described  in  the  following  order: — 

1.  The  spinal  nerves. 

2.  The  ganglionic  nerves. 
8.  The  encephalic  nerves. 

'  From  Trepj,  ai-oiind,  and  vei^cov,  a  nerve. 


SPINAL   NERVES. 


439 


1.  The  Spinal  Nerves. 
Tlie  thirty-one  pairs  of  nerves  connected  witli  the  spinal  cord 
rise  from  two  roots,  anterior  and  posterior,  or  motor  and  sensory. 
(Fig.  282.)     Sometimes,  how- 
ever, the  first  nerve  has  only  Fig-  282. 
an  anterior  root,  and  the  last 
a  posterior  only. 

1,  The  roots  of  the  spinal 
nerves  are  inclosed  in  a  de- 
licate perineurium  derived 
from  the  pm  mater ^  gTjV?y  o^ 
an  inch  thick,  and  sending  in- 
ternal septa  among  the  indi- 
vidual nerve-fibres,  which  are 
coarse  in  the  motor  root.  An- 
astomoses between  the  roots 
frequently  occur,  and  far  most 
so  between  the  posterior  roots. 

The  two  roots  converging, 
separately  perforate  the  arach- 
noid and  dura  mater,  and  re- 
ceive a  firmer  investment 
from  the  latter;  then  proceed- 
ing further,  the  posterior  root 
forms  its  ganglion ;  after  which 
the  two  roots  unite  to  form 
the  common  spinal  nerve- 
trunk. 

2.  The  ganglion  on  the  pos- 
terior root  is  formed  as  fol- 
lows: Nerve-cells  {ganglion-cells)  are  developed  among,  but  princi- 
pally externally  to,  the  nerve-fibres,  each  giving  off  one,  two,  or 
several  nerve-fibres  {ganglion-fihres),  which  proceed  in  company  with 
the  original  sensitive  fibres  of  the  posterior  root,  and  merely  pass 
among  the  ganglion-cells,  and  reunite  after  traversing  the  ganglion. 
The  root,  however,  becomes  somewhat  increased  in  size  from  the 
addition  of  the  ganglion-fibres.  (Fig.  283.) 

The  ganglion-cells  have  a  distinct  membrane,  are  mostly  rounded, 
elongated,  or  pyriform,  and  a  little  flattened,  averaging  g^^  to  ^^^ 


The  two  roots  of  a  dorsal  spinal  nerre,  and  its 
union  with  the  sympathetic,  c,  c.  Anterior  Assure  of 
the  spinal  cord.  a.  Anterior  root.  p.  Posterior,  with 
itsganglion.  a'.  Anterior 6ranc?j.  p'.  Posterior &rawc/i. 
s.  Sympathetic,  e.  Its  double  junction  with  the  an- 
terior branch  of  the  spinal  nerve  by  a  white  and  a 
gray  filament. 


440 


THE   TISSUES. 


Fig.  283. 


B.M. 


of  an  incli.     Their  con- 
tents are  finely  granular 
througliout,  and  frequent- 
ly exhibit  near  the  du- 
cleus  an  accumulation  of 
yellow   or  yellowish- 
brown    larger    pigment- 
granules,  which  increases 
in  old  age.      The  nuclei 
average  oo'oTTi^.nd  the  nu- 
cleoli   gTxVo    of  ^^   inch. 
The  cells  are  more  abun- 
dant on  the  surface  of  the 
ganglion,  between  the  pe- 
rineurium and  the  origi- 
nal sensitive  fibres;   but 
they  also  occupy  the  in- 
terstices   between    these 
fibres.      They  are   appa- 
rently retained   in   their 
place  by  ofi'sets  from  the 
perineurium,   and   which 
form  a  special  nucleated 
capsule     around     them, 
called  their  external  sheath. 
(Fig.  284.)      "Fibres   of 
Remak"  are  also    found 
among   the    elements    of 
the  ganglia  (p.  429). 

By   far    the    greatest 

number  of  the  ganglwn- 

cells  give   off  pale   pro- 

in  diameter.     These  are  continued 


A  lumbar  ganglion  of  a  young  dog,  treated  with  soda. 
S.  Sensitive  root.  M.  Motor  root.  R.  a.  Anterior  branch 
of  the  spinal  nerve.  R.  p.  Posterior  branch.  In  both,  thoir 
derivation  from  both  roots  is  manifest.  O.  Ganglion,  with 
the  cells  and  ganglion-flbres,  g,  which  assist  in  strengthening 
the  sensitive  roots,  traversing  the  ganglion.  (Magnified  4.'5 
diameters.) 

cesses  g^'^^  to  ^^Vtt  of  ^"^  i^^^h 

into  dark-bordered  and  double-contoured  nerve-fibres  (the  ganglion 

fibres).     (Fig.  285,  A.) 

Possibly  apolar  ganglion-cells  also  exist,  but  this  is  not  certain ; 
and  if  there  be  any  bipolar  cells,  both  their  ganglion -fibres  are  be 


'  Apolar  cells  are  frequently  met  with  in  the  ganglia  aberrantia  of  Hyrtl ;  i.  e. 
the  inconstant  larger  or  smaller  collections  of  cells  on  the  posterior  roots  of  some 
of  the  larger  spinal  nerves. 


SPINAL   NERVES. 


441 


lieved  to  extend  in  the  peri-  Fig-  284. 

pheral  direction. 

3.  The  ganglion-fibres  thus 
arising,  which  frequently  arch 
round,  or  embrace  the  cells 
with  several  circular  turns,  are 
at  first  fine,  or  g^Vij  to  ^^J^^  of 
an  inch ;  but  increase  up  to 
T^TTTT,  ^ttVit,  ^ud  cveu  to  s^Vtt 
of  an  inch,  while  still  with- 
in the  ganglion,  thus  becom- 
ing thick  fibres.  The  special 
sheaths  of  the  pale  processes 
are,  however,  continued  over 
the  fibre  only  till  it  leaves  the 
ganglion,  when  the  common 
perineurium  takes  their  place. 

It  is  clear  that  the  subdivisions  of  the  trunks  of  the  spinal  nerves 
formed  as  already  explained,  will  contain  motor,  sensory,  and  gan- 

Fig.  285. 


From  the  Gasserian  ganglion  of  an  adult,  a,  a. 
Ganglion  cells  with  their  nucleus,  nucleated  cap- 
sule, and  pigment.  t.  Tubular  fibres  running 
among  the  cells  in  contact  with  their  capsule,  g. 
Gelatinous  (Remak's)  fibres  also  in  contact  with 
the  ganglion-cells.     (Magnified  320  diameters.) 


Connection  between  nerve-fibres  and  nerve-cells  ;  from  the  roots  of  a  spinal  nerve  of  the  ray.  a. 
A  nerve-cell  escaped  by  pressure  from  the  capsule  formed  around  it,  by  the  dilated  sheath  of  the 
nerve-tubule  ;  it  shows  also  the  gradual  disappearance  of  the  outer  portion  of  the  substance  of  the 
nerves  as  it  comes  into  relation  with  the  cells,  b.  A  nerve-cell  inclosed  within  a  dilated  portion  of 
the  neurilemma  of  a  nerve ;  part  of  the  granular  material  of  the  cell  is  continuous  with  the  axis- 
fibre  of  the  nerve  in  the  course  of  which  it  is  inserted. 

glionic  nerve-fibres.  The  coarse  fibres  are  finally  sent  to  the  mus- 
cles, and  the  finer  are  given  off  in  the  cutaneous  nerves,  and  those 
of  other  sensitive  parts.  The  ultimate  distribution  of  the  ganglionic 
fibres  has  not  been  anatomically  settled.  They  are,  however,  pro- 
bably mostly  given  off  in  the  vascular  nerves  of  the  extremities, 
glands,  and  skin. 

The  proportion  of  the  coarse  to  the  fine  fibres  in  the  main  trunks 
of  the  spinal  nerves,  is  as  10  to  11;  while  in  the  muscular  nerves  it 


442 


THE   TISSUES. 


is  as  10  to  from  1  to  3.3,  {Bidder  and  Volkmann.)  The  nerves  of  bone 
contain  in  their  trunks  ^  of  coarse,  and  f  of  fine  fibres;  while 
those  of  the  articulations,  tendons,  and  membranes,  exhibit  a  great 
preponderance  of  fine  fibres.  {Kolliker) 

4.  The  manner  in  which  the  motor  nerve-fibres  terminate  (by 
divisions,  &c.),  has  already  been  described  (p.  416).  The  termina- 
tions of  the  sensory  fibres  in  loops,  divisions,  and  free  terminations, 
will  be  described  in  the  chapter  on  the  skin.    (Chap.  XI.) 

A  peculiar  form  of  termination  of  the  spinal  nerves,  is  however 
to  be  noticed  here ;  viz.,  that  in  the  Pacinian  bodies}     These  organs 

Fig.  286. 


A.  Nerve  from  tlicfingpr,  natural  size;  showing  the  Pacinian  corpuscles,  b.  Ditto,  magnified  2 
liiamcters  ;  showing  their  (lilTerent  size  and  shape,  c.  Single  corpuscle,  highly  magnified,  showing 
a,  its  peduncle,  6,  its  contained  nerve-fihre  ;  e,  outer  layers,  and  <?,  inner  layers  of  the  capsule  ;  e, 
uerve-fibre  become  pale  in  its  passage  through  the  interior  of  the  corpuscle  ;  /,  its  subdivision  and 
termination. 


are  of  an  elliptical  or  pyriform  shape,  of  a  whitish  transparent  color, 
with  white  streaks  internally,  and  are  from  j'^  to  ^  of  an  inch  in 
diameter.  They  are  constantly  found  on  the  cutaneous  nerves  of 
the  palm  of  the  hand,  and  the  sole  of  the  foot,  in  the  subcutaneous 
areolar  tissue,  and  most  numerously  on  the  fingers  and  toes,  parti- 
cularly on  the  third  phalanx.  There  are  about  600  in  the  hand, 
and  not  quite  so  many  in  the  foot.    (Fig.  286.)     They  are  always 


'  From  I'acini,  wlio  di.-^covcrcd  them  in  1840. 


SPINAL    NERVES. —  PACINIAN    BODIES. 


443 


found,  also,  in  the  sympathetic  plexus  in  front  of,  and  close  to, 
the  abdominal  aorta,  behind  the  peritoneum,  especially  near  the 
pancreas;  frequently  in  the  mesen- 
tery close  to  the  intestine;  and 
occasionally  on  the  internal  pudic 
nerve,  on  the  glans  penis,  the  bulb 
of  the  urethra,  the  intercostal  nerves, 
sacral  plexus,  cutanequs  nerves  of 
the  arm  and  forearm,  the  dorsum 
of  the  hand  and  foot,  and  the  cuta- 
neous nerves  of  the  neck. 

The  Pacinian  bodies  consist  of 
twenty  to  sixty  concentric  layers 
of  connective  (areolar)  tissue;  the 
external  being  separated  by  wider, 
and  the  internal  by  narrower  inter- 
spaces, containing  a  clear  serous 
moisture,  and  which  is  collected  in 
larger  quantity  in  an  elongated 
central  cavity  bounded  by  the  in- 
nermost lamella  (Fig.  287).  A 
rounded  peduncle  formed  from  the 
continuation   of   its    lamellae,   and  ^/C^vr// 

connected  with  a  nervous  twig,  in-  *^^'  /' 

^                       11                        -,1                 1           c  Pacinian  corpuscle,  from  the  mesentery  of 

Closes    a    aark:     nerve-Ilbre,   ^q^q   OI  a  cat;  showing  the  general  construction  of 

an   inch    or    more    in    diameter,   and  these  bodies.    The  stalU  and  body,  the  outer 

,              .      .               -                         .              .  and  Inner  system  of  capsules,  ■vrith  the  cen- 

COnClUCtS  It  mtO    the    central    cavity  tral  cavity,  are  seen.     a.  Arterial  twig  end- 

Of  the  Pacinian  body.       Here  it  be-  ^°S  in  capillaries  which  form  loops  in  some  of 

comes  oo'oo  ^^  ^'^  vaoh  wide,  and 
3^Vo  of  an  inch  thick,  pale,  non- 
medullated,  almost  like  an  axis- 
fibre,  and  terminates  in  the  distal 
part  of  the  cavity  in  a  free,  slightly 
granular  tubercle,  frequently  with  a  bifid  or  a  trifid  extremity. 

^he  function  of  these  bodies  is  still  entirely  unknown. 

5.  The  anastomoses  of  the  branches  of  the  spinal  nerves,  consti- 
tuting the  several  plexuses,  present  no  histological  peculiarities, 
and  may  be  studied  in  the  works  on  descriptive  anatomy. 


the  intercapsular  spaces,  and  one  penetrates 
to  the  central  capsule,  b.  The  fibrous  tissue 
of  the  stalk  prolonged  from  the  perineurium. 
n.  Nerve-tube  advancing  to  the  central  cap- 
sule, there  losing  its  medulla,  and  stretching 
along  the  axis  to  the  opposite  end,  where  it  is 
fixed  by  a  tubercular  enlargement. 


444:  THE   TISSUES. 

2.  The  Ganglionic  Nervfs. 

These  are  usually  included  under  the  designation  of  the  "sym- 
pathetic nerve,"  or  "  nerves  of  organic  life."  They  are  to  be  re- 
garded rather  as  an  appendage  to  the  spinal  nerves,  and  are  hence 
next  to  be  described. 

The  sympathetic  nerve  consists  of  a  whitish  trunk  with  a  series 
of  ganglia  (Fig.  282,  s)  upon  it ;  into  which  branches  pass  from  the 
spinal  nerves  (the  rami  communicantes.)  In  the  chest  and  abdo- 
men, these  ganglia  and  the  main  nerve  are  situated  on  each  side  of 
the  spinal  column. 

We  have  to  consider: — 

A.  The  connecting  branches. 

B,  The  ganglia,  and  their  fibres, 

A.  The  rami  communicantes  rise  from  the  trunks  of  the  spinal 
nerves  immediately  after  they  are  formed  by  the  junction  of  the 
anterior  and  posterior  roots.  They  contain  both  the  coarse  and  the 
fine  nerve-fibres,  but  always  a  preponderance  of  the  latter;  of  which 
a  portion  may  be  derived  from  the  spinal  ganglia.  They  may  thus 
be  regarded  as  the  roots  of  the  sympathetic.  Possibly  they  are 
derived  in  some  small  degree  from  the  sympathetic  itself  also;  the 
fibres  from  the  latter  source,  however,  entering  the  main  trunk  with 
the  rest. 

Having  entered  the  trunk  of  the  sympathetic,  the  communicating 
branches  run  both  upwards  and  downwards  in  it,  towards  its  ce- 
phalic and  pelvic  extremities.  Finally,  they  doubtless  go  ofi"  to  be 
•distributed  in  its  peripheral  branches;  since  all  the  latter  frequently 
contain  the  same  dark-bordered  thicker  fibres. 

B.  The  ganglia  of  the  sympathetic  have  essentially  the  same 
structure  as  the  spinal  ganglia.  They  consist  (1)  of  perforating 
nerve-fibres,  proceeding  from  one  part  of  the  trunk  to  the  other, 
besides  those  of  the  rami  communicantes;  (2,)  of  numerous  gan- 
glion-cells, and  (3)  of  ganglion- fibres  originating  from  the  last. 
(Fig.  288.) 

1.  The  perforating  fibres  require  no  special  description. 

2.  The  gnnglion-cells  precisely  resemble  those  in  the  spinal  gan- 
glia (Fig.  284),  except  that  they  are,  on  an  average,  smaller;  being 
?ooo  to  Ta'oc  o^  ^^  ^^^^  i'^  diameter,  with  less  and  paler  pigment, 
or  even  none  at  all ;  and  usually  pretty  uniformly  rounded.     Cells, 


GANGLIONIC   NERVES. 


445 


however,  exist  in  the   spinal  ganglia  as  FiR-  288. 

small  as  any  found  here.     On  the  other 

hand,  some  of  these  measure  even  ^^^ 

of  an   inch.     They  are  mostly  unipolar, 

and  very  rarely  bipolar.     Apolar   cells 

are  also  more  abundant  than  in  the  spinal 

ganglia.  (Fig.  289.) 

3.  The  ganglion-fibres  arc  of  the  finest 
kind,  joirut)  to  ^^'q^  of  an  inch  in  diame- 
ter. They  are  dark -bordered,  but  pale. 
They  constitute  a  large  proportion  of  the 
sympathetic  trunk,  and  its  branches,  but 
are  in  no  respect  peculiar  to  it,  as  has 
been  shown  (p.  429).  The  existence  of 
these  fibres  does  not  confer  a  special  func- 
tion on  the  sympathetic  nerve,  and  which 
does  not  exist  elsewhere ;  though  they 
may  manifest  a  peculiar  function  wher- 
ever found^  whether  in  the  sympathetic 
or  the  spinal  nerves. 

The  "  fibres  of  Remak"  which  have 
already  been  described,  also  enter  into 
the  structure  of  the  peripheral  branches 
of  the  sympathetic  nerves ;  and  some- 
times constitute  three-fourths  or  even 
nine-tenths  of  the  branch  (p.  429). 

A  great  number  of  ganglia  also  occur 
on  the  peripheral  branches  of  the  sympa- 
thetic, some  of  them  of  merely  micro- 
scopic dimensions.  They  have  a  struc- 
ture like  that  before  described,  and  the  ganglion- cells  give  off  new 
fibres,  so  that  the  emergent  branches  always  contain  an  increase  of 
them.     In  these  also  many  of  the  cells  are  apolar. 

How  are  the  fibres  of  the  sympathetic  finally  distributed  ? 

1.  The  fibres  terminate  by  division  in  some  cases;  e.  g.  the  nerves 
of  the  spleen,  in  the  Pacinian  bodies  of  the  mesentery,  in  the  nerves 
temporarily  existing  in  the  uterus  of  the  rodentia,  and  those  of  the 
ilura  mater  on  the  meningeal  arteries,  &c.  2.  There  are  free  ter- 
minations of  the  fibres;  as  in  the  Pacinian  bodies,  and  the  mesen- 


Sixth  thoracic  ganglion  on  the 
left  side  of  the  sympathetic  nerve 
of  the  rabbit,  seen  from  behind,  and 
treated  with  soda.  (JIagnifled  40 
diameters.)  T2.  Trunk  of  the  sym- 
pathetic. Re,  Re.  Rami  commn- 
nicantes,  each  dividing  into  two 
branches.  Spl.  Splanchnic  nerve. 
S.  Twigs  of  the  ganglion  with  two 
stronger  fibres  and  finer  filaments 
probably  going  to  vessels.  G.  I\"er  ve- 
cells  and  ganglion-fibres  joining 
the  main  trunk,  g.  Ganglion-cells. 
(KdlWcer.) 


•i48 


THE   TISSUES. 


Fig.  289. 


Apolar  nerve-cells  from  the 
cardiac  ganglia  of  the  frog  ; 
one  within  the  origin  of  a 
nerve-tube.  —  Magnified  350 
diameters.    (Kolliker.) 


teric  vessels  of  the  frog.  3.  The  thicker 
fibres  become  the  finest  kind,  and  ultimately 
non-medullated  embryonic  fibres,  in  all  pro- 
bability. But  nothing  precise  is  yet  known  re- 
specting their  terminations  in  the  heart,  lungs, 
stomach,  intestine,  kidneys,  spleen,  liver,  ute- 
rus, &c. 

The  many  ^-ilexuses  of  the  great  sympa- 
thetic, and  which  affect  a  relationship  to  the 
aorta  and  its  abdominal  subdivisions,  present 
no  histological  peculiarities. 


3.  The  Encephalic  Nerves. 
The  twelve  pairs  of  nerves  rising  from  the  encephalon  correspond 
(except  the  first,  second,  and  eighth  pairs)  so  closely  with  the  spinal 
nerves  in  most  respects,  that  only  a  brief  description  of  them  is 
here  required. 

All  these  nerves,  except  the  fifth  pair  (trigeminus),  ninth  (glosso- 
pharyngeal), and  tenth  pair  (pneumogastric),  and  perhaps  the  ele- 
venth (spinal  accessory)— rise  from  a  single  root  instead  of  two; 
and  are,  therefore,  exclusively  motor  or  exclusively  sensory.     The 
ffth  pair  is,  however,  histologically  and  physiologically  a  spinal 
nerve;  and  for  the  description  of  its  ganglion  (the  Gasserian),  and 
its  final  distribution,  we  refer  to  the  spinal  nerves.     Several  gan- 
glia are,  however,  placed  upon  it  (submaxillary,  &c.),  as  upon  the 
sympathetic;  and  they  present  the  same  structure  also  as  the  latter, 
except  that  they  contain  a  considerable  number  of  larger  nerve, 
cells.     The  ninth  pair  (glosso-pharyngeal),  though  endowed  with 
motor  properties,  has  no  fibres  which  do  not  pass  through  the  one 
or  the  other  of  its  ganglia.     Its  ultimate  ramifications  in  the  tym- 
panic cavity  and  in  the  tongue,  contain  small  ganglia.     The  teiiUt 
pair  (pneumo-gastric)  has  all  its  roots  enter  the  jugular  ganglion 
in  man ;  while  in  several  lower  animals  (dog,  cat,  rabbit,  &c.),  it  has 
a  primary  fasciculus  not  connected  with  the  ganglion.     The  latter 
presents  no  peculiarity,  except  that   the  nerve-cells  occasionally 
measure  only  xa'sa  o1  an  inch,  though  there  are  many  as  large  as 
-J(f^  of  an  inch.     The  ultimate  distribution  of  this  nerve  exhibits  a 
constant  separation  of  thicker  from  more  slender  fibres;  so  that  the 
branches  to  the  oesophagus,  heart,  and  stomach  are  composed  almost 
entirely  of  fine  fibres;  while   in  those  going  to  the  lungs,  and  in 


ENCEPHALIC   NERVE 


447 


the  superior  laryngeal  nerves,  the  finer  are  to  the  thick  only  as  2  to  1. 
On  the  other  hand,  in  the  inferior  laryngeal  nerves  and  the  pharyn- 
geal branches,  the  thick  fibres  are  to  the  fine  as  6,  or  even  10,  to  1. 
All  these  fine  fibres  are  not,  however,  derived  from  the  great  sym- 
pathetic; but  mostly  from  the  ganglion-cells  on  the  original  roots  of 
this  nerve.  (KoUiker.)  The  eleventh  pair  (accessory  of  Willis)  is 
perhaps  also  in  part  sensitive;  but  has  no  cells,  and,  so  far  as  is 
known,  presents  nothing  peculiar. 

The  7>2otor  encephalic  nerves  are  the  third  pair  (oculo-motores) ; 
fourth  pair  (patheticus) ;  sixth  pair  (motor  externus) ;  seventh  pair 
(facial),  and  twelfth  pair  (hypoglossal).  All  these  present  the  same 
conditions  as  the  anterior  roots  of  the  spinal  nerves,  except  that  all 
of  them  anastomose  with  sensitive  nerves,  and  thus  carry  sensitive 
as  well  as  motor  fibres  to  the  muscles.  A  ganglion  is  also  found 
in  the  facial  nerve  (intumescentia  gauglioformis) ;  and  also  on  the 
third  pair  in  the  ox,  according  to  Eosenthal  and  Purkinje.  This 
occurrence  of  new  cells  in  motor  nerves  is  not  yet  explained. 

Terminal  loops  within  the  trunks  of  the  encephalic  nerves  had 
been  noticed  by  Gerber,  and  since  by  Valentin.     Their  significa- 


Fig.  290. 


Outer  wall  of  tlie  nasal  fossa  with  the  throe  spongy  bones  and  meatus  ;  the  nerves  being  sliown  as 
they  would  appear  through  the  membrane  if  it  were  transparent,  a  Olfactory  process,  b.  Olfac- 
tory bulb  (represented  rather  too  short),  resting  on  the  cribriform  plate.  Below  is  seen  the  plexi- 
form  arrangement  of  the  olfactory  filaments  on  tlie  upper  and  middle  spongy  bones,  c.  Fifth  nerve 
within  the  cranium  with  its  Gasserian  ganglion,  d.  Its  superior  maxillary  division,  sending 
branches  to  Meckel's  ganglion,  and  through  that  to  the  three  spongy  bones,  where  they  anastomose 
with  the  olfactory  filaments,  and  with  (s)  brandies  of  the  nasal  division  of  the  ophtlialmic  nerve, 
o.  Posterior  palatine  twigs  from  Meckel's  ganglion  supplying  the  soft  and  hard  palate,  t.  Oriflce 
of  the  Eustachian  tube.     From  Soimmering;  two-thirds  diameter. 


U8 


THE   TISSUES. 


tion  is  unknown ;  as  is  also  that  of  the  nervous  filaments  seen  by 
Eemak  and  Bochdalek,  coming  out  from,  and  again  re-entering  the 
brain. 

The  three  remaining  encephalic  nerves  are  nerves  of  sjjecial  sen- 
sation ;  viz.,  the  first  pair  (olfactory),  the  second  pair  (optic  nerves), 
and  the  eighth  pair  (acoustic). 

1.  The  first  jKiir  is  the  nerve  of  smell.  The  portionof  this  nerve 
lying  on  the  cribriform  plate  of  the  ethmoid,  is  called  the  bulb;  and 
the  rest,  extending  from  this  to  the  cerebrum,  the  tract.  Both  these 
are  made  up  of  the  common  dark-bordered  nerve-fibres. 

The  branches,  on  the  other  hand,  which  are  given  off  from  the 
bulb  into  the  upper  portions  of  the  nasal  passage  (Fig.  290),  con- 
tain no  white  medullated  fibres  at  all;  but  are  constituted  of  pale, 
slightly  granular,  flattened  fibres  (Fig.  291,  6),  g  Jqu  to  -^-^-qq  of  an 
inch  wide,  with  elongated  nuclei  retained  closely  in  connection  by 
common  sheaths  of  connective  tissue,  which  are  thicker  in  the 
branches  to  the  septum.  (Fig.  292.)     In  the  bulb,  however,  nerve- 


Fig.  291. 


Fig.  292. 


Fig.  2!>1.  From  the  naHal  raucovis  inombrane  of  tho  slipep.  1.  From  the  regio  olfndoria,  traus- 
verse  snction  of  the  mucous  membrane;  a,  epithelium  without  cilia;  6,  olfactory  nerves,  with  a 
dividing  pale  nucleated  fasciculus;  c,  one  of  "Bowman's  glands;"  d,  its  orifice.  2.  Ciliated  epi- 
thelium of  the  Schneiderian  membrane. — Magnified  .'WO  diameters.     (KUWcer.) 

Fig.  202.  Nerves  of  the  septum  of  tho  nose.  a.  Olfactory  bulb  resting  on  the  cribriform  plate, 
below  wliith  its  branches  may  be  traced  on  the  septum  about  half  way  down.  Behind,  t)ie  naso- 
palatine nerve  from  Mecl<el's  ganglion  is  seen  descending  to  tho  uaso-])alatine  canal.  In  front,  tho 
nasal  twig  of  the  ophthalmic  nervo  descends  towards  the  tip  of  tho  nose,  dividing  into  two  principal 
branches,  'p.  Hoof  of  the  mouth,  e.  Orifice  of  the  Eustachian  tube. — Magnified  one-half  diameter. 
{Arnold.) 


ENCEPHALIC   NERVES. 


449 


cells  of  TsaiTTT  to  -^-ij^-g  of  an  inch,  many  with  branched  fibres,  are 
found  among  the  nerve-fibres.  The  latter  very  closely  resemble 
the  embryonic  nerve-elements,  and  are  probably  derived  from  the 
olfactory  bulb,  and  not  from  the  cerebrum  itself.  It  is  doubtful 
how  they  terminate.  The  surface  over  which  they  are  distributed, 
called  the  "  olfactory  region,"  extends  only  f  to  1  inch  below  the 
lamina  crihrosa  of  the  ethmoid  bone  (Fig.  200);  and  on  this  surface 
alone  the  epithelium  of  the  mucous  membrane  is  not  ciliated.  (B'ig. 
291.) 

2.  The  second  pair  of  encephalic  nerves  is  the  nerve  of  vision. 
The  optic  nerve  has  its  tract  composed  of  dark-bordered  fibres  ggg^ 
of  an  inch  in  diameter.  In  the  chiasma^  some  of  the  fibres  pass  to 
the  retina  of  the  same  side,  and  some  to  that  of  the  other  side; 
while  others  still,  form  a  loop  in  the  posterior  part  of  the  chiasma, 
and  thus  connect  the  origins  of  these  nerves ;  and  a  fourth  set  are 
looped  in  a  similar  manner  anteriorly  to  connect  the  two  retinae. 
(Fig.  293.)     The  fibres  are  much  disposed  to  become  varicose,  but 


Fig.  293. 


Course  of  fibres  in  the  optic  cliiasraa,  as  exhibited  by  tearing  off  the  superficial  bundles  from  a 
specimen  hardened  in  spirits,  a.  Anterior  fibres  commissural  between  the  two  retin».  2>-  Posterior 
fibres  commissural  between  the  thalami.     a',  p'.  Diagram  of  the  preceding. 

the  nerve-cells  among  them,'  mentioned  by  Hassall,  have  not  been 
found  by  Kolliker.  They  form  polygonal  bundles  gi^  to  ji^  of 
an  inch  in  diameter,  surrounded  by  a  perineurium  of  the  usual 
kind,  and  which  is  replaced  by  the  sclerotica  on  their  reaching  the 
eyeball.  The  fibres  undergo  no  change  till  after  entering  within 
the  sclerotica  and  forming  the  slight  elevation  (coUicvhis  nervi 
optici),  on  the  retina  opposite  its  point  of  entrance.  But  from  that 
point  onwards,  the  fibres  become  perfectly  clear,  yellowish  or  gray- 
ish, and  transparent,  like  the  finest  fibres  in  the  central  organs,  and 


mostly  from 


1 


5  T5  0 1)  0 


to  T5000  of  ^^  inch,  though  some  are  jt^I^jj  to 


gtiVu  of  an  inch 


They,  however,  have  no  nuclei  in  their  course, 
and  are  inclined  to  varicosities  like  the  minutest  fibres  of  the  cere- 
brum. {Kolliker.)     (Figs.  294  and  298,  3.) 
29 


450 


THE   TISSUES, 


These  fibres  radiate  on  all  sides  from  the  colliculus  before  men- 
tioned, and  constitute  a  continuous  membraniform  expansion  ex- 
tending as  far  as  the  ora  serrala  of  the  retina ; 
Fig.  294.  presenting  no  considerable  interruption,  except 

at  the  situation  of  the  macula  lutea,  where  they 
are  almost  wholly  wanting.  In  this  expansion 
the  fibres  are  associated  into  compressed  bun- 


dles 


)  1  Sou 


■hts  to 


Tc'cu  of  ^Q  iiich  wide,  either  anas- 
tomosing with  each  other  at  very  acute  angles, 
or  lying  parallel  for  considerable  distances.    It 
is  3^3  of  an  inch  thick  at  the  bottom  of  the  eye, 
and,  gradually  decreasing,  only  g^Vo  ^^^ar  the 
ora  seirata,  or  anterior  termination.   How  these 
fibres  terminate,  is  still  unknown.  (Fig.  295,  1.) 
The  expansion  of  the  optic  nerve  just  de- 
scribed by  no  means  constitutes  the  retina,  how- 
ever.  The  latter  consists  of  five  distinct  layers,  of  which  this  expan- 
sion constitutes  one.     These  are  from  within  outwards.    (Fig.  295.) 

Fig.  295. 


P  m" 


Fragments  of  nerre-tu- 
bules  from  the  human  optic 
nerve,  of  various  sizes,  and 
varicose.  At  a  the  axis- 
fibre  projects  beyond  the 
medulla  at  a  broken  extre- 
mity. (Magnified  320  dia- 
meters.) 


I^i.:[lj(r^^r:i\fi^^^^^ 


Vertical  section  of  liuman  retina  and  hyaloid  membrane,  h'.  Nuclei  on  inner  surface  of  latter.  /(. 
Limitary  membrane,  c.  Layer  of  transparent  (epitliolial  ?)  cells,  c'.  Separate  cell,  enlarged  by 
action  of  water,  n.  Gray  nervous  layer,  with  its  capillaries.  1.  Fibrous  layer  (optic  nerve).  2. 
Gray  vesicular  layer.  1'.  Shred  of  fibrous  lamina,  detached.  2'.  Cell  and  nucleus,  detached.  //. 
Granular  layer.  3.  Light  lamina,  frequently  seen.  g'.  Detached  nucleated  particle  of  granular 
layer,  r/i.  Jacobson's  membrane,  m'.  Its  bacilli,  detached,  m".  Its  outer  surface.  (JIaguified  .320 
diameters.) 

1.  The  limitary  membrane. 

2.  The  expansion  of  the  optic  nerve. 
8.  The  layer  of  gray  nerve-substance. 

4.  The  granular  layer. 

5.  The  bacillar  layer  (rods  and  cones). 


ENCEPHALIC   NERVES. 


451 


Fig.  296. 


1.  The  limitary  membrane,  7t,  is  merely  a  simple  membrane,  ^ihvT! 
of  an  inch  thick.  Its  inner  surface  presents  towards  the  hyaloid 
membrane  of  the  vitreous  body.  On 
its  outer  surface  Todd  and  Bowman 
found  a  layer  of  epithelial  (?)  cells  (c), 
but  which  Kolliker  has  not  seen. 

2.  The  next  layer — the  expansion 
of  the  optic  nerve  (1) — has  just  been 
described  (p.  450). 

8.  The  layer  of  gray  cerehral  sub- 
stance (2)  penetrates  between  the  fibres 
of  the  optic  nerve,  but  is  quite  well 
defined  on  its  outer  surface.  It  is  com- 
posed of  a  finely  granular  matrix, 
exactly  resembling  that  in  the  gray 
substance  on  the  surface  of  the  cere- 
brum and  cerebellum;  containing  nu- 
merous scattered  nerve-cells.  Some 
of  the  latter,  in  the  outer  half  of  this 
layer,' are  small  (goVcr  to  50V  o^  of  ^^ 
inch);  others,  in  the  inner  portion, 
3^V^  to  7^0  of  an  inch.  They  have  from  two  to  six,  or  more,  pale 
branched  processes  (Fig.  296),  like  those  of  the  central  nerve-cells; 
these  processes  being  at  first  g oVo  of  an  inch  in  diameter,  but  di- 
minishing in  repeated  divisions  to 
scarcely  30000  of  an  inch.  They  ap- 
pear always  to  be  given  off  towards 
the  exterior,  but  curve  so  as  to  ramify 
in  the  gray  layer  itself.  Its  entire 
thickness  varies  at  points  from  g  J^^ 
to  54'o^  of  an  inch.  The  distribution 
of  its  capillaries  is  shown  by  Fig,  297. 

4.  The  granular  layer  (Fig.  295, 
g).  In  man,  the  granules  are  dis- 
posed throughout  most  of  the  retina 
in  two  layers — an  internal,  thinner 
(•2o'o 0  to  135^  of  an  inch),  and  an  ex- 
ternal, thicker  (ij^a  to  ^^^  of  an  inch). 
Between  these  is  a  clear,  finely  granular,  and  somewhat  vertically 


Nerve-cells  -witli  processes,  from  the  re- 
tina of  the  ox. — Magnified  350  diameters. 
{KiMiker.) 


Fig.  297. 


Distribution  of  capillaries  in  the  vascular 
(gray)  layer  of  the  retina. 


striated  layer  (3),  5 


TiOIJ 


to  YBo^  of  an  inch  thick. 


Towards  the  ora 


serrata^  however,  the  two  form  a  single  structure  of  not  more  than 


452 


THE   TISSUES. 


SUliO 


of  an  inch  thick.  The  granular  bodies  themselves  are  round 
or  oval,  and  g^'^^j  to  g^'^o  ^^  ^^  i^°^  i^  diameter,  with  very  fine 
filaments  extending  from  both  sides,  of  g^^nij  to  4  0^75^  of  an  inch, 

5.  The  external  layer  of  the  retina  is  the  hacillar  layer,  or  Jacob- 
son's  membrane  (m).  Its  structure  is  very  remarkable,  presenting  two 
elements — the  rods  (bacilli)  and  the  cones  (coni) — blended  together 
in  a  single  layer,  3^3  of  an  inch  thick  at  the  bottom  of  the  eye,  g^^ 
more  anteriorly,  and  quite  in  front  not  more  than  g^^  of  an  inch. 

The  rods  are  cylindrical,  slender,  elongated  corpuscles,  consisting 
of  two  portions,  the  larger  external  end,  or  proper  rod,  and  the 
internal,  or  filament.  The  former  is  a  cylinder  ygV^  to  g^^  of  an 
inch  long,  and  xs^o^  of  ^"^  i^ch  broad,  and  truncated  at  the  outer 
end;  while  the  inner  is  produced  into  a  short  point,  ^oVo  to  4o'oo 
of  an  inch  long  from  the  inner  extremity  of  the  rod ;  is  of  uniform 
width,  and  extends  through  the  inner  half  of  the  bacillar  layer. 
The  substance  of  the  rods  is  clear  and  homogeneous,  with  a  faint, 
glistening,  fatty  aspect,  and  is  very  soft,  flexible,  and  fragile.   They 

Fig.  298. 


Retinal  elements  of  man.  1.  "Rods"  and  radiating  fibres:  Tc,  proper  "rod;"  r,  prolongation  of 
ItB  pointed  inner  extremity  ;  h,  "granule"  (cell)  of  the  outer  granular  layer  ;  I,  enlarged  extremity 
of  the  radiating  fibres,  proceeding  from  them  to  the  surface  of  the  optic  layer ;  k' ,  "rod"  seated  on 
a  "cone"  (i) ;  r",  fibre  proceeding  from  the  latter,  connected  with  the  "grannie"  (/)  of  the  inner 
granular  layer,  and  the  terminal  enlargement  (I)  on  the  inner  surface  of  the  retina  ;  w,  one  of  the 
fibrous  bundles  in  tvliich  the  radiating  fibres  fre(iuently  terminate  at  tlieir  innermost  extremity.  2. 
Rods  torn  from  their  fibres.  3.  Fibres  of  optic  nerve  ;  c,  fine — a  and  h,  varicose.  4.  Two  cones  torn 
from  their  processes,  d;  with  attached  rod,  a,  at  outer  end  ;  c,  nucleus. — Magnified  350  diameters. 
(KiMiker.) 


ENCEPHALIC   NERVES. 


453 


Fig.  299. 


are  much  altered  by  all  reagents;  and  a  very  common  change  con- 
sists in  their  end  presenting  a  hook-like  curve  or  a  slight  enlarge- 
ment.    (Figs.  298  and  295,  m'.) 

The  cones  may  be  regarded  as  rods  terminating  internally  in  a 
conical  or  pyriform  body  (instead  of  a  filament),  whose  length 
equals  one-half  the  thickness  of  the  bacillar  layer,  and  its  breadth 
being  5555  to  je'ss  of  ^^  inch.  Each  of  these  cones  has  an  exter- 
nal thicker  and  larger,  finely  granular  extremity,  often  ventricose, 
gradually  diminishing  in  size,  and  passing  into  a  common  rod  with- 
out a  point ;  and  a  shorter  inner  portion,  inclosing  an  elongated  or 
pyriform,  more  opaque,  and  brilliant  body, 
suu'O  *o  4  oV 0  of  an  inch  long.  Kcilliker,  how- 
ever, sees  in  these  cones,  as  just  described, 
only  a  cell  with  a  nucleus.    (Fig.  298,  4.) 

The  rods  and  cones  are  arranged  vertically 
upon  the  retina,  like  palisades  in  close  appo- 
sition, one  of  their  ends  being  directed  to- 
wards the  choroid  membrane,  and  the  other 
towards  the  granular  layer.  The  appearance 
of  the  cones  and  rods  when  the  bacillar  layer 
is  seen  from  without  (the  cones  alone  existing 
over  the  macula  lutea),  is  shown  by  Fig.  299. 

3.  The  eighth  fair  is  the  nerve  of  hearing. 
The  acoustic  nerve  is  composed  of  fibres  g o'do 
to  24V0  of  an  inch  in  diameter,  which  are  very 
easily  destroyed,  and  are  invested  by  a  very 
delicate  perineurium.  Hence  it  has  been 
called  the  iwrtio  mollis.  Among  these  fibres  in  the  trunk,  and  in 
both  the  vestibular  and  cochlear  branches,  there  occur  numerous 
apolar,  unipolar,  and  bipolar  cells,  gi^  to  y^i  of  an  inch  in  diame- 
ter. KoUiker  suggests  that  the  first  two  kinds  are  truncated  bipolar 
cells.  Similar  but  smaller  cells  are  also  found  in  the  cochlea,  as 
well  as  in  the  nervous  twigs  in  the  vestibule. 

The  vestibular  nerves  finally  break  up  into  a  rich  bundle  of  smaller 
and  frequently  anastomosing  branches,  which  appear  to  terminate 
ultimately  in  fine  twigs  composed  of  from  two  to  ten  primitive 
fibres,  Ysoocy  ^o  goVtr  of  an  inch  thick.  In  the  sacculns  we  find  the 
otoliths  in  immediate  relation  with  the  nervous  expansion.  These 
are  composed  of  innumerable  hexahedral  prisms  of  carbonate  of 
lime. 


Bacillar  layer  from  without. 
1.  At  the  "  yellow  spot"  (only 
cones).  2.  At  the  herder  of 
the  same.  3.  From  the  mid- 
dle of  the  retina,  a.  "Cones," 
or  vacuities  corresponding 
with  them.  b.  "Rods"  of  the 
"  cones,"  whose  terminal  sur- 
face is  often  placed  rather 
more  deeply  than  that  of  the 
proper  "rods,"  e. — Magnified 
330  diameters.   (KClliker.) 


454 


THE   TISSUES. 
Fig.  300. 


A  highly  niaguifled  view  of  a  small  jjiece  of  the  lamina  spiralis,  showing  the  manner  in  which  the 
nerves  leave  their  perineuriiim  as  they  anastomose ;  the  natural  size  of  the  piece  is  seen  on  the  side 
of  the  figure.  1.  Portion  of  the  auditory  nerve.  2,2.  Osseous  canals  in  the  zona  ossea  of  the  lamina 
spiralis.  3,  3.  Anastomoses  in  the  zona  mollis.  4,  4.  The  neurilemma  leaving  the  nervous  loops, 
and  expanding  into  the  zona  membrauacea. 


301. 


Bipolar  ganglion-cell 
from  the  zonula  ossea  of 
the  lamina  spiralis  of 
the  pig. — Magnified  350 
diameters.  (After  C'orft.) 


The  cochlear  72ert;e,  having  entered  the  cavity  of 
the  osseous  zone  from  the  canal  of  the  modiolus, 
forms  a  plexus  (Fig.  800)  of  dark-bordered  fibres, 
goVo  of  a^^  inch  in  diameter,  containing  an  aggre- 
gation, at  a  definite  spot,  of,  at  first,  ji^  of  an 
inch  wide,  of  bipolar,  oval,  minute  (yy'go  ^^  ^f  o 
of  an  inch),  and  pale  ganglion-cells ;  and  which 
probably  intercept  all  the  fibres  of  the  cochlear 
nerves  in  their  course.   (Fig.  301.) 

The  dark-bordered  fibres  proceeding  from  the 
external  side  of  these  cells  are  again  disposed 
in  anastomosing,  and  afterwards  in  parallel  flat- 
tened bundles.  The  fibres  actually  terminate  by 
being  pale,  Ts^Tytr  of  ^^  i'^^til^  i^^  diameter,  and 
finer;  and  then  ceasing,  there  being  no  loops. 
{Gorti) 

Thus  both  the  auditory  and  the  optic  nerves 
have  a  ganglion  at  their  periphery,  which  proba- 
bly receives  the  impressions,  while  the  nerve- 
fibres  merely  serve  to  conduct  them  to  the  brain. 


STRUCTURE  OF  THE  NERVOUS  CENTRES. 


455 


II.  Structure  of  the  Nervous  Centres. 

The  nervous  centres  are — 

1.  The  spinal  cord. 

2.  The  encephalon:  consisting,  1st,  of  the  medulla  oblongata  and 
the  pons  Varolii;  2dhj,  the  cerebellum;  3cZ/y,  the  cerebral  ganglia- 
and,  4:tJdf/,  the  cerebral  hemispheres. 

The  centres  consist  of  the  white  and  the  gray  nerve-substance 
combined ;  the  former  being  made  up  of  nerve-fibres  alone  (and 
vessels),  the  latter  of  nerve-cells  and  nerve-fibres  combined,  toge- 
ther with  (in  the  cerebellum  and  cerebral  hemisphere)  a  granular 
substance  and  free  nuclei.  The  gray  substance  is  also  abundantly 
supplied  with  vessels.  The  whole  cerebro-spinal  axis  {i.  e.  the  cen- 
tres just  mentioned)  is  also  enveloped  by  th.ree  distinct  membranes; 
which  will  be  considered  after  the  structure  of  the  former  has  been 
described  (p.  468). 


Fig.  302. 


Transverse  section  of  human  spinal  cord  through  the  middle  of  the  lumbar  enlargement,  showing 
on  the  right  side  the  course  of  the  nerve-roots,  and  on  the  left  the  position  of  the  principal  tracts  of 
vesicular  matter.  A,  A.  Anterior  columns.  P,  P.  Posterior  columns.  X,  L.  Portion  of  lateral 
columns,  a.  Anterior  median  fissure,  p.  Posterior  median  fissure,  b,  h,  b,  b.  Anterior  roots  of 
spinal  nerves,  c,  c.  Posterior  roots,  d,  d.  Tracts  of  vesicular  matter  in  anterior  column,  e.  Tracts 
of  vesicular  matter  in  posterior  column.   /.  Spinal  canal,  not  normal,    g.  Substantia  gelatinosa. 


456  THE   TISSUES. 

I.  Structure  of  the  Spinal  Cord. 

While  the  white  substance  of  the  cord  is  composed  almost  exclu- 
sively of  nerve-fibres,  the  gray  portion  is  formed,  in  almost  equal 
proportions,  of  nerve-fibres  and  cells.  A  section  of  the  cord  shows 
the  gray  matter  forming  a  column  in  the  central  part  of  each  half  of 
the  cord  (Fig.  302),  whose  transverse  section  is  of  a  crescentic  form, 
its  two  extremities  being  termed  the  anterior  and  the  posterior  horns. 
The  white  substance  surrounds  and  incloses  the  gray  on  every  side, 
except  towards  the  median  line,  where  the  gray  matter  projects 
through  the  white,  and  thus  comes  into  contact  from  the  opposite 
sides,  constituting  the  graTj  commissure.  This  does  not  normally,  in 
man,  contain  any  canal  in  its  centre,  but  is  constituted  principally 
of  nerve-cells  of  a  yellowish  color,  and  is  called  the  substantia  grisea 
centralis.  The  white  matter  in  the  two  halves  of  the  cord  merely 
comes  nearly  into  contact  behind  the  gray  commissure;  but  in  front 
of  the  latter  it  is  continuous  from  one  side  to  the  other,  constituting 
the  anterior  or  white  commissure.  The  portion  of  each  half  of  the 
cord  between  the  anterior  median  fissure  and  the  anterior  roots  of 
the  spinal  nerves,  is  termed  the  anterior  column;  that  between  the 
posterior  median  fissure  and  the  posterior  roots,  the  posterior  co- 
lumn; and  the  remaining  portion  between  the  anterior  and  posterior 
roots,  the  lateral  column.  At  the  extremity  of  the  posterior  horns 
of  the  gray  matter  is  a  more  transparent  layer,  containing  a  prepon- 
derance of  smaller  nerve-cells — the  substantia  gelatinosa  of  Roland. 
The  gray  columns  vary  considerably  in  their  size  and  form  in  dif- 
ferent parts  of  the  cord,  as  shown  by  transverse  sections ;  it  being 
most  abundant  in  the  lumbar,  and  next  in  the  cervical  region. 

1.  On  examining  the  intimate  structure  of  the  cord,  we  find  in 
the  ivhite  matter  two  sets  of  fibres,  the  longitudinal  and  the  hori- 
zontal, or  transverse. 

The  longitudinal  fibres  are  found  in  all  situations  except  the  ante- 
rior commissure,  are  unmixed  with  horizontal  fibres  in  every  part,* 
as  a  rule,  and  every  where  run  parallel  to  each  other,  without  either 
interlacement  or  being  collected  into  smaller  fasciculi.  They  in- 
crease from  below  upwards,  since  they  successively  pass  inwards 
towards  the  gray  matter  in  their  descent.  They  average  g^'^^j  to 
I  BOO  ^^  ^"^  'mQ\  and  the  size  of  each  fibre  remains  very  nearly  the 
same  in  the  white  substance;  no  divisions  or  other  alterations  in 
diameter  being  found.     These  fibres  are  probably  continuous  with 


STRUCTURE    OF   THE    SPINAL    CORD.  457 

the  horizontal  fibres  next  to  be  mentioned,  being  intermediate  be- 
tween the  latter  and  the  fi.bres  of  the  cerebrum. 

The  transverse  or  horizontal  fibres  occur,  l-s/,  in  the  lateral  and 
posterior  columns  adjoining  the  horns  of  the  gray  substance;  2dly, 
in  the  white  commissure;  and,  Zdly^  at  the  point  of  entrance  of  the 
roots  of  the  nerves.  The  first  will  be  described  with  the  gray  sub- 
stance,— The  fibres  in  the  while  commissure  come  from  the  anterior 
columns,  and,  bending  obliquely  inwards,  cross  in  front  of  the  gray 
commissure  to  the  opposite  side.  The  white  commissure  is  thus  a 
decussation  of  the  anterior  column,  and  not  a  commissure,  as  gene- 
rally understood.  The  decussing  fibres  measure  toooo  to  4c/ou  of 
an  inch,  and  decrease  as  they  diverge  in  the  anterior  horns  of  the 
gray  matter, — The  fibres  in  the  roots  of  the  spinal  nerves  are  con- 
tained in  larger  fasciculi,  either  horizontal,  or  slightly  ascending 
between  the  longitudinal  fibres  to  enter  the  anterior  and  posterior 
horns  of  the  gray  matter,  where  we  shall  again  meet  them.  The 
fibres  do  not  all  communicate  with  the  longitudinal;  and  in  their 
posterior  roots  about  two-thirds  of  them  measure  gx^Vo  ^o  ysVir  of 
an  inch,  and  one-third  of  them  xoV o  to  4 oVo  of  an  inch.  In  the 
anterior  roots  about  three-fourths  of  the  fibres  measure  from  2  oVtt 
to  yo^T  of  an  inch,  and  one-fourth  of  them  gxyVo  to  4oVu  of  an 
inch.  They,  however,  constantly  decrease  in  size  as  they  proceed 
through  the  white  matter,  and  when  they  enter  the  gray  matter  the 
motor  fibres  are  only  ■§  oVo  to  ooVo  of  an  inch,  while  the  sensory 
are  but  xu^tyTy  to  4  o^^  of  an  inch. 

2.  The  nerve-fibres  of  the  gray  substance  of  the  cord  are  very 
numerous,  constituting,  in  any  case,  one-half  of  its  bulk,  or  more. 
They  present  the  same  characters  as  the  fibres  of  the  white  sub- 
stance, except  that  they  are  not,  on  the  average,  more  than  one-half 
as  thick  (j-g^uo  of  an  inch). 

As  they  pass  among  the  nerve-cells  of  the  gray  matter,  some  of 
the  motor  fibres  have  no  connection  with  the  processes  of  the  cells; 
but  continue  to  run  in  the  anterior  horns  to  the  lateral  parts  of  the 
anterior  commissure,  and  become  continuous  with  the  fibres  of  the 
latter.  Thus  some  of  the  motor  fibres  are  connected  with  the  lon- 
gitudinal fibres  of  the  anterior  columns,  with  a  total  decussation. 
Many  of  the  motor  fibres,  however,  take  no  part  in  this  decussation, 
especially  those  which  enter  the  anterior  horns  most  externally. 
These  penetrate  transversely  to  various  depths  (one-half  or  more), 
then  curve  upwards,  and  finally  appear  as  longitudinal  fibres.   Thus 


458 


THE   TISSUES. 


another  portion  of  tlie  motor  fibres  is  continuous  witli  the  longi- 
tudinal fibres  of  the  same  side,  without  any  decussation. 

It  should  be  added  that  though  the  motor  fibres  diminish  in  size 
after  entering  the  cord,  till  they  enter  the  gray  matter,  where  they 
are  about  goVo-  of  ^^  i^ch  iu  diameter,  they  again  enlarge  as  they 
emerge  from  the  latter,  but  never  so  as  to  attain  their  original  dia- 
meter. 

The  sensitive  roots  also  penetrate  the  white  matter  of  the  cord 
to  the  posterior  horns  of  the  gray  matter,  and  proceed,  without 
any  direct  connection  with  the  nerve-cells,  quite  through  the  si(h- 

stantia  gelatinosa  into  the  suh- 


Fig.  303. 


f/    h 


stantia  grisea.  From  this  point 
some  of  the  fibres  bend  up- 
wards nearly  at  a  right  angle, 
and  proceed  to  become  longi- 
tudinal fibres  in  the  posterior 
columns.  Another  portion  of 
them  penetrates,  in  a  fascicular 
form,  between  the  above-men- 
tioned longitudinal  bundles,  fur- 
ther forwards,  losing  themselves 
in  the  posterior  and  the  lateral 
columns,  and  also  extending 
into  the  gray  commissure  pro- 
bably on  the  opposite  side.  (Fig. 
303.) 

The  sensory  fibres  also  de- 
crease in  size  as  they  traverse 


Vertical  and  an tero-posterior  section  through  the 
cord,  midway  between  the  gray  cornua  and  the  point 
of  entrance  of  the  roots  of  the  nerves,  a.  Posterior 
column,  with  the  sensitive  roots  (h),  traversing  it. 
b.  Substantia  gelatinosa.  c.  Prolongations  of  the  thp  COrd  till  thpv  rpach  the 
posterior  roots,  which  bend  round  in  front  of  the  '      _  *'  _ 

substantia  gelatinosa,  and  run  longitudinally  in  gray  COmmisSUrCS;  bciug  yg'TJ^y 
order  there  to  join  more  particularly  the  posterior  ^^  ^^^  j^_^^|^  -^^  ^j^^  ^^^^^  ^^^^^_ 
column,    a.  Basis  of  the  posterior  cornua,  with  the 

ends  of  the  horizontal  portion  of  the  sensitive  roots  SclvCS,  UCVCr  morC  than  ^  y^TT  of 
apparent  (from  their  being  cut  across),  e.  Anterior 
cornua,  with  the  large  nerve-colls  (the  spots),  and 
also  the  horizontal  and  divided  continuations  of  the 
motor  roots.  /.  Anterior  column  traversed  by  the 
motor  roots  (t). — Magnified  2.J  diameters.  (Ki'Uiker.) 


an  inch  in  the  substantia  gelati- 
nosa, y^^oTj  to  4^Vt;  of  an  inch 
in    the    substantia   grisea,    and 


only  y 


1 


to 


TTTWCiTJ 


of  an  inch 


in  the  gray  commissure.  They,  however,  also  increase  on  leaving 
the  latter,  to  from  yuffTTTT  ^o  -3^)^11  of  an  inch,  and  afterwards  become 
longitudinal  fibres. 

Besides  the  motor  and  sensory  fibres,  there  are  still  others  in  the 


STRUCTURE  OF  THE  SPINAL  CORD. 


459 


Fig.  304. 


gray  substance,  not  referable  to  the  roots,  and  which  for  the  present 
may  be  termed  special  fibres  of  the  spinal  cord. 

The  gray  substance  of  the  cord,  in  addition  to  the  fibres  just  de- 
scribed, contains  cells  presenting  various  forms,  but  all  being  inva- 
riably furnished  with  processes,  which, 
after  repeatedly  branching,  ultimately 
terminate  in  extremely  fine  pale  fibrils, 
like  the  finest  axis-fibres.  Kolliker 
distinguishes  three  classes  of  nerve- 
cells.  1.  The  cells  of  the  central  gray 
substance  (Fig.  304)  measure  -g  oVo  to 
j-gjj-ij  of  an  inch ;  are^  always  pale  and 
granular,  with  multiple  nuclei  and 
branching  pale  processes.  These  con- 
stitute the  principal  bulk  of  the  cen- 
tral gray  substance.  2.  The  cells  of 
the  substantia  gelatinosa  resemble  the 
preceding,  except  that  they  are  of  a 
faint  yellowish  color,  and  have  one 
to  three  processes,  and  simple  nuclei. 
3.  Well-marked  cells  are  seated  espe- 
cially at  the  apex  of  the  anterior  horn 
(Figs.  279,  280),  though  also  occurring 
in  other  portions  of  the  anterior,  and 
in  less  number  in  the  posterior,  horn ; 
while  they  are  never  met  with  in  the  substantia  gelatinosa  and  the 
gray  commissure.  All  these  cells  are  4^^  to  5^0  of  an  inch  in 
diameter,  with  nuclei  of  34^x0  to  tsVo  ^f  ^"^  inch;  frequently  con- 
tain brown  pigmentary  matter,  and  have  from  two  to  nine  or  even 
more  branched  processes,  3  oVtt  to  34^7  of  ^^  vcioh  in  diameter  at 
their  origin.  These  processes  may  be  traced  to  a  length  of  yij^  to 
■^-^  of  an  inch,  and  terminate  in  fine  fibrils,  scarcely  more  than 
s^^TjTT  of  an  inch  thick,  all  of  which  are  contained  within  the  gray 
substance. 

Do  the  nerve-fibres  of  the  roots  of  the  spinal  nerves  terminate 
in  the  white  and  gray  matter  of  the  cord?  or  do  they  all  ascend  to 
the  brain?  Volkmaun  maintains  that  they  terminate  in  the  cord, 
and  has  carried  most  physiologists  with  him.  We,  however,  regard 
Kolliker's  reasons  for  the  belief  that  they  proceed  to  the  brain,  as 
far  more  satisfactory.  That  the  nerve-fibres  become  attenuated  on 
entering  the  cord,  has  already  been  shown.     And  the  further  fact 


Cells  from  tlie  gray  central  substance  of 
the  cord  in  man. — Magnified  350  diame- 
ters.   (Ki'lliker.) 


460 


THE   TISSUES. 


that  the  white  substance  of  the  cord  constantly  increases  from  be- 
low upwards,  and  that  the  enlargements  of  the  cord  depend  mainly 
upon  the  gray  substance,  has  an  important  bearing  on  this  question. 
Moreover,  no  connection  has  been  discovered  between  the  nerve- 
fibres  in  the  cord,  and  the  processes  of  the  cells  of  its  gray  matter. 
Still,  it  by  no  means  follows  that  these  cells  may  not  act  on  the 
fibres  sent  among  them;  and  experimental  physiology  at  present 
demands  the  admission  that  they  do  impart  motor  impulses  to  them, 
at  least  in  the  production  of  reflex  or  diastaltic  motions. 

II.  Structure  of  the  Encephalon. 
1.  The  Medulla  Oblongata  and  Pons  Varolii. 
The  medulla  oblongata  and  pons  Varolii  constitute  a  very  import- 
ant part  of  the  encephalon,  since  ten  of  the  twelve  pairs  of  encepha- 

Fig.  305. 


Transverse  section  of  the  medulla  oblongata  through  the  lower  third  of  the  olivary  bodies.  (From 
Stilling.)  a.  Anterior  fissure,  b.  Fissure  of  the  calamus  scriptorius.  c.  Kaph^.  d.  Anterior  co- 
lamns.  e.  Lateral  columns.  /.  Posterior  columns,  g.  Nucleus  of  the  hypogIo.ssal  nerve,  contain- 
ing large  nerve-cells,  h.  Nucleus  of  the  vagus  nerve,  i,  i.  Gelatinous  substauce.  k,  k.  Roots  of 
the  vagus  nerve.  I.  Roots  of  the  hypoglossal  or  ninth  nerve,  m.  A  white  bundle  of  longitudinal 
fibres  connected  with  the  root  of  the  vagus,  n.  Soft  column.  (Zartstrang,  Stilling.)  o.  Wedge-liko 
column.  (KcclKtratig,  Stilling.)  ji.  Transverse  and  arciforjn  Hbres.  q.  Nucleusof  the  olivary  bodies. 
r.  The  large  nucleus  of  the  pyramid.  «,  «,  «.  The  small  uiicloi  of  the  pyramid,  u.  A  mass  of  gray 
substance  near  the  nucleus  of  the  olives  (Oliven-Nebenkorn),  «,  ly,  r,  are  traversed  by  numerous 
fibres  passing  in  a  transverse  semicircular  direction,  v,  u;.  Arciform  fibres,    a;.  Q ray  fibres.  (4diam.) 


THE   MEDULLA   OBLONGATA   AND   PONS  VAROLII. 


461 


lie  nerves  (all  but  the  first  and  second  pairs)  rise  from  these  and 
the  crura  cerebelli.  It  is  not  consistent,  however,  with  the  object  of 
this  work  to  describe  their  complicated  structure  at  length.  A 
section  of  the  former  is  shown  by  Fig.  305. 

1.  The  white  substance  of  the  medulla  oblongata  is  in  part  continu- 
ous with  that  of  the  cord,  and  partly  distinct  from  it ;  and  everywhere 
consists  of  nerve-fibres  of  the  same  dimensions  as  those  of  the  cord. 
The  anterior  columns  of  the  cord  (Fig.  306)  are  partly  continued 
into  the  outer  part  of  the  corpora  pyramidalia ;  and  partly  ascend 
both  internally  and  externally  to  the  olivary  body,  and  proceed 
through  the  pons  Varolii  into  the  posterior  corpora  quadrigemina 
on  the  one  hand  and  the  tegmentum  of  the  crura  cerebri  on  the 
other.  The  lateral  columns  divide,  on  reaching  the  medulla,  into 
three  branches;  (1,)  ascending  mostly  into  the  crura  cerebelli,  and, 
in  small  part,  into  the  tegmentum ;  (2,)  decussating  in  two  or  three 


Yig.  306. 


Fig.  306.  Anterior  view  of  the  medulla  oblongata,  p,  p.  Corpora  pyramidalia  decussating  at  d. 
o,  o.  Olivary  bodies,  r,  r.  Restiform  bodies,  a,  a.  Arciform  fibres,  v.  Lower  fibres  of  the  pons 
Varolii. 

Fig.  307.  Posterior  view  of  the  medulla  oblongata,  p,  p.  Posterior  pyramids,  separated  by  the 
posterior  fissure,  r,  r.  Kestiform  bodies  composed  of  (c,  c)  posterior  columns,  and  (d,  d,)  lateral, 
a,  a.  Olivary  columns  as  seen  on  the  floor  of  the  fourth  ventricle,  separated  by  (*)  the  median  fis- 
sure, and  crossed  by  some  fibres  of  origin  of  (n,  n)  the  seventh  pair  of  nerves. 

fasciculi  with  that  of  the  other  side  (decussatio  pyramidum),  and 
forming  the  principal  bulk  of  the  anterior  pyramids ;  and  (3,)  ap- 
pearing between  the  posterior  columns  at  the  bottom  of  the  fourth 


•i62  THE   TISSUES. 

ventricle  as  the  posterior  pyramids,  and  being  thence  continued  on 
the  floor  of  the  ventricle,  side  by  side,  into  the  tegmentum  of  the 
crura  cerebri.  The  posierior  columrts  (Fig.  307)  in  part  constitute 
the  corpora  restiformia,  and  finally  enter  the  crura  cerebelli ;  while 
the  remainder,  situated  externally  to  the  posterior  pyramids,  also 
enters  the  tegmentum  of  the  crura  cerebri.  There  is  also  a  system  of 
horizontal  nerve-fibres  v^-hich  are  independent  of  the  cord,  and  which 
are  probably  commissural. 

2.  The  gray  rrvoMer  of  the  medulla  oblongata  is  collected  into  larger 
masses  principally  in  three  situations ;  viz.,  in  the  olivary  and  the 
restiform  bodies,  and  in  the  floor  of  the  fourth  ventricle.  1.  The 
gray  matter  of  the  olivary  body  constitutes  a  capsule,  closed  on  all 
sides  except  the  inner:  and  is  entirely  isolated  from  all  other  gray 
substance.  It  is  traversed  by  very  numerous  nerve-fibres  of  the 
horizontal  system.  2.  The  gray  matter  of  the  restiform  bodies  may  be 
regarded  as  a  continuation  of  the  posterior  horns  of  the  spinal  cord, 
and  even  presents  some  resemblance  to  their  substantia  gelatinosa. 
{Stilling.)  3.  The  gray  substance  of  the  floor  of  the  fourth  ventricle 
is  a  continuation  of  the  central  gray  matter  of  the  cord,  and  forms 
a  tolerably  thick  layer  from  the  calamus  scriptorius  to  the  aqi/e- 
dudus  Sylvii.  The  portion  in  the  anterior  half  of  this  ventricle 
belongs  properly  to  the  pons  TaroliL — Besides  these  three  masses  of 
grav  matter,  there  are  other  verv  small  ones  in  the  medulla  oblon- 
gata,  not  requiring  a  description  here.  In  no  case  are  the  nerve- 
fibres  (the  horizontal,  or  those  from  the  cord)  known  to  be  conti- 
nuous with  the  processes  of  the  nerve-cells. 

Do  the  ten  pairs  of  encephalic  nerves,  mentioned  on  page  461, 
rise  from  the  gray  matter  of  the  medulla  oblongata  to  which  they 
have  been  mostly  traced  by  StilliDg  and  others?  We  deem  it  most 
probable  that  they  rise  in  the  corpora  striata  and  optic  thalami,  for 
reasons  assigned  by  KoUiker.'  That  the  gray  matter,  however, 
inflaenees  the  nerve-fibres  which  traverse  it,  is  at  the  same  time 
most  probable. 

2.  77te  Cerebellum. 

The  gray  matter  of  the  cerebellum  occurs  only  on  the  surface  of 

the  convolutions,  in  the  nucleus  derUatus^  and  the  roof  of  the  fourth 

ventricle:  all  the  rest  being  white  substance.     The  latter  consists 

of  parallel  nerve-fibres,  presenting  all  the   characters  of  central 

'  Pp.  377-8. 


STRUCTURE  OF  THE  CEREBELLUM. 


463 


Fig.  308. 


fibres  (softness,  proneness  to  become  varicose,  easy  isolation  of  the 
axis-fibre,  &c.);  and  do  not  require  a  special  description.  They 
average  g^^^^  of  an  inch;  the  extreme  being  y^^^^  and  -srhv  of  an 
inch. 

The  graij  substance  of  the  convolutions  of  the  cerebellum  alone 
requires  a  special  description.  It  everywhere  consists  of  a  layer 
externally  gray,  and  internally  of  a  rusty  color  (ferruginous  layer). 
The  latter  contains  nerve-fibres  and  large  masses  of  free  nuclei. 
The  fibres  are  continuations  of  those  of  the  white  substance;  and 
extending  through  the  ferruginous  layer  to  the  gray  layer,  they 
break  up  into  numerous  fine  fasciculi,  so  interlaced  that  the  whole 
ferruginous  layer  is  penetrated  by  a  close  but  delicate  network  of 
fine  fibres  somewhat  resembling  the  terminal  plexus  of  the  acoustic 
nerve.  The  free  nuclei  lie  in  the  meshes  formed  by  the  nerve- 
fibres;  being  from  go'gg  to  3  (5V-0  of  an  inch  in  diameter,  and  fre- 
quently exhibiting  a  dis- 
tinct nucleolus  and  some- 
times other  granules. — 
The  nerve-fibres,  however, 
do  not  terminate  in  the 
ferruginous  layer.  Be- 
coming attenuated  mostly 
to  a  diameter  of  jo^oo  of 
an  inch,  they  enter  the  ex- 
ternal gray  layer  to  termi- 
nate in  its  inner  stratum, 
which  contains  nerve-fi- 
bres and  well-marked 
large  nerve-cells ;  while 
the  outer  portion  contains 
no  nerve-cells,  but  merely 
a  finely  granular,  pale, 
light-yellowish  substance, 
agreeing  in  all  respects 
with  the  already  described 
contents  of  the  nerve-cells. 

The  cells  generally  in 


Ganglion-cells,  with  their  processes,  nxiclei,  and  nucleoli. 
a,  a.  From  the  deeper  part  of  the  gray  matter  of  the  con- 
volutions of  the  ccrehellum.  The  larger  processes  are  di- 
rected towards  i  he  surface,  b.  Another  form  from  the  cere- 
helium,  c,  d.  Others  from  the  posterior  horn  of  gray  matter 
the  gray   matter     resemble     of  the  dorsal  region  of  the  cord.     These  contain  pigment 

which  surrounds  the  nucleus  in  (cV     In  all  these  specimens 
the  processes  are  more  or  less  broken.  (Magnified  200  dia- 

described.      Entirely  dif-    meters.) 


those  of  the  cord,  already 


464  THE   TISSUES. 

ferent,  however,  from  these  smaller  elements  are  the  large  cells  dis- 
covered by  Purkinje,  and  which  are  found  only  in  the  innermost 
j)ortions  of  the  gray,  next  to  the  ferruginous  layer.  (Fig.  808,  a.) 
These  measure  ^^-jy  to  ^^^  of  an  inch,  are  round,  pyriform,  or  oval, 
with  finely  granular  colorless  contents,  and  1  to  4  (generally  2  or 
3)  long  and  much  branched  processes;  the  largest  of  these  being 
given  off  from  the  sides  of  the  cells  which  look  from  the  ferrugin- 
ous layer,  and  extending  nearly  to  the  outer  surface  (f  or  f  of  its 
thickness),  and  producing  a  striation  seen  in  horizontal  sections. 
At  their  origin  these  processes  are  sometimes  g^'g^  of  an  inch  thick, 
and  very  finely  granular  or  delicately  striated.  As  they  proceed 
they  become  more  homogeneous,  and  divide  into  numerous  ex- 
tremely slender  branches,  the  ultimate  ones  being  scarcely  j^ohuu 
of  an  inch  thick.  Kcilliker  has  traced  these  processes  even  g'g  of 
an  inch  without  coming  to  the  finest  subdivisions.  While  tlieir 
principal  prolongations  are  thus  continued  through  the  gray  layer, 
ihey  give  off  their  branches  at  acute  or  right  angles,  producing  a 
second  striation,  crossing  the  one  before-mentioned  at  a  greater  or 
less  angle. 

T\iQ  crura  cerebelli  contain  nerve- fibres  only ;  being  a  continua- 
tion of  the  white  matter  of  the  cerebellum  itself. 

3.   The  Ganglia  of  the  Cerebrum. 

Of  these  there  are  three  pairs;  the  corpora  quadrigemina,  the 
optic  thalami,  and  the  corpora  striata.  (Fig.  309.)  All  these  are 
bulky  collections  of  gray  substance  and  nerve-fibres.  The  latter 
connect  these  ganglia  on  the  one  hand  with  the  cerebellum  and 
medulla  oblongata,  and  on  the  other  with  the  hemispheres  of  the 
cerebrum.     They  present  no  histological  peculiarities. 

Nor  is  it  necessary  particularly  to  describe  the  gray  matter  in 
these  three  ganglia.  Kcilliker  considers  it  as  made  out  that  the  fine 
nerve-fibres  traceable  to  the  outermost  part  of  the  ventricular  nu- 
cleus (the  posterior  and  inferior  portions)  of  the  corpus  striatum, 
terminate  there,  and  do  not  proceed  to  the  cerebral  hemispheres.  lie  also 
regards  it  as  probable  that  the  fibres  becoming  attenuated  in  the 
optic  thalamus  and  the  tubercula  quadrigemina,  terminate  in  like 
manner.  At  the  same  time,  it  appears  to  be  the  fact  that  nerve- 
fibres  rising  in  the  cerebral  hemispheres  also  become  attenuated 
and  terminate  in  these  same  ganglia. 

Other  parts  connected  with  these  ganglia,  and  containing  gray 


GANGLIA   OF   THE   CEREBRUM. 


465 


matter,  are — the  substantia  nigra  of  the  crus  cerebri,  the  commissura 
mollis,  the  floor  of  the  third  ventricle  immediatelj  behind  and  beneath 

Fig.  309. 


Diagram  of  the  mutual  relations  of  the  principal  encephalic  centres,  as  shown  in  a  vertical  sec- 
tion. A.  Cerebrum,  b.  Cerebellum,  c.  Sensori-motor  tract,  including  the  olfactory  ganglion  {olf), 
the  tubercula  quadrigemina,  or  optic  ganglia  {o2yt),  and  the  auditory  (and),  with  the  thalami  optici 
(thai)  and  the  corpora  striata  (es).  d.  Medulla  oblongata,  e.  Spinal  cord ;  a,  olfactory  nerve ; 
b,  optic ;  c,  auditory  ;  d,  pneumogastric ;  e,  hypoglossal ;  /,  spinal  accessory.  Fibres  of  the  medullary 
substance  of  the  cerebrum  are  shown  connecting  its  ganglionic  surface  with  the  sensori-motor  tract. 

the  anterior  commissure,  and  the  tuber  cinereum.  The  pineal  body 
contains  pale  rounded  apolar  cells  and  scattered  nerve-fibres,  and 
generally  also  a  considerable  quantity  of  sabulous  matter  (princi- 
pally carbonate  of  lime,  with  phosphate  of  lime  and  magnesia). 
^he  pituitary  body  contains  in  its  anterior  reddish  lobe  no  nervous 
elements  at  all,  but  the  "elementary  tissues  of  blood-vascular 
glands."  (Ecker.)  The  posterior  smaller  lobe  consists  of  a  fine 
granular  substance  with  nuclei  and  bloodvessels;  and  also  fine 
varicose  nerve-fibres,  which,  like  the  vessels,  descend  from  the  in- 
fundibulum. 


4.  The  Cerebral  Semispheres, 
The  white  substance  of  the  hemispheres  of  the  brain  consists  en- 
tirely of  nerve-fibres,  j^^^o  ^^  -^-q^^  of  an  inch  (average  g^j'^^  of 
an  inch)  in  diameter.     These  never  form  plexiform  interlacements 
30 


466 


THE   TISSUES. 


or  fasciculi,  but  all  run  in  parallel  and  generally  straight  lines,  and 
certainly  proceed  from  the  ganglia  of  the  cerebrum  and  the  corpus 
callosum  to  the  gray  substance  of  the  central  convolutions.  There 
are  also  other  fibres  crossing  the  former  at  right  angles  (commis- 
sural fibres),  of  whose  origin  nothing  satisfactory  is  yet  known. 

The  gray  matter  of  the  cerebrum  is  principally  situated  externally, 
covering  the  convolutions,  and  being  ^  to  ^  of  an  inch  thick.  It 
contains  in  its  whole  thickness  both  nerve-cells  and  nerve-fibres; 
besides  a  large  amount  of  granular  homogeneous  substance  pre- 
cisely like  that  of  the  cerebellum.  It  is,  however,  conveniently 
divided  into  three  layers ;  1,  an  internal  yellowish-red ;  2,  a  middle, 
pure  gray;  and  3,  an  external,  white.    The  first  mentioned,  however, 

Fig.  310. 


Kervo-cells  from  the  internal  portions  of  the  gray  layer  of  the  convolutions  of  the  human  cere- 
brum, a.  Larger,  b.  Smaller,  c.  Nerve-fibro  with  axis-cylinder. — Magnified  S.OO  diameters.  (KCl- 
Itker.) 

constituting  almost  one-half  the  entire  thickness  of  the  gray  mat- 
ter, may  itself  be  divided  into  four  layers;  1,  a  yellowish-red  layer 
(inner  part);  2,  the  inner  white  streak;  3,  yellowish-red  layer  (outer 
part) ;  4,  outer  white  streak.  Tlien  come  the  two  remaining  layers 
above ;  5,  the  pure  gray,  and  6,  the  white  The  nerve-cells  through- 
out the  gray  matter  have  from  1  to  6  processes  giving  off  numerous 
branches,  ultimately  becoming  very  fine  pale  fibrils  of  ^^  J^g  of  an 


THE   CEREBRAL   HEMISPHERES. 


467 


inch.  In  the  external  white  layer  the  cells  are  few  and  small,  with 
one  or  two  processes,  and  scattered  in  an  abundant  finely  granular 
matrix.  The  pure  gray  layer  most  abounds  in  cells,  and  which 
are  also  closely  aggregated  in  a  granular  matrix.  Some  of  them 
are  very  small  {^j^^-q  to  j^'^^  of  an  inch),  appearing  frequently  as 
scarcely  more  than  nuclei ;  while  there  are  others  larger,  even  to 
g^^  of  an  inch.  (Fig,  310.)  Most  of  them  have  from  1  to  6  pro- 
cesses (usually  3,  4,  or  5).  Finally,  in  the  innermost  yellowish-red 
layer,  the  cells  are  less,  though  still  very  abundant,  and  present  the 
same  characters  as  those  of  the  gray  substance. 

The  nerve-fibres  of  the  gray  substance  of  the  convolutions,  come 
from  the  white  substance  of  the  hemispheres,  and  penetrate  the 
yellowish-red  layer  in  all  directions,  but  more  especially  parallel  to 

Fig.  311. 


Finest  nerve-tubes  of  the  superficial  white  substance  of  the  human  cerebrum. 

meters.     (Ki'lliker.) 


-Maguiflcd   ViO  dia- 


the  surface;  and  consequently  they  cross  the  main  fasciculi.  It  is 
these  horizontal  fibres  which  produce  the  white  streaks  before  men- 
tioned; and  it  is  in  the  external  white  streak  that  tlie  fasciculi  enter- 
ing the  gray  substance  are  lost.  The  fibres,  however,  which  do 
not  take  a  horizontal  direction,  proceed  onwards  even  through  the 
pure  gray  layer,  and  into  the  external  white  layer.  Ilere  they 
take  a  horizontal  direction,  and  form  several  superimposed  layers 


4(38  THE   TISSUES. 

of  the  finest  fibres  crossing  each  other  in  various  directions.  (Fig. 
811.)  Many  of  these  fibres  also  form  /oops,  and  return  into  the 
gray-red  substance,  again,  as  first  shown  by  Valentin  (p.  448). 

Kcilliker  has  not  been  able  to  discover  any  connection  between 
these  fibres  and  the  cells  of  the  gray  matter  of  the  convolutions ; 
though  the  existence  of  such  a  connection  is  nowhere  else  so  pro- 
bable as  here.  Doubtless  the  nerve-fibres  originate  here,  if  any- 
where in  the  central  organs.  Professor  Domrich  has,  however, 
traced  the  many -rayed  cells  of  the  cerebellum  into  nerve-fibres,  as 
he  asserts ;  and  Kcilliker  has  found  divisions  of  the  nerve-fibres  in 
the  cord,  but  never  in  the  encephalon.  It  is  probable  that  the 
fibres  of  the  corpus  callosum  and  the  commissural  fibres  in  general, 
commence  in  cells  in  one  hemisphere  and  terminate  in  the  other. 

Gray  matter  is  also  found  in  the  cerebrum  at  other  points ;  viz., 
in  the  anterior  portions  of  the  body  of  the  corpus  callosuvi,  above 
the  septum  lucidum,  the  fornix,  and  the  corpus  striatum;  occasion- 
ally on  the  surface  of  the  corpus  callosum  between  the  raphe  and 
the  strio3,  and  which  is  continued  into  the  fascia  dentata  of  the  pes 
hippocampi,  and  in  the  hippocampus  itself. 

The  Membranes  and  Vessels  of  the  Nervous  Centres. 

The  whole  cerebro-spinal  axis,  just  described,  is  inclosed  in  three 
membranes;  1,  the  internal,  or  pia  mater ;  2,  the  middle,  or  arach- 
noid; and  3,  the  external,  the  dura  mater. 

1.  The  7)ia  mater  is  the  vascular  membrane  of  the  nervous  cen- 
tres. It  is  composed  of  collagenous  tissue  (p.  279,  6),  and  conducts 
the  vessels  into  the  nervous  substance.  Hence  it  is  in  intimate 
contact  everywhere  with  the  cord,  and  covers  all  the  elevations  and 
depressions  on  the  surface  of  the  encephalon ;  excepting  alone  the 
floor  of  the  fourth  ventricle,  above  which  it  stretches  across.  On 
the  cerebrum  it  is  more  vascular  and  more  delicate  than  upon  the 
cord.  It  penetrates  into  the  brain  only  at  one  point,  viz.,  the  trans- 
verse fissure  of  the  cerebrum — where,  under  the  name  of  the  velum 
interpositum  it  invests  the  vena  magna  Galeni  and  the  pineal  body  ; 
then  forms  the  tela  choroidea  superior^  the  clioroid plexus  of  the  third 
ventricle,  and  the  vascular  plexuses  of  the  lateral  ventricles^  which  are 
continuous  with  the  pia  mater  at  the  base  of  the  brain.  It  con- 
tains fusiform,  bright-yellow,  or  brov/n  pigment-cells,  both  in  its 
spinal  and  its  encephalic  portions.  They  arc  so  abundant  in  the 
cervical  region  as  not  unfre(piently  to  give  the  membrane  a  brown 


MEMBKANES   OF   THE   NERVOUS   CENTRES. 


469 


or  even  blackish  color.     They  are  also  found  in  the  medulla  ob- 
longata and  the  pons  Varolii,  and  still  more  anteriorly. 

The  vascular  plexuses,  just  named,  in  the  ventricles  are  composed 
mostly  of  vessels,  and  are  covered  by  an  epithelium  where  they 
are  not  adherent  to  the  walls  of  the  ventricles.  This  consists  of  a 
single  layer  of  roundish  polygonal  cells,  y^'g^  to  tAtt  of  ^^  i"ch 
in  diameter,  and  ^^^Vct  to  auVu  of  an  inch  thick;  containing,  besides 
the  rounded  nucleus,  many  yellowish  granules,  and  one  or  two  dark 
round  oil-drops  measuring  jsotjo  ^o  jsjih-u  of  an  inch.  It  is  not 
probable  that  they  are  ciliated,  as  asserted  by  Valentin.  Under- 
neath the  epithelium  is  a  simple  membrane ;  and  next,  the  vessels 
connected  by  a  hyaline  homogeneous 
substance  (p.  108). 

All  the  portions  of  the  ventricles 
not  covered  by  the  continuations  of 
the  pia  mater,  have  a  special  lining 
membrane,  the  ependyma  ventrictdo- 
rum.  This  is  a  simple  conoidal  epi- 
thelium (Fig.  312);  and  it  is  separated 
from  the  brain-substance  by  a  fila- 
mentous layer  Ts^au  to  ^\-q  of  an  inch 
thick,  of  embryonic  areolar  tissue. 
Virchow  and  Kolliker  did  not  find  it 
to  exhibit  ciliary  motion,  as  asserted 


Fig.  312. 


J>§ 


The  ependyma  in  man.  A.  From  the 
corpus  striatum  ;  1,  from  the  surface  ;  2, 
from  the  side ;  a,  epithelial  cells  ;  6, 
nerve-fibres  lying  beneath,  b.  Epithe- 
lium-cells from  the  commissura  mollis. — 
Magnified  350  diameters.     {Kolliker. ) 


by  Purkinje  and  Valentin. 

2.  The  arachnoid  membrane  does  not  consist  of  two  lamelliB,  as 
usually  described ;  but  of  a  single  one,  the  internal  one  of  authors. 
This  is  an  extremely  delicate  transparent  membrane,  corresponding 
in  extent  to  the  dura  mater.  It  is  made  up  of  lamellas  of  fasciculi 
of  white  fibrous  tissue,  surrounded  by  fine  elastic  fibres.  In  the 
spinal  canal  it  is  loosely  adherent  to  the  pia  mater,  by  fasciculi  of 
areolar  tissue,  so  that  a  space,  called  the  subarachnoid  sjMce,  exists 
between  it  and  the  latter  membrane,  and  which  is  filled  with  the 
cerebro-spinal  fluid.  In  the  cranium  it  is  much  more  adherent  to 
the  pia  mater.  Thus,  there  is  no  continuous  subarachnoid  space 
upon  the  brain,  but  numerous  larger  and  smaller  spaces  only  par- 
tially communicating.  The  larger  of  these  spaces  (between  the 
cerebellum  and  medulla  oblongata,  under  the  pons  Varolii,  the 
crura  cerebri,  and  the  fossa  Sylvii),  open  directly  into  the  subarach- 
noid space  of  the  spinal  cord;  while  the  remaining  ones  do  not. 


470  THE   TISSUES. 

The  arachnoid  has  no  connection  with  the  lining  membrane  of  the 
ventricles.  Finally,  the  free  surface  of  the  arachnoid  is  covered  by 
a  simple  scaly  epithelium.  The  external  lamina,  so  called,  of  the 
arachnoid,  is  merely  a  precisely  similar  epithelium  upon  the  dura 
mater. 

3.  The  dura  mater  of  the  cord  (theca  vertebralis),  is  a  v^'hitish- 
yellow,  sometimes  glistening,  firm,  and  somewhat  elastic  membrane, 
formed  of  parallel  fasciculi  of  white  fibrous  tissue,  and  of  a  fine 
elastic  fibrous  network  in  almost  equal  proportions.  It  is  twice  as 
thick  posteriorly  as  anteriorly ;  and  in  the  latter  position  is  pretty 
firmly  united  to  the  anterior  common  vertebral  ligament,  while  it 
is  free  on  the  sides  and  behind.  Internally,  the  dura  mater  is  co- 
vered by  a  simple  scaly  epithelium  alone,  there  being  no  external 
lamella  of  the  arachnoid.  The  ligamentum  derdiculatum.  has  no 
epithelium,  and  presents  a  structure  precisely  like  that  of  the  dura 
mater. 

In  the  cranium,  the  dura  mater  is  thicker  and  whiter  than  in  the 
spinal  canal,  and  consists  of  two  layers:  1,  the  external  or  perios- 
teal, and  2,  the  internal.  The  former,  more  laxly  united  to  the 
latter  at  an  early  period,  is  whitish-yellow  and  rough,  and  attached 
more  or  less  firmly  to  the  bones,  and  supports  the  larger  meningeal 
vessels.  The  internal  layer,  or  proper  dura  mater,  is  less  vascular, 
whiter,  has  generally  a  glistening  tendinous  aspect,  and  its  surface 
is  quite  smooth.  Between  the  two  layers,  with  few  exceptions,  the 
sinuses  are  situated.  The  processes  of  the  dura  mater  (the  falx 
cerebri  and  cerebelli,  and  the  tentorium)  are  prolongations  of  the 
internal  layer.  The  simple  scaly  epithelium  covering  the  dura 
mater  consists  of  cells  of  24VTJ  to  50V0  of  ^.n  inch,  with  rounded  or 
elongated  nuclei  g^xr  ^o  4  At7  of  an  inch  in  diameter. 

Vessels  and  Nerves  of  the  preceding  Membranes. — The  dura  m^ater 
of  the  cord  has  in  its  substance  but  few  vessels,  though  numerous 
arteries  and  veins  of  the  cord  perforate  it.  The  dura  mator  of  the 
encephalon  is  far  more  vascular,  as  already  described,  especially  in 
its  external  or  periosteal  layer.  The  sinuses  in  it  are  simple  exca- 
vations lined  with  an  epithelium. 

The  arachnoid  membrane,  whether  of  the  brain  or  the  spinal 
cord,  contains  no  proper  vessels. 

The  pia  mater  both  of  the  brain  and  the  cord,  has  a  tolerably 
rich  capillary  plexus  of  its  own,  besides  supporting  the  very  co- 
pious ramifications  of  the  vessels  of  the  nervous  substance. 


VESSELS   AND  NERVES   OF   CEREBRAL    MEMBRANES.      471 

Lymphatics  arc  so.id  to  have  been  demonstrated  bj  Fohmann  and 
Arnold  in  the  pia  mater,  on  the  surface  both  of  the  cerebrum  and 
cerebellum,  and  in  the  choroid  plexus — an  observation  needing 
confirmation. 

Nerves  also  are  found  in  the  membranes  of  the  nervous  centres. 
The  dura  mater  of  the  cerebrum  has  nerves  (twigs  of  the  eighth 
pair),  pretty  nearly  following  the  course  of  tlie  meningeal  arteries, 
and  especially  upon  the  middle  meningeal.  A  twig  from  the  third 
branch  of  the  fifth  pair  is  distributed  principally  to  the  bones. 
Another  from  the  fifth  pair  is  called  the  nerve  of  the  tentorium 
cerebelli,  and  goes  to  the  larger  sinuses  of  the  dura  mater.  {Pappen- 
heim.)  Neither  Kolliker  nor  Purkinje  has  detected  any  nerves  in 
the  theca  vertebralis ;  though  they  occur  in  the  periosteum  of  the 
vertebral  canal,  and  on  the  arteries  going  to  the  vertebras  and  the 
cord. 

The  arachnoid  contains  no  proper  nerves,  but  the  vessels  pene- 
trating it  do,  especially  at  the  base  of  the  brain.     The  p?a  mater  of 


Fig.  313. 


Fig.  314. 


Fig.  313.  Vessels  of  the  cerebral  substance  of  the  sheep,  from  one  of  Gerlach's  injections;  a,  of 
the  gray;  b,  of  the  white  substance.     (KVUiker.) 

Fig.  314.  Two  terminal  arteries  from  a  branch  on  the  surface  of  a  convolution  of  the  cerebrum, 
and  dipping  vertically  inwards ;  and  exhibiting  the  mode  of  origin  and  distribution  of  capillaries  in 
the  gray  cortical  layer.     From  an  injected  specimen.     (Maguificd  30  diameters.) 


472 


THE    TISSUES. 


the  cord  is  richly  supplied  with  plexuses  of  fine  nerve-fibres  which 
accompany  the  vessels.  At  the  base  of  the  brain,  many  similar 
plexuses  occur  on  the  arteries  of  the  circle  of  Willis,  which  are 
distributed  in  twigs  ^^^  of  an  inch  in  diameter  through  the  entire 
cerebral  pia  mater,  following  its  vessels,  but  not  those  of  the  cere- 
bellum. 

The  vessels  of  the  cord  and  encephalon  themselves  on  leaving  the 
pia  mater,  are  supplied  to  the  gray  matter  much  more  abundantly 
than  to  the  white  substance ;  the  capillary  plexus  being  closer  (and 
the  capillaries  themselves  of  less  calibre),  to  which  the  dark  color  is 
in  part  due.  The  interstices  of  the  capillaries  in  the  white  sub- 
stance are  g^^  by  g^o  of  an  inch.  {E.  TFeier.)  In  the  sheep's  brain 
the  breadth  of  the  interstices  of  the  gray  substance  is  three  or  four 
times  less  than  in  the  white.  {Gerlach)  (Fig.  313.)  The  finest 
capillaries  in  the  cord  measure  54^54  of  an  inch,  and  in  the  brain, 
g/o  0  of  an  inch.  The  manner  in  which  the  terminal  arteries  merge 
into  the  capillaries  on  entering  the  gray  matter  of  the  convolutions 
from  the  pia  mater  is  shown  by  Fig.  314. 

Chemical  Composition  of  the  Nervous  Centres. 

The  composition  of  the  elements  of  the  nerve-fibres  has  already 
been  given,  so  far  as  it  is  understood  (p.  430).  The  composition  of 
the  white  and  gray  matter  of  the  encephalon  will  now  be  specified. 

Vauquelin  states  that  the  spinal  cord  and  medulla  oblongata  have 
the  same  composition  as  the  cerebrum,  except  that  they  contain 
much  more  fat,  with  less  albumen,  ozmazome,  and  water.  The  ana- 
lyses of  the  encephalon  alone  will  be  here  given;  and  those  of  Von 
Bibra  will  be  adopted  as  the  most  recent  and  reliable.' 

The  following  is  Von  Bibra's  analysis  of  the  gray  and  the  white 
matter,  separately,  of  the  brain  of  a  man  aged  30  years,  who  died 
of  phthisis: — 


Gray  substance 

of  cerebral  ho- 

niisplusres. 

Wliito  substance 

of  corpus  callo- 

Kum. 

White  substance 
of  medulla  ob- 
longata. 

Water 

Fat 

Solids,  exclusive  of  fat          ... 

83.57 

(5.43 

10.00 

69.19 
20.43 
10.38 

71.55 
14.67 
13.78 

'  Comparative  Investigations  of  the  Brain  of  Man  and  tlie  Mammalia, 
heim,  1854. 


Mann- 


CHEMICAL   COMPOSITION   OF   NEKVOUS   CENTKES.      473 


The  following  is  his  analysis  of  the  entire  enccphalon  of  the 
foetus  at  different  stages,  and  that  of  a  child  at  6  months : — 


Water 

Fat     .... 

Solids,  exclusive  of  fat 


85.10 

1.26 

13.64 


86.71 

0.99 

12.30 


At  10        At  12    1    At  14        At  18    I    At  20    I    At  21        At  37    i  Child  6 
wooks.  I  weeks,     weeks,     weeks.  I  weeks,     weeks,     weeks.  Imonths. 


86.24 

1.53 

12.23 


86.90  I  86.03  |  85.93    87.90 

1.06      1.07      1.23      3.06 

12.04  i  12.60    12.84      9.04 


82.96 

6.99 

10.04 


Thus  the  gray  substance  contains  more  ivater  than  the  white,  the 
water  being  replaced  in  the  latter  by  fat.  The  water  in  the  brain 
of  the  foetus  is  also  far  more  abundant  than  in  the  adult,  the  differ- 
ence being  made  up  by  an  increase  of  fat  in  the  latter.  The  sudden 
increase  of  fat  for  a  short  time  before  and  after  birth,  is  a  fact  of 
much  physiological  interest. 

The  quantity  oi  fat  in  the  brain  is  found  to  be  constant,  within 
certain  limits.  It  is  not  diminished  in  diseases  occasioning  ema- 
ciation in  other  parts,  nor  is  it  increased  in  the  lower  animals  by 
fattening.  It  seems  to  be  established  that  the  fat  has  important 
relations  to  the  functions  of  the  brain.  Its  amount  is  a  little  less 
in  old  men  than  in  adults  in  the  prime  of  life.  L'Heritier's  analyses 
also  show  that  it  increases  from  infancy  up  to  adult  age. 

In  man,  other  mammalia,  and  birds,  the  medulla  oblongata  con- 
tains more  fat  than  the  cerebellum  and  the  cerebrum.  There  is  the 
most  fat,  relatively  and  absolutely,  in  the  hemispheres  of  the  human 
brain ;  next  in  other  mammals,  and  then  in  birds,  amphibians,  and 
fishes. 

An  analysis  of  the  brain-fat  shows  it  to  consist  of  cerebric  acid 
20  to  21  per  cent.,  cholesterine  80  to  33  per  cent.,  and  a  series  of 
fatty  acids  constantly  varying  in  composition,  and  which  contain 
no  nitrogen  or  sulphur.  The  white  substance  contains  more  cere- 
bric acid  and  cholesterine  than  the  gray,  and  consequently  less  of 
the  other  fats.  The  quantity  of  cerebric  acid  seems  to  diminish  as 
we  descend  the  animal  scale,  and  is  less  in  the  foetus  and  the  infant 
than  in  the  adult. 

Phosphorus  is  also  contained  in  the  brain-fat ;  except  the  fatty 
acids,  which  solidify  at  a  temperature  below  38|-°  (Fahr.).  In  a 
man  who  died  at  59  years  of  age,  of  Bright's  disease,  the  phospho- 
rus in  the  whole  brain  amounted  to  1.68  per  cent,  of  the  fat.  There 
was  the  most  in  the  hemispheres,  the  cerebellum,  and  pons  Varolii 
(1.83  per  cent.) ;  and  the  least  (1.5-4  per  cent.)  in  the  optic  thalami 


474  THE   TISSUES. 

and  corpus  callosum.  Von  Bibra  concludes  that  the  amount  of 
phosphorus  in  brain-fat  is  very  nearly  the  same  in  man,  other  mam- 
mals, and  birds;  that  its  amount  is  not  essentially  modified  in  in- 
sanity, in  old  age,  in  very  young  persons,  and  even  in  the  embryo ; 
and  that  there  is  no  reason  to  believe  that  the  intelligence  is  espe- 
cially connected  with  its  amount.  The  fat  of  the  gray  matter  of 
the  brain,  however,  contains  rather  more  phosphorus  than  that  of 
the  white  matter. 

The  other  solids,  besides  fat,  alluded  to,  are  albumen,  another  albu- 
minoid substance  not  coagulable  by  boiling,  and  the  mineral  sub- 
stances usually  met  with  in  other  organs  and  in  the  formative  fluids. 
Sulphates  are,  however,  almost  entirely  absent,  and  the  chlorine 
varies  much  in  amount.  Of  the  earthy  phosphates,  the  medulla 
oblongata  contains  a  larger  proportion  than  other  parts  of  the  en- 
cephalon.  They  are  also  more  abundant  in  the  brain  of  amphibians 
and  fishes  than  in  the  higher  animals.  In  fact,  all  the  inorganic 
constituents  are  least  abundant  in  the  brain  of  man  and  other  mam- 
mals, greater  in  birds,  and  greatest  in  amphibians  and  fishes.  The 
ratio  of  the  potash  to  the  soda  in  the  human  brain  is  nearly  inter- 
mediate between  the  ratios  occurring  in  the  ashes  of  flesh  and  blood 
respectively  (p.  395). 

Functions  of  the  Nervous  System. 

For  definite  information  on  this  subject,  reference  must  be  had 
to  the  treatises  on  physiology.  It  may  here  only  be  remarked  that, 
so  far  as  motion  is  concerned,  the  gray  matter  of  the  spinal  cord  is 
probably  the  centre  of  reflex  (or  diastaltic)  motion;  the  ganglia  of 
the  cerebrum  are  the  centre  of  the  emotional  (and  sensational) 
actions;  and  the  cerebral  hemispheres  are  the  source  of  voluntary 
motion.  On  the  other  hand,  some  part  of  the  cerebrum  (and,  most 
probably,  the  optic  thalami)  is  the  centre  of  sensation;  while  the 
sympathetic  influences  ascribed  to  the  ganglionic  nervous  system 
are  not  peculiar  to  it,  but  inhere  also  in  the  ganglionic  nerve-fibres 
in  the  spinal  nerves;  these  fibres  also  being  the  probable  channel 
through  which  emotions  affect  the  organic  functions,  and  especially 
that  of  secretion — as  of  the  milk,  the  lachrymal  fluid,  &c. 

The  cerebral  hemispheres  are  also  the  centre  of  the  intellectual 
and  moral  faculties;  while  the  cerebellum  presides  over  the  co- 
ordination of  the  voluntary  motions,  but  takes  no  part  in  the  mental 
phenomena.    Certain  facts  point  to  the  conclusion  that  it  is  also  the 


THE   MEMBRANES.  475 

seat  oftlie  sexual  impulse;  but  this  function  cannot  yet  be  regarded 
as  established. 

Pathological  States  of  the  Nervous  Centres. 

Certain  pathological  conditions  of  the  nerve-fibres  and  the  nerve- 
cells  have  already  been  specified  (pp.  433  and  437).  The  encephalon 
and  cord  are  also  afiected  by  softening  and  various  other  abnormal 
states — as  from  the  development  of  tumors,  &c.  'But  the  consequent 
lesions  of  motion,  sensation,  and  the  intellectual  faculties,  are  too 
numerous  and  complicated  to  be  described  here. 


CHAPTBE    XI. 

THE    MEMBRANES. 


The  synovial  membranes  (p.  344),  the  vaginal  sheaths,  and  the 
bursas  mucosae  (p.  418,  3),  have  already  been  described.  Those  to 
be  described  in  this  chapter  are: — 

1.  The  cutaneous  membrane,  or  skin. 

2.  The  mucous  membranes. 

3.  The  serous  membranes. 

Each  of  these  consists  of  the  same  histological  elements  from 
within  outwards;  viz.,  1,  thecorium;  2,  the  basement-membrane ; 
and  3,  the  epithelium.  Thus  no  tissues,  not  already  described, 
occur  in  them. 

Both  the  skin  and  the  mucous  membranes  present  elevations  and 

Fig.  315. 


Typical  forms  of  papill£e  of  the  skin  and  mucous  membrane,  and  intestinal  villi,  a.  Basement- 
membrano.  b.  Epithelial  layer  of  secreting  colls,  mostly  detached,  c.  Layerof  capillary  vessels  in 
the  cerium  of  the  sliin  or  mucous  membrane,  d.  Simple  papilla  or  villus,  e,  f.  Compound  (branched) 
papilhc. 

depressions  on  their  surflice;  the  former  being  termed  papillte  and 
villi,  and  the  latter,  glands.  Fig.  315  represents  the  forms  of  the 
papillce,  and  Fig.  316  of  the  glands. 


476 


THE   TISSUES. 


I.  The  Skin. 

1,  The  corium  of  the  skin,  or  innermost  layer,  constitutes  the 
greater  part  of  its  entire  thickness  in  most  parts  of  the  body ;  and 

this   alone    is   converted 
^'S-316.  jj^^Q    leather    when    the 

skins  of  the  lower  ani- 
mals are  tanned.  Its  re- 
lation to  the  basement- 
membrane  and  the  epi- 
thelium is  shown  in  a 
vertical  section  of  the 
skin  (Fig.  317);  which 
also  shows  a  sweat  gland 
in  the  subcutaneous  areo- 
lar tissue,  or  superficial 
fascia,  described  on  page 
290.  It  is  a  tough,  slight- 
ly elastic  membrane,  com- 
posed of  white  and  yellow 
fibrous  (areolar)  tissue ;  to 
which  must  also  be  added 
smooth  muscular  fibres, 
bloodvessels,  nerves,  and 
lymphatics,  in  great  abun- 
dance. In  the  inner  por- 
tions of  the  corium,  the 
fibres  are  interwoven  in  a 
manner  to  give  indica- 
tions of  lamination.  The 
elastic  fibres  abound  in 
the  corium;  but  much 
more  in  the  subcutane- 
ous areolar  tissue.  The 
smooth  muscular  hhres  also 
abound  in  some  portions 
of  the  latter,  constituting 
the  dartos,  so  called,  under  the  skin  of  the  scrotum;  and  a  similar 
layer  under  the  skin  of  the  prepuce,  of  the  perineum,  and  the  ante- 


Typical  forms  of  glauds.  a.  ,Simjjle  glands  ;  a,  b,  e,  as  iu 
the  last  figure;  f/,  follicle  or  follicular  gland;  h,  sacculus, 
or  saccular  gland  ;  t,  tubular  gland,  the  tube  coiled  up.  b. 
Simple  racemose  glands  ;  k,  of  tubular,  and  I  of  saccular 
form.  c.  Compound  racemose  glands;  m,  entire  gland; 
showing  branched  duct  and  lobular  structure  ;  n',  a  lobule 
detached,  with  o,  branch  of  duct  proceeding  from  it.  D. 
Compound  tubular  gland. 


THE   SKIN. 


477 


rior  part  of  tlie  body  of  the  penis.  They  also  exist  under  the  skin 
of  the  areola  around  the  nipple  of  the  female,  forming  circular 
bundles  of  a  yellowish-red  color,  even  ./q  of  an  inch  thick,  and 
extending  both  circularly  and  perpendicu- 
larly into  the  nipple  itself.  But  smooth 
muscular  fibres  are  also  found  in  the  su- 
perficial  portions  of  the  corium,  and,  in 
fact,  in  every  part  where  hairs  occur  [ar- 
rectores  pili,  Eylandt^)  forming  flat  bundles 
TiVi)  to  7750  of  an  inch  broad,  which  are 
placed  singly  or  in  pairs  near  the  upper 
part  of  the  hair-follicles  and  sebaceous  fol- 
licles. Eylandt  finds  the  bundles  to  be 
only  goVo  of  an  inch  thick,  and  has  never 
seen  more  than  one  pass  to  a  hair-follicle. 
Henle  makes  them  3  oVo  of  an  inch  thick. 
Rising  from  the  superficial  part  of  the  co- 
rium, they  extend  obliquely  outwards,  and 
are  inserted  into  the  hair-follicles  close 
behind,  and  near  the  base  of  the  sebaceous 
glands  (p.  267  and  Fig.  135). 

The  inner  surface  of  the  corium  is  rough 
and  areolated,  to  correspond  with  the 
outer  surface  of  the  superficial  fascia  into 
which  it  merges.  Its  external  surface  is 
also  very  far  from  being  level,  from  the 
development  here  of  the  tactile  papillce. 
The  reddish-gray,  external,  superficial  por- 
tion of  the  corium,  containing  the  upper 
portion  of  the  hair-follicles  and  cutaneous 
glands,  and  the  terminal  expansions  of  the 
vessels  and  nerves  of  the  skin,  is  some- 
times called  the  papillary  portion  of  the 
corium.  The  tactile  jia^n'Zfe,  its  most  im- 
portant element  (Fig.  318),  are  small,  se- 
mi-transparent, flexible,  but  tolerably  solid 
elevations  of  the  external  surface  of  the 
corium,  usually  of  a  conical  or  clavate 
form,  but  sometimes  presenting  numerous 


Vertical  section  of  the  skin  of 
sole.  a.  Cuticle  ;  the  deep  layers 
(stratum  Jlalpighiannm)  more  co- 
lored than  the  upper,  and  their 
particles  rouudod  ;  the  superficial 
layers  more  and  more  scaly.  I. 
Papillary  portion.  c.  Principal 
portion  of  corium.  d.  Sweat-gland 
lying  in  a  cavity  on  the  deep  sur- 
face of  the  skin,  and  imbedded  in 
globules  of  fat.  Its  duct  is  seen 
passing  to  the  surface.  ^Magnified 
10  diameters.) 


478 


THE   TISSUES. 


points  (Qorapound  papilloe,  Fig.  319).     They  are  very  numerous  on 
the  palm  of  the  hand  and  the  sole  of  the  foot,  and  are  situated  upon 


Fig.  318. 


Fig.  318.  Papillas  of  the  palm,  the  cuticle  being  detached.     (Magnified  35  diameter.s.) 

Fig.  319.  Compound  papillse  of  the  surface  of  the  hand  with  two,  three,  and  four  subdivisions. 

a.  Base  of  a  papilla,     b,  h.  Their  separate  processes,     c,  c.  Processes  of  papilla;  whose  base  is  not 

visible. — Magnified  60  diameters.     (Ki'lliker.) 

ridges  visible  to  the  naked  eye.  E.  H.  Weber  found  upon  the  vola 
manus,  on  a  surface  1  line  square,  81  compound,  or  150  to  200 
smaller  papillae,  disposed  with  tolerable  regularity  in  two  principal 
series,  each  having  two  to  five  papilloe  in  the  transverse  direction ; 
placed  on  linear  elevations  yio  to  3^  of  an  inch  broad  by  ji^  to  ^y^j 
of  an  inch  high — the  ridges  of  the  corium. 

Elsewhere,  the  papillae  are  more  irregularly  scattered,  either  very 
closely  together,  as  in  the  labia  minora,  the  clitoris,  the  penis,  and 
the  nipple,  or  somewhat  more  widely  apart,  as  on  the  extremities 
(except  the  places  above  named),  on  the  scrotum,  the  neck,  chest, 
abdomen,  and  back. 

The  size  of  the  papillne  varies  mucb.  The  shortest  {^^^  to  ^l^ 
of  an  inch),  occur  on  the  face  ;  and  next  (ggcy  to  T^io  of  an  inch),  on 
the  female  breast,  the  scrotum,  and  at  the  root  of  the  penis.  In 
most  other  situations,  they  are  254  to  3^ g  of  an  inch  long.  The 
longest  4ggo  to  25^  of  an  inch),  are  found  on  the  palm  of  the  hand, 
the  sole  of  the  foot,  the  nipple  (where  they  are  generally  of  the 
compound  kind),  the  anterior  and  posterior  extremities  of  the  bed 
of  the  nail  (xeg  to  t2it  of  ''^n  inch),  and  the  labia  minora  (^i^  to 
y^5  of  an  inch).  The  diameter  of  the  papillae  at  the  base  gene- 
rally equals,  or  is  somewhat  less  than  the  length.  In  the  shortest, 
above-mentioned,  it  exceeds  the  length  by  ^  or  more;  and  hence 
they  resemble  warts  or  even  short  ridges.  In  the  largest  papillae 
the  breadth  is  J  to  J  the  length. 

The  distribution  of  the  bloodvessels  and  nerves  in  the  papillae 
will  be  described  on  page  488. 


THE   SKIN. 


479 


Fi-.  320. 


Finally,  tlic  thiclcness  of  tlio  coriuin  varies  from  g'g  to  ^  of  an  inch, 
being  ^'^  to  I'g  of  an  inch  in  most  places.  It  is  thinnest  (^'g  to  g"^ 
of  an  inch)  in  the  meatus  auditorius  externiis^  the  eyelids,  the  red 
border  of  the  lip,  and  the  glans  penis  and  clitoridis ;  and  thickest 
(a'j  to  t'j  of  an  inch)  on  the  back,  chin,  upper  and  lower  lip,  the 
aloe,  nasi,  the  ball  of  the  sole,  the  extremity  of  the  great  toe,  over 
the  scapula  and  the  nates,  and  on  the  heel  (even  ^^^  ^o  i  of  ^^ 
inch). 

2.  The  basement-membrane  of  the  skin  has  been  demonstrated 
only  in  certain  parts ;  and  by  Kolliker  it  is  not  recognized  as  one 
of  its  histological  elements  in  the  adult;  though  he  admits  it  exists 
in  the  embryo.     It  is  merely  a  layer  of 

simple  membrane  accurately  covering 
every  part  of  the  external  surface  of  the 
corium,  and  supportmg  the  epithelium. 

3.  The  ejjithelium  of  the  skin  has  al- 
ready been  in  a  general  way  described; 
it  being  a  compound  scaly  epithelium 
(p.  240).  Its  outer  layer,  including  the 
harder  portion  removable  by  a  blister, 
is  usually  termed  the  epidermis,  or  cu- 
ticle, or  horny  layer;  and  the  remaining 
internal  portion,  the  stratum,  Malpighii, 
or  rete  mucosum.  The  latter  consists  of 
several  layers  of  cells,  the  innermost 
being  -g^^Vo  to  o-y^o  o  ^^  ^^^  i^^^  ^ong,  and 

nnn   to  Tn'nn   of  au  luch  broad,   and 


50  0  0 


placed  perpendicularly  to  the  surface  of 
the  corium.     Sometimes  several  layers 

of  perpendicularly  arranged  cells  occur,      outer  layer  of  the  corium  ;  treated  with 

.     .  ,        ,   ■  .  „    ,  acetic  acid.    a.  Horny  layer  of  the  epi- 

glVmg  the  deepest  portion  Ot  the  stratum     dermis.     6.  The  Jlalpighian  layer,    c. 

Malpighii  a  striated  appearance.     Upon    ^°"""-    '^-  ^'"^'"^  i^'^p"^''- 

these,    several   layers   of  elongated   or 

round  cells  follow.   (Figs.  146  and  320.) 

The  cells  in  the  outermost  layer  become 

flattened,  and  thus  merge  into  those  of 

the  cuticle  or  horny  layer.  The  contents 

of  these  cells  are  never  quite  fluid,  but  are  finely  granulated,  the 

granules  invariably  diminishing  in  the  more  external  cells.     In  the 

negro  these  granules  are  colored,  as  has  been  shown  by  Fig.  68; 


Vertical  section  of  the   skin   of  the 
thumb,   showing    the    epidermis    and 


e.  Com- 
pound papilla.  /.  Epithelium  of  the 
perspiratory  duct,  continuous  with  the 
Malpighian  layer  of  the  epidermis,  g. 
.Canal  of  the  same  through  the  corium. 
h.  Its  passage  through  the  horny  por- 
tion of  the  epidermis,  i.  Perspiratory 
pore. 


480  THE   TISSUES. 

especially  those  clustered  round  the  nuclei  of  the  cells.  In  the 
white  races,  the  granules  are  also  darker  in  certain  parts  of  the 
body,  and  the  cells  become  pigment-cells,  therefore,  as  already  de- 
scribed; as  in  the  areola  and  the  nipple  (especially  during  preg- 
nancy and  after  bearing  children),  in  the  linea  alba,  and  the  face 
during  pregnancy,  &c.  (p.  136).  In  the  negro,  even  the  horny  layer 
(cuticle)  is  also  inclined  to  yellow  or  brownish ;  while  in  the  white 
races  it  is  entirely  colorless,  except  in  the  parts  and  circumstances 
just  mentioned.  It  consists  usually  of  many  layers  of  horny  plates, 
the  lowermost  of  which  suddenly  merge  into  the  subjacent  upper- 
mOvSt  cells  of  the  rete  Malpighii.  That  these  plates  are  still  flat- 
tened cells,  and  contain  a  very  minute  quantity  of  viscid  fluid,  is 
proved  by  the  addition  of  acetic  acid  and  potassa,  which  cause 
them  to  swell  up  and  assume  the  form  of  vesicles,  sometimes,  though 
seldom,  containing  a  rudimentary  nucleus.  In  the  lower  and  mid- 
dle parts  of  the  cuticle,  these  plates  are  pretty  regularly  polygonal 
(4,  5,  or  6  sided) ;  in  the  upper  layers  they  present  more  irregular 
outlines,  and  often  appear  wrinkled  and  folded.  They  vary  from 
T^'oo  ^^  75  0  ^f  ^^  vaoh  in  diameter.  Upon  the  glans penis  and  the 
outer  side  of  the  labia  minora^  the  largest  are  ^\-q  to  g^^  of  an  inch, 
and  on  the  labia  majora  y^^^  to  i^^^  of  an  inch  in  diameter.  All 
these  larger  cells  are  distinctly  nucleated. 

These  plates  being  applied  to  each  other  horizontally,  give  the 
cuticle  a  distinct  lamination.  The  most  superficial  laminas  are 
parallel  to  the  general  surface  of  the  corium,  while  the  deepest  take 
a  direction  parallel  to  the  surface  of  the  papillae.  Thus  depressions 
corresponding  to  the  papillas  in  form  appear  on  the  inner  surface  of 
the  cuticle  (Figs.  321  and  328),  and  into  which  the  papillas,  covered 
by  the  stratum  Malpighii,  projected. 

The  thichiess  of  the  entire  epithelium  of  the  skin  varies  in  differ- 
ent parts;  viz.,  it  is  g^^  to  g^j^  of  an  inch  on  the  chin,  cheeks,  and 
brow,  on  the  eyelids,  and  in  the  external  auditory  passage;  g^^r  to 
■3 J,,,  of  an  inch  on  the  bridge  of  the  nose,  the  breast  and  nipple  of 
a  female,  the  back  of  the  toes  and  the  fingers,  on  the  neck  and  back, 
on  the  inner  and  outer  side  of  the  thigh,  the  scrotum,  and  the  labia 
minora. 

It  is  ^^5  to  yjj  of  an  inch  on  the  edge  of  the  eyelids,  the  male 
chest  and  nipple,  the  hairy  scalp,  the  chin,  penis,  prepuce,  and  glans 
penis;    ,-^2  to  yio  of  an  inch  on  the  red  external  portion  of  the  lips, 


THE   SKIN. 
Fig.  321. 


481 


Under  surface  of  the  cuticle,  detached  by  maceration  from  the  palm  ;  showing  the  double  row  ol' 
depressions  in  which  the  papillje  have  been  lodged,  with  the  hard  epithelium  lining  the  sweat- 
ducts  in  their  course  through  the  coriuia.  Some  of  these  are  contorted  at  the  end,  where  they 
entered  the  sweat-gland.     (Magnified  30  diameters.) 

and  the  back  of  the  hand;  jItj  to  ^\  of  an  inch  on  the  flexor  side 
of  the  fingers  and  toes. 

It  is  3^g  to  5^4  of  an  inch  on  the  palm,  and  j\  to  ^  of  an  inch  iti 
the  sole  of  the  foot;  though  here  the  varieties  are  greatest. 

As  compared  with  the  horny  layer  (cuticle)  alone,  the  stratum 
Malpighii  is  in  some  localities  always  2|  to  4|  times  the  thicker ; 
viz.,  in  all  parts  of  the  face,  in  the  hairy  scalp,  the  penis,  the  scro- 
tum, the  nipple,  and  the  skin  of  the  thorax  in  man;  in  the  labia 
majora  and  minora,  and  on  the  back  of  the  hand  and  neck.  In  the 
glans  penis  the  stratum  Malpighii  and  the  cuticle  are  of  equal  thick- 
ness. In  other  parts  of  the  body  the  two  layers  are  either  equal  in 
thickness,  or  the  horny  layer  is  2  to  5  (or  sometimes  10  to  12)  times 
as  thick  as  the  Malpighian. 

The  thickness  of  the  stratum  Malpighii  (at  the  base  of  the  pa- 
pillte)  varies  between  ^^^^  and  ^j^  of  an  inch.    When  thicker  than 
the  horny  layer,  it  averages  g-J^  of  an  inch;  when  thinner,  i^Vtt  to 
g^^  of  an  inch. 
31 


482  THE   TISSUES. 

Chemical  Composition  and  Physical  Properties  of  the  Shin. 

The  general  composition  of  the  cuticle^  as  one  of  tlie  horny  tis- 
sues, has  already  been  indicated  (p.  235).  Its  cell-walls  are  insoluble 
in  water,  but  concentrated  alkalies  and  concentrated  sulphuric  acid 
easily  dissolve  them;  and  hence  the  skin,  if  wetted  with  these  agents, 
feels  slippery  and  greasy.  The  cuticle  contains  less  sulphur  than 
the  hair  and  nails;  and  hence,  perhaps,  salts  of  lead,  mercury,  and 
bismuth  color  tiie  hair,  but  not  the  epidermis.  Nitrate  of  silver 
colors  it  violet  or  brownish  black;  the  oxide,  chloride,  and  black 
sulphuret  of  silver  being  formed  from  the  chloride  of  sodium  and 
the  sulphur  it  contains.  The  tissue  of  the  cuticle  is,  however,  quite 
unchanged,  the  microscope  merely  detecting  minute  dark  granules 
between  its  elements.  But  strong  solutions  of  the  iodide  and  of  the 
cyanuret  of  potassium  remove  the  color,  by  dissolving  away  the 
horny  plates  themselves. 

The  horn}'-  structure  of  the  epidermis  permits  no  fluids,  except 
those  which  act  chemically  upon  it,  to  pass  through  it;  while  it 
readily  takes  up  gaseous  matters,  or  easily  vaporizable  substances, 
as  ether,  alcohol,  acetic  acid,  ammonia,  ethereal  solutions  of  chloride 
of  iron,  and  alcoholic  solutions  of  acetate  of  lead.  It  also  gives  all 
these  oft'  by  cutaneous  evaporation.  {Krause.)  Water,  ointments, 
and  even  solid  matter  (sulphur,  cinnabar),  pass  through  the  unin- 
jured cuticle ;  but  here  there  is  a  mechanical  intrusion,  in  and 
through  the  sweat-ducts  and  hair  sacs,  to  the  stratum  Malpighii, 
which,  on  the  contrary,  is  easily  penetrated  by  fluids.  Hence,  also, 
the  very  ready  occurrence  of  absorption  after  the  separation  of  the 
horny  layer  and  the  superficial  portion  of  the  Malpighian,  by  a 
blister. 

The  corium  aftbrds  gelatine  on  boiling,  from  the  osteine  contained 
in  its  white  fibrous  tissue.  It  putrefies  with  difficulty,  and  not  at 
all  when  tanned.  Its  toughness  and  slight  elasticity  have  already 
been  mentioned. 

Vessels  of  the  Skin. 
The  arteries  in  the  subcutaneous  areolar  tissue  give  off'  many 
branches  to  the  hair-papilla?  (p.  259),  to  the  fat-lobules  (Fig.  188), 
and  the  smooth  muscular  fibres.  More  externally,  they  supply  the 
sweat-  and  the  sebaceous  glands  (Figs.  138,  135),  and  the  inner  por- 
tion of  the  corium;  and  finally  penetrate  into  its  outer  part,  and 


VESSELS   AND   NERVES   OF   THE   SKIN.  483 

into  the  papillae  themselves,  where  they  terminate  in  a  close  capil- 
lary network.      This  consists — l.s^,  of  a  horizontal  portion  lying 
immediately  under  the  surface  covered  by 
the  Malpighian  layer,  composed  of  vessels  Fig-  322. 

Ts'o^  to  23^15  ^^  ^'^  ^'^^^) ''^^^^  *^^  c^P^^l^^i^s        ,-.     .       ....   ....••;"'.. 

lAir  to  ^^'(55  of  an  inch  in  diameter,  with      •iSv^i(^^.'i^'^i^J'?^54''  \ 

narrow  meshes;  and,  2dly^  of  many  loops     ioWv'jlf  •'  M 

of  the  finest  vessels  (^x^V^  to  ■g^j'Tr^  of  an        \S^^''''.'^^^^/r^ 

inch)  given  oft'  to  the  papillae.    (Fig.  322.)         ^Mi        ^^i^ 

Generally,  each  papilla  has  its  own  capillary       ^  <j/Ji,    ^ f 

loop,  which  runs  either  in  its  axis  or  near      y^^^,,,  „f  thJ'papiUa  from  the 

the   surface,  almost  to    its   apex.       The  com-      ^eel.     a.  Terminal  arterial  twig. 
,  ...       .  .   .  u  Commencing  vein.    (Magnified 

pound  papillas  have  several  loops.  8o  diameters.) 

Lymphatic  vessels  also  exist  in  the  sub- 
cutaneous areolar  tissue,  and  form  a  very  close  network  of  fine 
vessels  in  its  outermost  part,  o|o  to  yg^  of  an  inch  in  diameter. 

The  Nerves  of  the  Skin. 
But  few  nerves  exist  in  the  subcutaneous  areolar  tissue ;  but 
these,  entering  the  corium,  anastomose  frequently,  and  form  rich 
terminal  plexuses.  Of  these,  the  deeper  portions  consist  of  fine 
branches,  still  containing  many  nerve-fibres,  with  wide  meshes ; 
while  the  superficial  portions  consist  of  fibres,  either  single  or 
united  in  pairs,  with  narrow  meshes.  In  this  last  there  also  occur 
(perhaps  not  in  all  the  fibres)  actual  divisions  of  the  nerve-fibres, 
generally  at  an  acute  angle,  into  two  subdivisions ;  and  from  the 
plexus  itself  the  fibres  finally  enter  the  base  of  the  papillae  in  pairs, 
running  to  their  extremities,  and  then  uniting  in  a  loop.  (Fig.  323.) 
The  nerve-fibres  in  the  papillae  vary  from  y^^o  o  to  g^V(j  of  an  inch. 
The  axile  or  tactile  corpuscles  (corpuscula  tactus),  described  by  R. 
Wagner  (Fig.  323),  are  regarded  by  Kolliker  as  consisting  of  col- 
lagenous tissue,  with  much  undeveloped  elastic  tissue.  These  exist 
only  in  a  small  proportion  of  the  papillae — about  1  in  -i  of  those 
on  the  first  joint  of  the  index  finger.  [Meissner.)  They  resemble  a 
fir-cone  in  form,  and  occupy  one-third  to  two-thirds  of  the  width  of 
the  summit  of  the  papilla,  and  one-fourth  to  three-fourths  of  its 
length.  The  conclusion  of  Wagner,  that  the  papilla3  without  these 
corpuscles  contain  vessels  only,  but  not  nerves,  needs  further  con  • 
firmation.  At  any  rate,  dark-bordered  nerve-fibres  are  found  in 
vascular  papillae  without  axile  corpuscles,  in  the  sole  of  the  foot 


484 


THE  TISSUES. 


and  on  the  lips.     His  assertion,  also,  that  the  papillae  containing 
axile  corpuscles  have  no  vessels,  is  not  confirmed  by  Kolliker's 

Fig.  323. 


Two  papillse  from  the  extremities  of  the  fingers,  withont  epithelium,  and  tcith  axile  corpuscles  (a) 
and  nerves  (&).  A.  Simple  papilla  -with  four  nerve-fibres  and  two  terminal  loops  (c).  B.  Compound 
papilla  with  two  vascular  points  with  capillary  loops  (d),  and  one  nervous  point  with  a  terminal 
00  p  (e).  (KUlliker.) 

observations,  though  it  may  apply  to  particular  cases.  It  is  very 
probable  that  the  nerve-fibres  do  not  in  all  cases  enter  into  the  pa- 
pilla at  all,  but  terminate  in  the  superficial  plexus  at  their  base.^ 

Development  of  the  Skin. 

The  corium  consists,  at  first,  entirely  of  cells;  among,  and  from 
which,  subsequently,  the  white  fibres  and  the  elastic  tissue,  the 
vessels  and  nerves  are  formed.  It  evidently  grows  from  within 
outwards,  so  that  the  papillas  are  developed  last  of  all.  It  also  con- 
tinues to  grow  a  long  time  after  birth,  it  being  only  half  as  thick 
in  children  under  seven  years  of  age  as  in  the  adult.  {Krause)  In 
embryo  of  two  months,  it  is  ^uV^  to  i^^^  of  an' inch  thick,  and 
presents  tolerably  distinct  collagenous  tissue.  In  the  fourth  month, 
the  first  lobules  of  fat  appear,  and  the  ridges  of  the  hand  and  the 
sole  of  the  foot. 

The  epitheliuvi  of  the  skin  has  its  first  layers  developed  by  the 
metamorphosis  of  the  most  superficial  of  the  primordial  cells  of  the 
embryo.     The  outermost  layers  of  these  become  the  cuticle,  and 

'  While  Kolliker  maintains  that  the  nerve-fibres  terminate  in  loops  on  the  sur- 
face of  the  axile  corpuscle,  Meissner  regards  the  cross  striae  on  the  latter  as  the 
tennination  of  the  dark-bordered  nerve-fibres. 


DEVELOPMENT   OF   THE   SKIN.  485 

those  underneath,  tlie  stratum  Malpighii.  Then,  as  the  former  be- 
comes detached,  it  is  recruited  from  the  latter.  The  extension  in 
surfiice  of  the  cuticle  implies  a  series  of  desquamations  in  the  em- 
bryo and  the  foetus,  and  which  must  also  occur  after  birth.  The 
multiplication  of  the  cells  in  the  stratum  Malpighii  is  certainly  not 
by  free  cell-development  (p.  120) ;  since  at  no  age  are  free  nuclei 
present  in  it.  (KdUilcer.)  In  the  embryo  of  five  weeks,  there  are 
but  two  layers  of  cells  instead  of  the  epithelium ;  at  fifteen  weeks, 
three  layers  of  cells,  the  two  internal  for  the  stratum  Malpighii;  in 
the  fifth  month,  the  latter  consists  of  many  layers  of  the  smaller 
cells,  and  the  cuticle  of  at  least  two,  of  polygonal  flattened  cells; 
and  at  the  seventh  month,  these  two  layers  are  as  sharply  distin- 
guished from  each  other  as  in  adults.  In  the  new-born  infant  the 
epithelium  resembles  that  of  the  adult,  except  that  it  is  more  easily 
separated  from  the  corium  by  maceration,  and  that  the  stratum 
Malpighii  is  disproportionally  thick,  and  the  cuticle  very  delicate. 

The  desquamations  of  cuticle  during  embryonic  life,  already 
alluded  to,  aid  in  the  formation  of  the  vernix  caseosa,  already  de 
scribed  (p.  226);  this  consisting  of  the  external  epidermic  cells 
mixed  up  with  the  sebaceous  secretion  of  the  skin,  and  containing 
hairs ;  and  which,  especially  from  the  sixth  month  onwards,  covers 
the  whole  surface  of  the  foetus.  It  varies  greatly  in  quantity  in  the 
new-born  child  ;  sometimes  amounting  to  even  S^  drachms. 

The  pigment  in  the  stratum  Malpighii  of  the  negro,  appears  after 
birth.  The  edges  of  the  nails,  and  the  surface  around  the  nipple, 
become  rapidly  tinged  black ;  the  genital  organs  become  colored  on 
the  third  day,  and  the  whole  body  on  the  fifth  and  sixth.  (^Camper.) 
In  Europeans  also,  the  pigment  in  the  areola  is  gradually  developed 
during  the  first  year. 

The  groicth  of  the  corium  presents  no  peculiarities.  The  cuticle 
is  constantly  being  detached  and  repaired,  and  is  thus  constantly 
growing.  The  cells  of  the  stratum  Malpighii  are  developed  from 
plasma  exuded  from  the  bloodvessels  of  the  corium ;  and  of  Avhich 
a  determinate  quantity  always  exists  among  these  cells,  and  even 
those  of  the  cuticle  also.  In  the  deep  fold  of  the  skin  surrounding 
the  glans  penis  and  clitoridis,  this  continuous  desquamation  and  re- 
production of  the  cells  of  the  cuticle  produce  the  substance  (not 
a  secretion,  as  generally  supposed)  called  the  smegma  prceputii.  In 
the  male,  however,  the  secretion  of  Tyson's  glands  may  be  mixed 
with  it;  but  in  the  female,  neither  sebaceous  nor  any  other  glands 


486 


THE   TISSUES. 


exist  on  either  the  prepuce  or  the  glans  clitoridis.  [Kolliker.)    Leh- 
man's analysis  of  the  smegma  has  already  been  given  (p.  227). 

The  corium  is  regenerated  if  entirely  removed ;  but  the  new  de- 
velopment has  neither  papilliB  nor  ridges. 

The  epithelium,  therefore,  though 
regenerated  in  all  cases  when  removed, 
has  none  of  the  usual  elevations  and 
depressions  on  both  its  surfaces,  if  the 
corium  also  has  been  removed.  If 
the  latter  has  remained  uninjured,  the 
new  epithelium  is  rapidly  produced 
and  perfect,  though  it  grows  up  as 
a  whole  from  the  corium  below.  This 
is  well  shown  by  the  application  of  a 
blister. 


Appendages  and  Accessoky  Or- 
gans OF  THE  Skin. 
The  appendages  of  the  skin  are  the 
nails  and  the  hair,  already  described 
(pp.  249 — 68).  The  accessory  organs 
are:  1,  the  sebaceous  glands;  2,  the 
sweat-glands;  and  3,  the  subcutaneous 
bur  see  miicosce. 

1.  The  Subcutaneous  Bursce  Mucosae 
are  merel}^  simple  or  partially  subdi- 
vided reticular  spaces  in  the  subcuta- 
neous areolar  tissue ;  as  over  the  up- 
per extremity  of  the  olecranon,  over 
the  patella,  kc  Their  internal  walls 
are  smooth  but  uneven,  and  are  form- 
ed of  areolar  tissue.  They  contain 
a  viscid  clear  fluid,  but  have  no  epi- 
thelium. 

2.  The  Sebaceous  Glands. — These 
glands  vary  in  form  from  the  simple 
follicle  (Fig.  324,  a)  to  the  racemose 
gland  (Fig.  324,  b).  They  occur  prin- 
cipally upon  the  hairy  parts  of  the 
body,  opening  in   common   with  the 


Sebaceous  glauds  from  tho  noso.  A. 
Simple  follicular  gliiud  without  any  hair. 
B.  Kacemoso  gland,  liaving  a  common 
opening  with  a  hair-sac  ;  a,  glandular  epi- 
thelium, connected  with  b,  tho  Htratum 
Malpighii  of  the  epidermis;  c,  contents  of 
the  glands,  sebaceous  cells,  and  free  fat ; 
d,  the  separate  racemes  of  the  compound 
gland  ;  e,  hair-sac  (root-sheath),  with  the 
hair,  /. — Magnified  50  diameters.  (Kmii- 
ker.) 


ACCESSORY   OKGANS   OF   THE    SKIN. 


487 


The  hairs 


Fig.  325. 


hair-sacs;  and  hence  are  sometimes  termed  the  glands  of  the  hair- 
sacs.  They  in  fact  occur,  of  the  hairless  parts,  only  on  the  labia 
minora,  and  the  glans  penis  and  clitoridis,  and  the  prepuce  of  both 
the  male  and  the  female.  The  opening  of  the  gland  is  sometimes 
common  with  that  of  the  hair-sacs,  sometimes  it  terminates  in  the 
latter,  and  sometimes  tlie  hair-sac  is  smallest,  and  the  hairs  come 
out  through  the  glandular  opening  itself.  (Fig.  324,  b.)  Generally, 
the  small  hair-sacs  have  the  larger  glands,  and  vice  versa. 
of  the  scalp  have  the  smallest,  ^i^ 
to  -^^r,  of  an  inch  in  diameter,  and 
these  are  simple  follicles  lodged  in 
the  superficial  portion  of  the  coriura. 
The  largest  of  all  exist  on  the  mons 
veneris^  the  labia  majora.,  and  the 
scrotum,  where  they  are  compound, 
and  found  in  the  deepest  portions  of 
the  corium.  Frequently  two  or  more 
(even  five)  glands  are  connected  with 
a  single  hair  (Fig.  135) ;  there  being 
generally  two  in  the  scalp.  The 
glands  upon  the  nose  (also  the  ante- 
rior half  of  the  penis,  and  the  areola), 
often  attain  to  a  colossal  size  and 
peculiar  forms.     (Fig.  325.) 

The  sebaceous  glands  on  the  glans 
penis  and  the  inner  lamella  of  the 
prepuce,  called  Tyson's  glands,  some- 
times occur  in  very  small  number, 
and  sometimes  in  hundreds.  Gene- 
rally, ten  to  fifty  are  found  on  the 
prepuce,  and  mostly  racemose;  while 
on  the  glans  they  may  be  totally  ab- 
sent, or  may  exist  in  its  anterior  sur- 
face in  great  numbers  (even  to  one  hundred)- 
simple. 

The  Meibomian  glands  in  the  eyelids  must  also  be  regarded  as  a 
larger  kind  of  sebaceous  gland.     (Fig.  136.) 

In  their  minute  structure  the  sebaceous  glands  consist  of — 1,  an 
external  delicate  layer  of  collagenous  tissue  (or  basement-mem- 
brane— KoUiker),  continued  from  the  hair-sac,  or  the  coriam  where 


A  large  racemose  sebaceous  gland  from 
the  nose  with  a  little  hair-sac  opening  into 
it.  The  letters  (a—/)  as  in  Fig.  324.— Mag- 
nified 50  diameters.     [KoUiker.) 


-beino;  here  more 


488 


THE   TISSUES. 


no  hairs  are  present ;  within  which  are  (2)  masses  of  cells.  The 
latter  are  arranged,  first  in  a  single,  and  rarely  in  a  double  layer,  in 
contact  with  the  basement-membrane  ;  internally  to  which  are  other 
cells  containing  more  fat,  and  which  pass  into  the  innermost  of  the 
cells  which  are  larger  (=^^0  to  ^Jg  of  an  inch),  and  so  filled  with 
colorless  fat  that  they  might  be  termed  sebaceous  cells.    (Fig.  826.) 

Fig.  326. 


A.  One  of  the  caeca  of  a  common  sebaceous  gland  ;  a,  epithelium  sharply  defined,  but  without  any 
basement-membrane,  and  passing  continuously  into  the  fat-cells,  6  (their  contours  drawn  too  indis- 
tinctly), in  the  interior  of  the  glandular  tube.  B.  Sebaceous  cells  from  a,  and  the  cutaneous  seba- 
ceous matter;  a,  smaller  nucleated  cells,  still  more  of  an  epithelial  character,  and  containing  but 
little  fat;  6,  cells  abounding  in  fat  without  visible  nucleus  ;  c,  cell  in  which  the  fat  is  beginning  to 
flow  into  one  mass  ;  d,  cell  with  one  fat  drop  ;  e, /,  cell  from  which  the  fat  bus  partially  escaped. — 
Magnified  350  diameters.     {Kiilliker.) 

The  fat  in  them  sometimes  appears  in  the  form  of  a  single  drop 
quite  filling  the  cells;  at  others  it  still  retains  the  form  of  distinct 
small  drops.  In  the  former  case,  they  resemble  the  adipose  cells. 
By  endogenous  development  now  cells  are  constantly  produced  in 
the  bottom  of  the  glands,  and  thus  the  pre-existing  cells  are  thrust 
forward,  and  finally  excreted  through  the  neck  of  the  gland  upon 
the  cuticle. 

It  appears  that  no  nerves  are  distributed  to  the  sebaceous  glands. 
Nor  are  vessels  distributed  upon  and  between  their  lobules ;  while 
numerous  vessels  and  capillaries  exist  around  the  glands. 

These  glands  are  developed  from  about  the  end  of  the  fourth 
month  of  embryonic  life,  together  with  the  hairs,  since  they  appear 
as  outgrowths  or  processes  of  the  hair-sacs.  Subsequently  the  pro- 
cesses become  filled  with  the  cells  above  described;  and,  finally, 
they  open  on  the  surface,  and  the  structure  of  the  gland  is  now 
complete.  All  the  glands  are  at  first  simple,  and  most  are  so  in  the 
foetus  of  seven  months ;  and  the  compound  are  formed  by  processes 
proceeding  from  these.     Sometimes  a  simple  gland  growing  rapidly 


THE   SWEAT-GLANDS.  489 

completely  surrounds  a  hair-sac  on  all  sides,  constituting  a  glandu- 
lar rosette. 

The  sebaceous  glands  grow  after  birth.  In  fact,  those  of  the 
labia  minora  do  not  exist  at  all  at  birth. 

The  composition  and  uses  of  the  sebaceous  secretion  are  specified 
on  page  227. 

3.  The  Sudoriferous  or  Sweat- Glands. — These  consist  of  a  single 
delicate  convoluted  tube,  which  secretes  the  sweat.  They  occur  on 
the  whole  surface  of  the  skin,  except  the  concave  side  of  the  con- 
cha of  the  ear,  and  the  external  auditory  meatus,  the  glans  penis, 
the  inner  lamella  of  the  prepuce,  and  a  few  other  localities — and 
open  upon  it  by  numerous  fine  apertures. 

Each  sweat-gland  may  be  divided  into  the  gland  proper  and  the 
excretorij  duct.  (Figs.  138,  317,  321.)  The  proper  gland  is  rounded 
or  elongated,  yellowish,  or  yellowish-red,  and  g\  to  gV  of  an  inch 
in  diameter.  On  the  eyelids,  however,  and  some  other  parts,  they 
are  only  ji^  of  an  inch  ;  while  on  the  areola  they  are  o^  of  an  inch, 
and  in  the  hairy  parts  of  the  axilla  even  o\  to  \  of  an  inch  thick, 
and  X2  to  \  of  an  inch  broad.  They  are  mostly  lodged  in  the 
deeper  layer  of  the  corium,  sometimes  more  superficially,  and  often 
in  the  subcutaneous  areolar  tissue  among  the  hair-sacs. 

Numher  of  the  Sweat- Glands, — Krause  states  that  in  a  square  inch 
of  the  skin  there  are  between  400  and  600  glands  on  the  back  of 
the  trunk,  the  cheeks,  the  upper  arm,  and  the  thigh;  924  to  1,090 
on  the  anterior  part  of  the  trunk,  on  the  neck,  brow,  forearm,  back 
of  the  hand,  and  foot;  2,685  on  the  sole  of  the  foot;  and  2,736  on 
the  palm  of  the  hand.  Their  total  number,  including  those  of  the 
axilla,  is  estimated  at  2,381,248;  and  their  volume,  including  the 
latter,  39,653  cubic  inches. 

The  aggregate  length  of  all  the  excretory  ducts  of  the  s^^'eat-glands 
in  the  body  has  been  estimated  by  Wilson'  at  28  miles. 

1.  In  their  minute  structure,  the  sweat-glands  usually  consist  of 
a  single  canal,  pretty  uniform  in  diameter  throughout  its  length 
(which  Krause  once  found  to  be  x'g  of  an  inch),  twined  into  a  coil, 
and  terminating  on  the  surface  on  the  interior  of  the  latter  in  a 
slightly  enlarged  blind  extremity.  (Fig.  138.)  Most  of  these,  having 
thill  walls,  possess  an  external  investment  of  embryonic  collagenous 

'  Treatise  on  Diseases  of  the  Skin. 


490 


THE   TISSUES, 


tissue,  with  scattered  elongated  nuclei,  and  lined  apparently  by  a 
basement-membrane,  supporting  a  single,  double,  or  multiple  layer 
of  polygonal  cells,  corresponding  to  the  deep  cells  of  compound 
conoidal  epithelium,  except  that  they  generally  contain  a  few  fatty, 
and  still  more  frequently  yellowish  or  brownish,  pigment-granules. 
(Fig.  327,  A.)     The  rest,  called  the  thick-coated  canals,  contain  be- 

Fig.  327. 


Sweat-ducts.  A.  One  with  thin  walls  and  a  central  cavity,  without  a  muscular  coat,  from  the 
hand:  «,  connective  investment ;  6,  epithelium  ;  c,  cavity.  B.  A  portion  of  a  canal  without  a  cavity, 
and  with  a  delicate  muscular  layer,  from  the  scrotum:  a,  connective  tissue ;  b,  muscular  layer  ;  c, 
cells  which  fill  the  glandular  canal,  with  yellow  granules  among  their  contents. — Magnified  350 
diameters.  (Kolliker.) 

tween  the  two  layers  just  described  a  middle  layer  of  smooth  mus- 
cular fibre-cells  running  longitudinally.  (Fig.  327,  B.)  This  is  the 
case  with  the  large  glands  of  the  axilla,  of  the  root  of  the  penis, 
and  the  nipple ;  and  the  coecal  extremity  of  the  canal  is  supplied 
with  muscular  fibre-cells  in  the  scrotum,  labia  inajora,  mons  veneris, 
and  some  other  parts. 

The  size  of  the  canal  varies  from  gso  to  3',^,  and  averages  about 
■^^jj  of  an  inch.  The  walls  are  g^yVT;  to  iAtj  ^^  f^»  i'^ch  thick;  the 
epithelium,  ^tfVtt;  ^^^^  the  cavity,  or  lumen,  -jtjVtt  to  rsVir  of  an  inch. 
Tlie  largest  glands  have  canals  ^^^  to  jj-^  of  an  inch  in  diameter, 
with  walls  ^Atj  of  ^^  i"ch  thick. 

The  coils  of  the  proper  glands  are  penetrated  by  collagenous 
tissue  interspersed  witli  fat-celLs;  which  su])ports  the  vessels,  and 
unites  the  separate  convolutions.  Tlic  arrangement  of  the  vessels 
is  seen  in  Fig.  138.     No  nerves  have  yet  been  found  in  the  glands. 

2.  The  svjeal-diccts  are  continuous  with  the   upper  end  of  the 


THE   SWEAT-GLANDS. 


491 


glandular  coil,  and  ascend  vertically  through  the  corium,  penetrating 
between  the  papillas  into  the  epithelium.  Here  they  twist  like  a 
corkscrew,  and,  according  to  the  thickness  of  the  cuticle,  make  two 
to  sixteen  spiral  turns,  and  ter- 
minate by  small  round  or  funnel- 
shaped  apertures  (^J^^^,  to  jIu  of 
an  inch),  called  the  sweat-pores, 
on  the  free  surface  of  the  cuticle. 
(Fig.  328.)  They  retain  their  epi- 
thelium, consisting  of  at  least 
two  layers  of  cells,  till  tlaey  reach 
the  surface  of  the  corium.  But 
while  traversing  the  stratum  Mal- 
pighii  and  the  cuticle,  they  are 
merely  bounded  by  layers  of 
cells.  Sometimes  the  excretory 
ducts  of  two  glands  unite  into 
one.  {Krause) 

These  glands  are  developed  ori- 
ginally as  solid  flask-shaped  pro- 
cesses of  the  stratum  Malpighii 
projecting  into  the  corium,  and 
are  very  similar  to  the  hair-sacs. 
They  first  appear  in  the  fifth 
month  of  embryonic  life.  At 
the  seventh  month  the  sweat- 
duct  is  seen  perforating  the  cu- 
ticle, and  the  gland  has  pene- 
trated downwards  to  the  inner 
portion  of  the  corium,  and  be- 
come bent  like  a  hook,  indicative         a.  vertical  section  of  the  cuUcle,  fnmtbeheel 

of    the    future    coils.       Soon    after  '^"''''^"^  "^^  maceration.     The  epithelium  of  the 

sweat-duct  continuous  trlth  the  cuticle  has  been 

this,   the    gland    acquires    the    ap-  drawn  out  ofthe  tube  of  basement-membrane,  as 

pearance  it  presents  in  the  adult,  i^'^^"'.;'^«  gland  where U begins  to  becontorted. 

"■  ^  '  The  cavity  of  the  duct  IS  seen  dilating  as  It  enters 

and    probably    no    new     ones    are  "^^  cutlcle,  and  then  stretching  up  to  the  surface 

developed  after  birth.  ";7;^;  the  epidermic  lamm..    The  deep  surface 

i^  ot  the  duct  is  continuous  with  the  surface  of  the 

The    secretion   afforded    bj"    the  cavities  in  which  the  paplllje  are  lodged.    6.  Duct 

-I       •  n  T         T       T  IT  at  its  entrance  Into  the  cuticle,  more  highly  mac- 

sudoriferous    glands    has    already  nlfied.     (Magnified  35  diameters.) 

been  described  (p.  229). 

The  ceruminous  glands  of  the  ear  may  be  regarded,  histologi- 


492 


THE   TISSUES. 


callj,  as  a  variety  of  sweat-glands.     Fig.  329  represents  their  va- 
rious forms  and  relations  to  the  hair-sacs.     Thej  exist  only  in  the 

Fig.  329. 


Cutaneous  glandule  of  external  meatus  auditorius.  A.  Section  of  the  cerium:  2,  2,  hairs;  3,  3, 
superficial  sebaceous  glands  ;  1, 1,  larger  and  deeper-seated  glands,  by  which  the  cerumen  is  secreted. 
B.  A,  hair  perforating  the  epidermis  at  3:  1,  1,  sebaceous  glands,  with  their  excretory  ducts  (2,  2)  ; 
4,  base  of  the  hair  in  its  double  follicle  (5,  6).  C.  Cerumen-gland  formed  by  the  contorted  tube  (1, 1) 
of  the  excretory  duct  (2) ;  4,  vascular  trunk  and  ramifications.  The  last  two  figures  highly  magni- 
fied ;  the  first,  3  diameters. 

cartilaginous  portion  of  the  external  auditory  meatus ;  being  situ- 
ated between  the  lining  membrane  of  the  passage  and  the  cartilage, 
or  the  fibrous  substance  supplying  its  place,  in  a  tough  subcuta- 
neous tissue  containing  but  little  fat. 

The  properties  and  uses  of  the  cerumen  have  already  been  spe- 
cified (p.  228) ;  it  being  associated  physiologically  with  the  seba- 
ceous secretion. 

Functions  of  the  Skin. 
The  skin  fulfils  a  variety  of  functions. 

1.  Of  protection,  as  the  common  tegument  of  the  body. 

2.  As  an  absorbing  organ.  Gases  are  rapidly  absorbed,  and  cer- 
tain solid  and  fluid  substances  (p.  280).  Even  nutritious  fluids  are 
absorbed  by  the  skin,  as  proved  by  the  effects  of  nutritious  baths. 
Here  the  fluid  probably  enters  to  the  stratum  Malpighii  mainly 
through  the  sweat-ducts  (p.  482). 


PATHOLOGICAL   STATES   OF   THE   SKIN.  493 

3.  Hence  the  skin  is  an  aerating  organ,  as  accessory  to  the  lungs; 
oxygen  being  absorbed  directly  into  its  bloodvessels. 

4.  The  skin  is  a  secreting  organ,  aflfording  the  sweat  and  the 
sebaceous  fluid. 

5.  The  contraction  of  the  skin  is  shown  in  the  cutis  anserina  (so 
called),  the  erection  of  the  nipple,  and  the  wrinkling  of  the  skin  of 
the  scrotum  and  the  penis  (p.  477). 

6.  But  the  skin  manifests  its  most  important  function  as  the 
organ  of  the  sense  of  touch.  And  it  is  a  singular  fact  that  all 
points  of  the  skin  are  sensitive,  though  nerves  cannot  be  demon- 
strated in  all,  or  even  in  the  majority,  of  the  papillae.  KoUiker, 
however,  finds  that  the  same  point  is  sometimes  sensitive,  and  some- 
times not  so.  Probably  the  nervous  plexus  at  the  base  of  the 
papillae,  and  not  those  in  the  latter  alone,  are  the  media  of  the 
sensibility  of  the  skin.  The  vai'ious  modifications  of  tactile  im- 
pressions, as  those  of  pressure,  warmth  and  cold,  of  orgasm,  of  ticjr- 
ling,  pricking,  burning,  and  pain,  are  not  well  accounted  for.  The 
thickness  of  the  cuticle  of  a  part,  the  paucity  or  abundance  of 
nerves,  the  superficial  or  deep  position  of  the  nerve-fibres,  the 
thickness  or  delicacy  of  their  neurilemma,  &c.,  must  doubtless  be 
taken  into  consideration;  and,  on  the  other  hand,  also,  the  agents 
producing  the  sensations  named. 

Pathological  Slates  of  the  Skin. 

1.  Pathological  colorations  of  the  epithelium  of  the  skin  have 
already  been  mentioned  (p.  137).  A  local  thickening  of  it  from 
continued  pressure  constitutes  the  clavus  or  corn,  and  its  other 
morbid  states  are  mentioned  on  page  247. 

In  the  vesicular  diseases  of  the  skin  (pemphigus,  &c.),  an  exuda- 
tion of  plasma,  occurring  from  the  vessels  of  the  corium  into  the 
stratum  Malpighii,  causes  a  limited  elevation  of  the  cuticle.  In 
eczema,  herpes,  and  miliaria,  the  vesicles  are  very  small.  In  ich- 
thyosis the  cuticle  is  much  thickened. 

IT.  The  corium  may  (1)  become  generally  atrophied  in  wasting 
chronic  diseases  (tuberculosis,  syphilis,  &c.);  it  becoming  thinner 
and  smoother  on  its  surface,  and  the  sebaceous  and  perspiratory 
glands,  and  the  hairs,  even,  becoming  atrophied  or  disappearing. 
Local  atrophy  may  be  produced  by  pressure  and  other  causes. 

2.  New  formations  of  areolar  tissue  in  the  corium  (papilloma, 
&c.)  have  already  been  described  (p.  247). 

8.  The  corium  is  also  the  seat  of  disease  in  all  the  exanthemata 
(scarlatina,  rubeola,  &c.) ;  most  of  them  affecting  the  papillary  por- 
tion more  especially. 

4.  In  variola,  papulce,  (so  called)  are  first  formed  by  exudation 


494  THE   TISSUES. 

from  tlae  capillaries  mainly  of  the  papilla3,  which  subsequently  ex- 
tends to  the  stratum  Malpighii,  producing  a  vesicle ;  and  which 
finally  becomes  a  pustule,  since  pus  is  formed  in  it.  The  centre  of 
the  pustule  is  depressed,  from  the  fact  that  the  opening  of  a  seba- 
ceous gland  and  a  hair-sac  penetrates  there ;  and  which  does  not 
allow  the  cuticle  there  to  become  detached  and  elevated,  since  it  is 
connected  with  them. 

5.  In  measles,  lichen,  and  prurigo,  papulas  alone  are  produced. 
There,  also,  the  vascular  injection  is  confined  to  the  most  super- 
ficial layers  of  the  corium.  In  inveterate  cases,  however  (of  pru- 
rigo), the  exudation  extends  to  the  deeper  layers,  and  the  hairs  and 
sebaceous  glands  disappear. 

6.  In  verrucce,  or  warts,  the  papilla  become  hypertrophied. 

III.  The  sebaceous  glands  become,  1,  hypertrophied  in  the  akrothy- 
mion,  or  moist  wart,  and  in  ncevus pilosus.  2.  They  become  atrophied, 
or  entirely  disappear,  when  the  hairs  fall  out,  ^.  e.  on  bald  places.  3. 
The  comedones  are  mere  distensions  of  the  sebaceous  glands  and  the 
hair-sacs  with  sebaceous  matter,  and  are  most  frequent  where  the 
glands  are  largest,  as  on  the  nose,  lips,  chin,  ear,  areola,  and  scro- 
tum. Milium  is  due  to  a  similar  distension  of  the  sebaceous  folli- 
cles alone ;  consisting  of  white  spots  on  the  eyelids,  the  root  of  the 
nose,  the  ear,  the  scrotum,  &c.  In  both  these  cases,  the  apertures 
are  obliterated  or  entirely  closed.  4.  Finally,  steatoma,  especially 
as  it  occurs  on  the  scalp,  is  to  be  regarded  merely  as  a  colossal  se- 
baceous gland  distended  with  its  secretion;  and  atheroma  and  me- 
liceris,  if  occurring  in  the  corium,  must  be  referred  to  the  same 
category. 

5.  The  acarus  foUiculorum  residing  in  healthy  and  distended 
hair-sacs  and  sebaceous  glands,  has  been  shown.     (Fig.  134.) 

6.  New  formations  of  sebaceous  glands  have  been  found  in  an 
ovarian  cyst  in  connection  with  hair.  Indeed,  they  may  probably 
occur  in  any  part  containing  new  formations  of  hair-sacs.  A  new 
development  of  sebaceous  glands  occurs  in  cicatrices  in  the  skin,  of 
some  years'  standing.  (  Von  Bdrensprung). 

IV.  Of  the  pathological  conditions  of  the  sweat-glands  but  little 
is  known.  In  elephantiasis  Groecorum  they  become  hypertrophied  ; 
while  they  are  atrophied  in  case  of  corns,  and  the  sweat-duct  dis- 
appears in  the  outer  layer  of  the  cuticle. 

Neio  formations  of  sweat-ducts  occur  in  connection  with  those  of 
hair  and  .sebaceous  glands,  as  in  ovarian  cysts;  and  in  Mohr's  case 
of  a  large  cavity  in  the  lung  lined  by  a  membrane  in  all  its  ele- 
ments like  the  skin  (with  a  subcutaneous  areolar  tissue  under  it), 
and  on  which  hairs,  sebaceous  follicles,  and  papillai  were  deve- 
loped. 

II.  The  Mucous  Membranes. 
Mucous  membranes  line  the  cavities  opening  externally,  and,  like 
the  skin,  consist  of  a  corium,  a  basement-membrane,  and  an  epithe 


THE   MUCOUS   MEMBRANES.  495 

lium.  The  basement-membrane  is  like  that  of  the  skin.  The 
corium  is  also  composed  of  collagenous  and  elastic  tissue,  contains 
vessels,  nerves,  smooth  muscular  fibres,  glands,  papillas,  and  other 
peculiar  processes  (villi).  Beneath  the  corium  there  is,  in  most 
parts,  a  layer  of  submucous  areolar  tissue.  The  development  an(J 
regeneration  of  mucous  membranes  also  resemble  those  of  the  skin 
so  nearly  as  not  to  demand  a  separate  consideration. 

The  mucous  membranes  present  marked  differences  in  structure 
in  different  situations.  They  will,  therefore,  be  described  separately, 
in  connection  with  the  other  structural  elements  of  the  organs,  re- 
spectively, of  which  they  form  a  part,  viz: — 

1.  In  the  Alimentary  Canal. 

2.  "      Urinary  Apparatus. 

3.  "      Genital  Apparatus. 

4.  "      Air-passages. 

Functions  of  the  Mucous  Memhranes. 
All  the  raucous  membranes  are,  1,  protective  of  the  passages  lined 
by  them ;  2,  they  secrete  mucus,  of  different  kinds  in  different  parts 
(p.  195);  3,  they  absorb  also  in  certain  parts;  e.  g.  the  villi  of  the 
small  intestine,  &c. ;  4,  they  constitute  an  aerating  surface  to  some 
extent  (e.  g.  in  air-passages) ;  5,  some  portions  of  these  membranes 
manifest  the  sense  of  touch  also  (lips,  genital  organs,  &c.). 

Pathological  States  of  the  Mucous  Membranes. 

1.  Atrophy  of  mucous  membrane  is  rare  {EngeJ)\  but  is  seen  in 
the  alimentary  canal  of  the  aged.  Here  the  gastric  mucous  mem- 
brane becomes  less  plicated  and  smoother;  while  the  peptic  glands 
are  diminished  in  number.  In  the  duodenum,  Brunner's  glands 
become  atrophied,  and  the  villi  of  the  small  intestine  become  clouded 
from  the  apex  towards  the  base,  pigmented,  lessened  in  size  (espe- 
cially transversely),  and  even  in  number  also.  The  valvulae  conni- 
ventes  are  also  less  prominent,  and  the  Peyerian  and  solitary  glands 
collapse ;  their  situation  being  indicated  merely  by  a  pigmented 
border. 

2.  Inflammatory  exudations  on  the  mucous  membranes  (except 
the  mouth,  oesophagus,  vagina,  and  palpebrse),  generally  at  once 
detach  the  epithelium ;  and,  therefore,  no  vesicles  form  upon  them, 
except  in  the  parts  mentioned.  Thus,  the  exudation  may  be  at 
once  examined.  It  is  also  not  so  generally  circumscribed,  as  in  the 
case  of  the  skin;  and  the  submucous  tissue  and  the  glands  it  con- 
tains are  very  frequently  involved.  Hence  the  membrane  becomes 
thickened  and  swollen.     Extravasation  of  blood  is  also  more  liable 


496  THE   TISSUES. 

to  occur  from  the  weaker  vessels;  and  hence  eccliymoses  are  very 
common.  The^jo/^^^i,  so  called,  of  the  stomach,  are  merely  groups 
of  peptic  glands,  rendered  prominent  by  an  exudation  deposited 
around  them. 

3.  The  thinness  of  the  corium  of  the  mucous  membrane  accounts 
for  its  tendency  to  losses  of  substance  by  ulceration;  the  bottoms 
of  which  are  covered  by  various  products  (exudation).  The  latter 
sometimes  rise  like  a  plug  above  the  level  of  the  membrane  (as  in 
typhoid  fever).  Vegetable  parasites  are  also  frequently  developed 
in  exudations  on  mucous  membranes. 

III.  The  Serous  Membranes. 

The  true  serous  membranes  are  the  peritoneum,  the  pleura,  the 
tunica  vaginalis  testis,  and  the  pericardium.  All  these  have  a  sim- 
ple scaly  epithelium  (p.  238,  and  Fig.  140),  generally  a  thinner 
corium  than  the  mucous  membrane,  and  which  presents  neither 
papillee  nor  glands ;  and  constitute  closed  cavities,  moistened  by  the 
secretion  of  their  epithelial  cells,  and  an  accompanying  transudation 
(pp.  180 — 1).  They  will  be  described  in  connection  with  the  parts 
and  organs  into  the  structure  of  which  they  respectively  enter. 
The  tunica  vaginalis  is  originally  an  offset  from  the  peritoneum. 

The  synovial  membranes  are  often  called  serous  membranes;  as 
are  also  the  bursae  mucosas  and  the  vaginal  sheaths  of  tendons.  It 
has,  however,  been  shown  that  histologically  they  are  not  such, 
since  they  do  not  form  closed  cavities  (p.  344,  and  Fig.  233).  The 
arachnoid  also  has  but  a  single  layer  (p.  469)  and  the  ependyma  of 
the  ventricles  has  not  everywhere  a  corium  (p.  469).  The  arach- 
noid, however,  normally  presents  villi;  which,  becoming  enlarged, 
constitute  the  Pacchioniaa  bodies. 

Function  of  Serous  Membranes.  * 

The  serous  membranes  proper,  merely  subserve  the  mechanical 
purpose  of  facilitating  motion  of  one  part  on  another,  and  diminish- 
ing friction ;  both  by  the  smoothness  of  their  surface  and  the  secre- 
tion they  produce  (p.  18 1). 

An  abnormal  accumulation  of  the  natural  secretion  of  the  serous 
membranes  in  their  cavities,  constitutes  the  various  forms  of  dropsy; 
e.g.  in  the  pleural  cavity,  hydrotkorax ;  in  the  peritoneal,  ascites;  in 
the  tunica  vaginalis,  liydrocele ;  and  in  the  pericardium,  hydrops  pe- 
ricardii. An  exudation  upon  the  pleura  becoming  degenerated  into 
pus,  cunstitutes  empyema.  The  conversion  of  exudations  into  new 
formations  is  explained  under  the  next  head. 


FALSE   MEMBRANES.  497 


IV.  False  Membranes. 


This  expression  is  a  very  objectionable  one;  since  it  may  either 
mean  merely  a  coagulated  exudation,  spread  upon  a  surface,  like  a 
membrane,  or  the  same  exudation  after  it  has  become  organized.  £J. 
g.  the  merely  fibrillated  and  never  vascular  exudation  of  croup,  is 
termed  a  false  membrane,  as  well  as  the  highly  vascular  membrani- 
form  formation,  so  common  on  the  surface  of  the  pleura  in  conse- 
quence of  inflammation  of  this  membrane.  The  former  should  be 
called  merely  a  coagulated  exudation;  while  the  latter  may  be  termed 
0.  false  membrane^  if  we  intend  by  this  expression  to  indicate  the  fact 
shown  by  the  microscope,  that  these  formations  are  not  (histologi- 
cally) membranes,  though  they  sometimes,  from  their  form,  appear 
to  the  unaided  eye  to  be  such. 

False  membranes  are,  therefore  (if  the  term  is  to  be  retained), 
more  or  less  organized  exudations  of  plasma^  and  are  developed  espe- 
cially upon  serous  membranes  (p.  188,  2).  They,  however,  present 
all  grades  of  development  and  vascularity,  according  to  the  time 
elapsing  since  the  occurrence  of  exudation.  When  fully  formed, 
they  consist  of  a  layer  of  imperfectly  developed  areolar  tissue,  con- 
taining a  vascular  network,  and  sometimes  ev^  nerves  also,  and 
lymphatics.  Consequently,  they  are  really  mere  new  formations  of 
areolar  tissue. 

False  membranes  being  a  new  formation  are  prone  to  involution, 
and  ultimately  may  entirely  disappear.  Fatty  degeneration  in  them 
is  very  common.  They  are  also  frequently  the  seat  of  pathological 
epigeneses,  especially  of  tubercle. 

The  hands  and  adhesions  so  frequently  resulting  from  pleuritis 
and  peritonitis,  are  histologically  identical  with  false  membranes; 
being  also  new  formations  of  areolar  tissue. 

New  membranes  are  sometimes  formed  to  cover  the  surface  of  per- 
manent adventitious  cavities;  e.  g.  the  membrane  lining  cavities  in 
the  lung,  formed  by  the  removal  of  a  mass  of  tuberculous  depo- 
sit, &c. 

A  new  formation  of  epithelium  occurs  in  many  pathological  cysts; 
of  the  internal  surface  of  which  the  new  formation  constitutes  the 
lining. 


32 


498  THE   TISSUES. 


CHAPTEE   XII. 


THE   VASCULAR   SYSTEM. 


The  vascular  system  consists  of  the  heart,  the  bloodvessels,  and 
the  lymphatic  vessels. 

I.  The  Heart. 

The  heart  is  a  thick  muscular  organ,  divided  into  four  cavities, 
covered  externally  by  a  serous  membrane — the  pericardium — and 
lined  internally  by  the  endocardium^  a  continuation  of  the  inner 
tunic  of  the  large  vessels. 

The  'pericardium  presents  two  layers;  the  outer  (sero-fibrous  layer) 
being  much  the  thicker,  and  fibrous  in  its  external  portion.  The 
inner  layer,  much  thinner,  is  very  intimately  attached  to  the  muscu- 
lar fibres  of  the  heart,  except  over  the  sulci  containing  the  vessels 
and  nerves,  where  it  is  separated  by  common  adipose  tissue.  Some- 
times, however,  the  fatty  sub-serous  layer  extends  almost  over  the 
whole  heart.  The  scaly  epithelium  of  the  pericardium  contains 
one  or  two  layers  of  cells,  and  presents  no  peculiarities.  But  few 
lymphatics  exist  on  the  outer  layer,  while  they  are  more  abundant 
in  the  muscular  substance  of  the  heart.  Subdivisions  of  the  dia- 
phragmatic and  recurrent  laryngeal  nerves  have  been  demonstrated 
by  Luschka  in  the  outer  layer. 

The  muscular  fibres  of  the  heart  are  of  the  transversely  striated 
kind,  but  they  are  about  one-third  smaller  than  those  of  the  volun- 
tary muscles  (g^Vir  to  t^Vt^  o^  ^^  inch),  and  are  often  more  distinctly 
striated  in  the  longitudinal  than  the  transverse  direction.  They 
also  almost  always  contain  minute  fatty  granules,  arranged  in  a 
series  in  their  axes.  Their  myolemma  is  very  delicate,  and  often 
not  to  be  seen  at  all.  The  most  striking  peculiarity  is,  however, 
the  intimate  union  of  the  fibres;  they  being  everywhere  separated 
by  a  very  scanty  connective  tissue,  and  never  forming  manifestly 
distinct  fasciculi.  Besides,  anastomoses  of  the  fibres  exist  (Fig. 
330),  and  also  true  divisions. 

For  the  complex  course  of  the  fibres  of  the  heart,  we  refer  to  the 


THE   HEART. 


499 


Anastomosing  muscu- 
lar libres  from  (he  hu- 
man heart.    (K  Hiker.) 


works  on  anatomy.     The  muscular  structures  of  Fig.  330. 

the  auricles  and  ventricles  are  completely  distinct; 
both,  however,  originating  chiefly  from  the  oska 
venosa  of  the  ventricles,  where  the  so-called  fibro- 
cartilaginous rinws  are  situated. 

The  endocardium  is  a  whitish  membrane  cover- 
ing all  the  internal  surface  of  the  heart,  as  well  as 
the  columnas  carneae,  the  chordae  tendinese,  and  the 
valves.  It  is  thickest  {^^  of  an  inch)  in  the  left 
auricle,  and  thinnest  in  the  ventricles.  It  consists 
of  two  layers:  Is^,  a  scaly  epithelium  of  one  or 
two  layers  of  clear,  flattened,  nucleated  cells,  rest- 
ing, without  any  apparent  basement-membrane, 
upon  the  surface  of,  2c%,  the  elastic  layer.  The 
latter,  determining  the  varying  thickness  of  the  endocardium,  has 
its  superficial  layer  made  up  of  very  fine,  longitudinal,  elastic 
fibres,  and  the  remainder  of  areolar  tissue,  with  scattered  nuclei. 
In  the  auricles,  this  membrane  becomes  almost  entirely  an  elastic 
•  membrane,  and  is  therefore  quite  j^ellow.  It  is  very  delicate  over 
the  chordge  tendine«.  Under  the  endocardium  lies  a  very  deli- 
cate stratum  of  areolar  tissue,  attaching  it  to  the  muscular  fibres. 
The  chordce  iendinece  are  composed  of  collagenous  tissue,  like  the 
tendons. 

The  auricido-ventricular  valves  present  three  layers — a  middle 
one  of  areolar  tissue  with  numerous  elastic  networks,  and  two 
lamellae  of  the  endocardium.  Towards  their  free  borders,  these 
three  are  condensed,  as  it  were, 

into  a  single  layer  of  areolar  tis-  Fig-  331. 

sue  and  elastic  networks,  over 
which  the  epithelium  is  contin- 
ued. The  semilu7iar  valves  pre- 
sent the  same  condition  as  the 
free  borders  of  the  preceding. 
(Fig.  381.) 

The  vessels  of  the  heart  present  only  the  following  peculiarities. 
The  capillaries  often  encompass  several  of  the  fibres  in  common,  on 
account  of  the  small  size  of  the  latter.  The  endocardium  has  very 
few  vessels,  while  they  are  plentifully  distributed  to  the  subjacent 
layer  of  areolar  tissue.  A  few  vessels  are  seen  in  the  auriculo- 
ventricular  valves,  but  never  exist  in  the  semilunar.     Lymphatics 


Elastic  layer  of  a  semilunar  valve 
eudocarilium. 


beneath  the 


500 


THE    TISSUES. 


exist  on  the  muscular  substance  of  the  heart  beneath  the  pericar- 
dium; but  whether  they  are  present  in  its  substance  and  in  the 
pericardium,  is  not  determined.  The  nerves  (from  the  pneu mo- 
gastric  and  sympathetic)  contain,  except  the  largest,  only  pale  and 
fine  fibres.  Ganglia  also  exist  in  the  substance  of  the  heart.  Dr. 
Lee,  of  London,  however,  mistook  for  ganglia  mere  thickenings  of 
the  perineuria.  {Kolliker)  How  the  nerve-fibres  terminate,  is 
unknown. 

IT.  The  Bloodvessels. 

The  bloodvessels  are  divided  into  the  arteries,  the  capillaries, 
and  the  veins. 

A.  The  Arteries. 
The  arteries^  have  three  tunics,  the  external  (cidventitia),  the  middle 
(media),  and  the  internal  (iniima).   (Fig.  332.)     Each  of  these  may, 

Fig.  332. 


Trausverse  sectiou  of  the  aorta  below  tlie  superior  mesenteric  artery.  1.  luuer  tunic.  2.  Middle 
tunic.  3.  External  tunic  (adventitia).  a.  Epithelium,  b.  Striped  lamellsc.  c.  Elastic  membrane 
of  the  inner  coat.  d.  Elastic  lamella;  of  the  middle  tunic,  e  Its  muscular  fibres  and  connectire 
tissue.  /.  Elastic  networks  of  the  external  tunic.  From  man,  treated  with  acetic  acid. — Magnified 
.'JO  diameters.  {Kblliker.) 

however,  be  subdivided,  as  will  be  seen.  In  general,  the  external 
coat  consists  of  areolar  tissue;  the  middle  of  elastic  tissue,  with 
more  or  less  smooth  muscular  fibres  admixed ;  and  the  internal  of 
an  elastic  network  (fenestrated  layer),  supporting  an  epithelium. 

1.  The  external  coat  of  the  {Isi)  larger  arteries  (above  2  or  8  lines 
in  diameter)  is  both  relatively  and  absolutely  thinner  than  in  the 
smaller — being  g  J^  to  ^J^  of  a  line — and  presents  the  same  struc- 
ture as  in  the  smaller  arteries  on  the  whole;  it  being  composed  of 


'  Meaning  "air-lioMers"  (p.  40.'J,  note)  ;  since  the  ancient  anatomists  observed 
tliat  they  usually  contained  air  after  death. 


THE   BLOODVESSELS. 


501 


areolar  tissue,  with  an  elastic  inner  layer.  In  the  {2dhj)  medium- 
sized  arteries  (|  of  a  line  to  2  or  3  lines)  this  coat  is  thicker  than 
the  middle  coat,  being  ^\^  to  ,'g  of  an  inch  thick.  It  has  an  inner 
portion,  in  the  form  of  a  laminated  elastic  membrane,  in  the  largest 
arteries  of  this  class  (brachial,  femoral,  &c.).  The  external  portions 
of  the  external  coat  also  abound  in-  elastic  fibres,  sometimes  pre- 
senting a  laminated  aspect.  Sdhj.  In  the  small  arteries  (less  than  | 
of  a  line  in  diameter),  the  external  tunic  is  merely  a  layer  of  areolar 
tissue,  as  thick  or  thicker  than  the  tunica  media.  In  arteries  ^'u  of 
a  line  or  less  in  diameter,  however,  the  outer  coat  contains  no  elas- 
tic fibres,  but  only  collagenous  tissue  and  elongated  nuclei;  and 
which,  though  still  nucleated,  at  length,  towards  the  capillaries, 
become  homogeneous,  then  a  thin  simple  membrane,  and  finally, 
in  vessels  under  jt^'j^  of  an  inch,  disappear  altogether. 


533. 


Section  of  the  aorta  of  the  ox,  showing  the  ariaugemeiit  of  the  two  layers  of  the  longitudinal 
fibrous  tunic,  and  of  the  circular  fibrous  tunic,  a  and  6,  the  inner  coat :  a,  the  epithelial  layer  ; 
6,  the  internal  portion  of  the  longitudinal  fibrous  layer  (fenestrated  membrane,  Henle).  c  and  rf, 
the  middle  coat ;  c,  the  external  coarse  stratum  of  the  longitudinal  fibrous  layer  ;  d,  a  small  portion 
of  the  circular  fibrous  tunic ;  most  of  the  fibres  are  cut  across,  but  a  few  which  take  an  oblique 
course,  are  seen  in  their  whole  length,  and  their  penniform  branching  is  slightly  indicated.  (Longi- 
tudinal section.) 

2.  The  middle  coat  of  large  arteries  (Fig.  883)  consists  of  plates  of 
elastic  tissue,  of  collagenous  tissue,  fine  elastic  networks,  and  smooth 
muscular  fibres;  the  last  constituting  only  one-fourth  to  one-third 


502 


THE   TISSUES. 


of  the  whole  tunic,  and  being  in  a  merely  embryonic  state  of  de- 
velopment. They  therefore  probably  manifest  but  little  contractile 
power.  Its  innermost  stratum,  the  annular  fibrous  layer,  contains 
the  peculiar  elastic  membranes  or  plates,  of  yooVo  to  touifo  of  ^» 
inch,  and  50  to  60  in  number,  regularly  alternating,  at  distances  of 
its'otT  to  g^o  of  ^"  inch,  with  transverse  layers  of  smooth  muscular 
fibres,  pervaded  by  areolar  tissue.  These  plates  are,  however,  not 
mere  concentric  tubes,  but  are  connected  with  each  other,  and  with 
the  firm  elastic  network  pervading  the  muscular  tissue.  (Fig.  383.) 
In  the  middle  coat  of  the  medium-sized  arteries  the  elastic  plates 
just  described  are  absent,  and  the  smooth  muscular  fibres  are  far 
more  abundant;  though  there  is  here  and  there  a  disposition  to  the 
formation  of  elastic  layers,  alternating  with  the  muscular.  Its 
muscular  fibres,  therefore,  preponderate,  and  doubtless  manifest  a 
considerable  decree  of  contractile  force.  It-  is  thinner  than  the 
external  coat. 

The  small  arteries  have  their  middle  coat  composed  exclusively 
of  smooth  muscular  fibres;  and  it  is  stronger  or  weaker,  according 
to  the  size  of  the  vessel,  down  to  ^^o  of  an  inch.  In  vessels  of 
T2TJ  to  3^(y  of  an  inch,  they  are  still  united  into  lamellae  presenting 
two  or  three  layers,  and  a  thickness  of  ^-^^-5  to  y^V^  of  an  inch,  con- 
stituting the  annular  fibrous  layer  next  the  inner  coat.  In  smaller 
vessels  it  has  but  a  single  layer  of  minute  fibres,  the  latter  becom- 
ing shorter  and  shorter  towards  the  capillaries.  In  arteries  of  toVo 
of  an  inch,  embryonic  forms  of  smooth  fibres  still  constitute  a  con- 
nected lamina  (Fig.  387,  b),  but  afterwards  they  are  gradually  sepa- 
rated from  each  other,  and  become  wholl}^  lost. 

3.  The  inner  tunic  of  all  the  arteries  consists  of  two  layers — the 
elastic  and  the  epithelial.  1.  The  elastic  {fenestrated,  Henlc)  layer 
is  merely  a  network  of  longitudinal  elastic  fibres,  resembling  the 


Fie.  334. 


V 


Fig.  335. 


Fig.  334.  Internal  or  flnoly  flbrouH  portion  of  the  longitndina!  fibrous  (fenestrated)  layer  of  the 
aorta  of  the  horse.     (Magiiifled  3)0  diameters. ) 

Fig.  33.0.  External  or  coarsely  fibrous  portion  of  the  longitudinal  lilirous  layer  of  the  aorta  of  the 
horse.     (Magnified  200  diameters  ) 


THE   BLOODVESSELS  —  ARTERIES. 


503 


clastic  lamella)  of  the  middle  coat  of  the  large  arteries.  The  elon- 
gated fissures  between  its  fibres  produce  its  fenestrated  appearance. 
(Fig.  334.)  In  the  largest  arteries  this  is  reinforced  externally  by 
a  coarsely  fibrous  layer  of  elastic  tissue,  shown  by  Fig.  335. 

1.  In  the  large  arteries  the  fenestrated  layer  is  thickened  inter- 
nally by  one  or  several  clear  layers — the  strijied  lamellce  [HenleY — 
appearing,  when  nucleated,  like  coalesced  epithelial  cells ;  and  when 
not  so,  homogeneous,  like  pale  elastic  membranes.  In  the  axillary 
and  popliteal  arteries,  smooth  muscular  fibres  have  also  been  found 
in  this  layer.  (Fig.  244.)  In  the  medium- sized  and  the  small  arteries, 
the  fenestrated  layer,  or  elastic  stratum,  is  t^^tj^  ^^  ^^  i^^^^  o^'  more 
thick,  and  smoothly  stretched  beneath  the  epithelium  during  life. 
In  collapsed  arteries  it  presents  a  number  of  strong  folds,  and 
frequently  also  fine  transverse  rugie.  It  may  be  traced  down  into 
vessels  only  -^\^  of  an  inch  in  diameter;  but  cannot  be  regarded 
as  fully  developed  in  those  less  than  -^^^  of  an  incb.  2.  The  epi- 
thelial layer  of  the  tunica  intima  consists  of  a  single  layer  of  flat- 
tened nucleated  cells.  These  in  the  large  arte- 
ries are  usually  shorter  than  in  the  smaller  ves- 
sels, though  still  fusiform,  and  j^Vt  to  x^Vo  of 
an  inch  long,  (Fig.  336.)  In  the  medium-sized 
and  small  arteries,  they  are  fusiform,  pale,  with 
long  oval  nuclei,  and  readily  separated  in  con- 
nection, in  fragments,  or  in  perfect  tubes.  The 
epithelium  may  be  traced  in  vessels  of  only 
raV^  or  even  t7T4  o^  ^^^  i^c^  ii^  diameter. 
Here,  however,  the  cells  cannot  be  isolated,  and 
its  presence  can  be  recognized  by  its  closely 
placed  elliptical  nuclei  alone. 

All  the  arteries  (and  the  veins),  above  o'^  of 
an  inch  in  diameter,  have  nutritive  vessels  (vasa 
vasorum),  derived  from  minute  contiguous  arte- 
ries, forming  a  rich  capillary  network  in  the 
external  tunic,  and  which  extend  into  the  outer  portion  of  the  mid- 
dle coat  of  the  large  vessels,  but  not  to  its  inner  portion,  nor  to 
the  inner  coat  at  all.  Nerves  also,  both  sympathetic  and  spinal,  are 
distributed   to   many  arteries,   but  often    only   accompany   them. 


Fig.  336. 


Epithelial  cells  from  the 
aorta  of  an  ox.  (Magnified 
400  diameters.) 


'  In  the  large  vessels  the  striped  lamellse  are  sometimes  not  covered  bv,  but  are 
continuous  with,  the  epithelium. 


50i 


THE    TISSUES. 


"When  they  enter  the  artery  they  cannot  be  traced  beyond  the  outer 
coat.  Many  arteries  are,  however,  without  nerves ;  e.  g.  those  of 
the  cerebral  and  spinal  substance,  of  the  choroid  plexus  and  the 
placenta,  as  well  as  many  arteries  of  muscles,  glands,  and  mem- 
branes. Of  the  veins^  it  is  only  in  the  larger  that  a  few  fine  nerves 
can  be  demonstrated,  e.  g.  the  sinuses  of  the  dura  mater,  the  verte- 
bral canal,  the  venae  cavae,  and  the  jugular,  iliac,  femoral,  and  he- 
patic veins.  These  also  are  both  spinal  and  sympathetic.  Luschka 
thinks  they  terminate  in  the  inner  coat — a  point  not  yet  decided. 

B.  The  Capillaries. 

The  arteries  terminate  in  the  capillaries — vessels  always  inter- 
vening between  the  former  and  the  veins;  except  in  case  of  the 
corpora  cavernosa  penis,  and  of  the  placenta.  {Kolliker.) 

The  capillaries  are  everywhere  composed  of  a  single  layer  of 
simple  membrane  with  nuclei;  the  structural  transitions  of  the 
small  arteries  into  these  vessels  being  wholly  imperceptible.  (Fig. 
337,  B.) 

On  minute  examination,  the  structureless  membrane  is  sometimes 
transparent,  and  with  a  simple  contour;  at  others,  thicker  (xg^ou 

Fig.  337. 


A.  A  capillary  vessol  from  the  gray  matter  of  tho  hnman  brain  ;  a,  wall,  of  simple  membraue  ;  b, 
nucleus  of  the  wall  ;  c,  red  blood-corpuscles,  b,  c.  Different  appearances  of  small  arteries  and 
veins  of  the  human  pia-mater;  a,  a,  simple  membrane;  b,  b,  circular  fibres;  c,  c,  oval  nuclei  of  the 
internal  epithelium  here  about  to  cease  ;  d,  d,  transverse  indications  of  the  circular  fibres,  d.  Ter- 
minal artery  from  the  mesentery  of  a  rabbit.     (Magnified  200  diameters.) 


TUE    BLOODVESSELS  —  C AJ'I  LLAKIES.  505 

to  i-yasTy  of  an  inch),  and  bordered  by  a  double  line.  It  corresponds 
chemically  with  the  myolemma  of  the  striated  muscular  fibres;  is 
perfectly  smooth  on  both  sides,  and  tolerably  resistant  and  elastic, 
though  probably  not  contractile.  [KUlUker)  The  nuclei  are  elon- 
gated, 40V0  to  -j/oo  of  an  inch  in  diameter,  and  usually  alternate 
on  opposite  sides  of  the  vessel,  though  rarely  in  contact  with  each 
other.  When  the  capillary  wall  is  thick  they  are  lodged  in  its 
substance,  though  sometimes  projecting  externally ;  when  thinner, 
they  are  situated  on  its  inner  side.  (Fig.  337.)  Their  diameter 
varies  from  g^Vxr  to  ^^^is  of  an  inch. 

The  union  of  the  capillaries  constitutes  a  cci'pillary  plex7xs,  already 
described,  in  connection  with  the  different  tissues  and  organs.  As 
the  histological  elements  of  the  various  tissues  are  not  themselves 
penetrated  by  capillaries,  but  the  latter  are  merely  distributed 
among  the  former,  the  capillary  plexus  of  each  tissue  and  organ 
will  assume  a  form  more  or  less  peculiar.  Generally,  indeed,  a  tissue 
or  organ  may  be  at  once  recognized  by  its  capillary  network  alone. 
It  is  closest  in  the  secreting  organs  (especially  the  liver,  lungs, 
and  kidneys)  (Figs.  406,  375);  next  in  the  skin,  and  mucous  mem- 
branes (Figs.  322  and  353);  and  is  much  wider  in  organs  receiving 
blood  only  for  their  own  nutrition,  as  the  muscles,  nerves,  organs 
of  sense,  serous  membranes,  tendons,  and  bones.  (Figs.  266,  176,  &c.) 
The  muscles  and  the  gray  nerve-substance  are,  however,  more 
abundantly  supplied  than  the  other  parts  just  mentioned.  Their 
diameter  also  varies  directly  with  the  closeness  of  the  plexus;  it 
being  goVo  to  joVo  o^  ^^  i^^ch  in  the  glands,  ^-^joo  to  24V0  ^'^  the 
skin  and  mucous  membranes,  and  thinnest  and  smallest  (goVo  to 
4  (jVt5-  of  an  inch)  in  the  nerves,  muscles,  retina,  and  the  patches  of 
Peyer.  In  the  compact  bone  structure,  however,  though  no  longer 
having,  in  all  respects,  the  structure  of  capillaries,  they  attain  to 
the  diameter  of  ygio  to  ygVo  of  an  inch  (p.  337,  2). 

On  tracing  the  capillaries  towards  the  arteries,  the  nuclei  become 
more  closely  placed,  and  a  structureless  tunica  adventiiia,  and  soli- 
tary muscular  cells,  appear  externally;  and  becoming  tt'tt  of  an 
inch  in  diameter,  they  exhibit  the  aspect  of  the  finest  arteries. 
Afterwards  the  nuclei  seem  to  be  replaced  by  epithelium,  and  the 
membrane  of  the  capillary  either  ceases,  or  is  continuous  with  the 
fenestrated  layer  of  the  artery.    (Fig.  337,  B.) 

The  capillaries  merge  in  the  opposite  direction  into  the  veins  by 
less  characteristic  changes.     On  this  side  an  external  nucleated 


506  *  THE   TISSUES. 

layer  is  first  added  to  the  capillary  membrane,  and  wliicli  gradually 
combines  with  the  latter,  while  the  nuclei  of  the  capillaries  become 
more  closely  approximated.  In  vessels  of  ij'oo  of  ^^  inch,  they 
have  become  so  numerous  as  clearly  to  represent  the  epithelium, 
and  now  the  external  layer  has  received  also  the  addition  of  a  nu- 
cleated lamina,  the  tunica  adventitia,  and  the  vessel  has  become  a 
vein.     (Fig.  337,  c.) 

The  older  anatomists  have  also  assumed  the  existence  of  still 
finer  vessels  than  the  capillaries,  never  admitting  the  blood-corpus- 
cles, called  vasa  serosa;  and  recently  Hyrtl  has  admitted  their  ex- 
istence in  the  cornea.  If  any  such  vessels  exist  in  the  cornea,  they 
must  be  regarded  as  atrophied  capillaries;  the  latter  having  formed 
an  abundant  plexus  in  the  foetus.  It  cannot  be  admitted  that  such 
vessels  exist  in  the  adult  in  any  other  part,  at  any  rate  (p.  281). 
The  finest  capillaries  above-mentioned  have  a  less  diameter  than 
the  smallest  blood-corpuscles;  but  the  latter  easily  adapt  themselves 
by  thair  extensibility  and  elasticity  to  traverse  the  former. 

c.  The  Veins. 

The  veins  also  present  three  tunics — the  adventitia  (external),  the 
media,  and  the  intima ;  and  may  also  be  divided  into  the  small,  the 
medium-sized,  and  the  large.  Their  walls  are  always  thinner  than 
those  of  the  arteries,  there  being  less  of  both  the  muscular  and 
the  elastic  element.  The  external  coat  is  usually  the  thickest  of 
the  three ;  its  relative  and  absolute  thickness  usually  increasing 
with  the  size  of  the  vessel.  The  inner  coat  is  often  not  thicker  in 
large  veins  than  in  those  of  medium  size. 

1.  The  smallest  veins  may  be  said  to  consist  of  a  nucleated  indis- 
tinctly fibrous  or  homogeneous  areolar  tissue,  lined  by  a  scaly 
epithelium.  A  muscular  Tnemhrane,  and  generally  a  layer  of  an- 
nular fibres  are  first  seen  in  veins  above  g  J^g  of  an  inch  in  diameter; 
the  contractile  cells  being  at  first  oval,  placed  transversely  (Fig. 
337,  c),  and  widely  apart,  but  which  afterwards  become  longer  and 
more  numerous;  and,  finally,  in  vessels  of  y.^jsv  ^ip  to  x^tt  of  ^^ 
inch,  constituting  a  continuous  layer,  but  always  less  developed  than 
the  middle  coat  of  the  small  arteries.  Afterwards,  elastic  networks 
gradually  make  their  appearance  in  this  muscular  layer,  and  in  the 
external  coat;  the  muscular  layers  also  multiplying,  and  admitting 
areolar  tissue  among  their  elements. 


TOE    BLOODVESSELS  —VEINS. 


507 


Fig.  338. 


Tninsverse  section  of  tlio 
vena  saphena  magna  at  the 
malleolus,  a.  Striped  lamella; 
and  epithelium  of  the  tunica 

intima.  h.  Its  elastic  mem- 
lirane.  c.  Longitudinal  in- 
ternal connective-tissue  layer 


elastic  network  disposed  in  a 
laminated  manner.  /.  Tunica 
adventitia. — Blagnified  30  dia- 
meters. (KiJlliker.) 


2.  The  viedmm-s'ized  veins  (1  to  o  lines  in  diameter)  have  an  ex- 
fcrnal  tunic  almost  always  tliicker  than  the 
middle  coat,  of'ton  twice  as  thick,  though  rare- 
ly as  strong.  It  is  composed  of  areolar  tissue, 
except  in  some  visceral  veins  whose  trunks 
contain  longitudinal  muscular  fibres,  and  into 
whose  bi-anches  also  the  muscular  elements 
extend  for  some  distance. — The  middle  coat 
has  a  considerable  development  of  the  annular 
fibrous  lajjer^  of  a  yellowish-red  color,  as  in  the 
arteries.  It,  however,  is  never  more  than  ^i^ 
to  -Y^x  of  an  inch  thick.  Unlike  that  of  the 
arteries,  it  consists  of  longitudinal  as  well  as 
transverse  layers.     (Fig.  338.)  ,.,   .    .        ,.      .^,   , 

■^  \       o  /  of  the  tunica  media,  with  elas- 

The    latter    are     composed    of     undeveloped     tic  tlbres.  d.  Transverse  mus- 

1  .  ■  11  J.      r"  ii       cular  layer,     e.  Longitudinal 

areolar  tissue  and  a  large  amount  oi  smooth 
muscular  fibres.  In  the  popliteal,  saphena 
major  and  minor,  and  the  profunda  femoris 
vein,  there  is  a  transverse  layer  of  muscular 

fibres  Avith  areolar  tissue,  immediately  in  contact  with  the  tunica 
intima,  external  to  which  is  a  regular  alternation  of  longitudinal 
elastic  membranes  and  transverse  muscular  fibres;  so  that  the  mid- 
dle coat  presents  a  laminated  aspect  somewhat  like  that  of  the 
largest  arteries.  There  are  from  five  to  ten  of  these  elastic  lamina ; 
their  interspaces  being  from  -g^ViT  to  T-i'oo  of  an  inch. — -The  inner 
coat  of  the  medium-sized  veins  is  tAo  to  ^^^  of  an  inch  thick. 
"Where  it  is  thinnest,  it  consists  of  an  elastic  longitudinal  mem- 
brane, corresponding  to  the  fenestrated  membrane  of  the  arteries, 
and  a  striated  nucleated  lamella  within  it,  and  an  epithelium  with 
shorter,  though  elongated  cells.  When  the  tunica  intima  is  thicker, 
the  striated  lamelhe  are  multiplied,  and  one  or  sjverai  additional 
networks  of  fine  elastic  fibres  appear  on  the  inner  surface  of  the  lat- 
ter, forming  the  limitary  portion  of  the  inner  coat.  Muscular  fibres 
also  have  been  seen  in  the  inner  coat  of  the  veins  of  tho  gravid 
uterus,  in  the  saphena  major,  and  the  popliteal  vein.  (Kdlliker.) 

3.  In  the  largest  veins  the  exter7ial  coat  is  almost  invariably  nearly 
twice  as  thick  as  the  middle,  and  sometimes  five  times  as  thick,  and 
also  contains  a  considerable  amount  of  longitudinal  smooth  muscu- 
lar fibres.  (Fig.  243.)  These  are  very  distinct  in  the  hepatic  portion 
of  the  inferior  vena  cava  {Bernard),  constituting  a  network  pervading 


503  THE    TISSUES. 

the  inner  lialf,  or  two-thirds  of  the  external  coat,  which  rests  upon  the 
tunica  intima  directly,  and  may  become  g^g  of  an  inch  thick.  Kol- 
liker  found  these  longitudinal  bundles  extending  through  the  entire 
thickness  of  the  external  coat  in  the  renal  veins  and  the  vena  portae ; 
and  very  well  developed  also  in  the  trunks  of  the  hepatic  veins, 
the  remaining  portions  of  the  vena  cav«,  and  to  the  splenic,  supe- 
rior mesenteric,  and  external  iliac  veins.  All  the  large  veins  open- 
ing into  the  heart,  are  furnished  for  a  short  distance  also  with  an 
external  annular  layer  of  striated  muscular  fibres^  like  those  of  the 
heart  itself,  and  some  of  them  also  presenting  anastomoses.  They 
extend  in  the  superior  vena  cava?  to  the  subclavian  vein;  and  may 
be  found  in  the  main  branches  of  the  pulnionary  veins.  (Bduschel.) 

The  tunica  media  of  the  large  veins  is  sparingly  developed,  and 
especially  its  muscular  elements,  which  are,  however,  often  abund- 
ant in  the  external  coat,  as  has  just  been  stated.  It  is  usually  g^^ 
to  -gf^  of  an  inch  thick;  but  may  be  j^o  to  ^Ao  of  an  inch  (at  the 
orifices  of  the  hepatic  veins),  or  may  be  wholly  wanting;  as  in  the 
greater  part  of  the  vena  cava  in  the  liver,  and  the  trunks  of  the 
hepatic  veins.  Its  longitudinal  elastic  networks  are  intimately  con- 
nected together,  and  less  distinctly  laminated  than  in  the  medium- 
sized  veins,  or  not  at  all  so.  The  transverse  muscular  fibres  are 
also  scanty  and  less  distinct;  being  most  developed  in  the  splenic 
vein  and  vena  portas.  The  tunica  intima  is  usually  ygVu  of  an  inch, 
when  it  presents  the  same  conditions  as  in  the  medium-sized  veins. 
Rarely,  as  in  the  vena  cava  inferior,  the  trunk  of  the  hepatic,  and 
in  the  vena  innominata,  it  is  g^^  to  ^^^  of  an  inch  thick;  this  in- 
crease of  thickness  being  due  to  striped  lamelloi  with  nuclei,  and 
fine  elastic  longitudinal  networks,  and  never  to  lamella)  composed 
of  muscular  fibres. 

In  the  veins  of  the  gravid  uterus  the  muscular  element  is  exclu- 
sivehj  developed;  it  existing  in  all  three  of  their  tunics.  It  is  en- 
tirely wanting^  1,  in  the  veins  of  the  maternal  portion  of  the  pla- 
centa; 2,  in  most  of  the  veins  of  the  cerebral  substance  and  of  the 
pia  mater;  3,  in  the  sinuses  of  the  dura  mater,  and  the  veins  of 
Breschct  in  the  bones  (which  have  merely  a  layer  of  collagenous 
tissue  external  to  a  scaly  epithelium);  4,  in  the  sinuses  of  the  cor- 
pora cavernosa;  and  5,  in  the  veins  of  the  retina. 

The  valves  of  the  veins  are  projections  of  the  middle  and  internal 
tunics.  Muscular  fibres  have  been  found  by  Wahlgren  in  the 
larger  valves. 


LYMi'HATIC    VESSELS   AND    GLANDS. 


509 


in.  The  Lymphatic  Vessels  and  Glands. 

The  lymphatic  vessels  correspond  so  closely  in  structure  with 
the  small  veins,  as  to  require  but  a  brief  description. 

The  finest  {capillary)  lymphatics  have  been  seen  with  certainty 
only  in  the  small  intestine,  the  mucous  membrane  of  the  trachea, 
and  the  tail  of  the  tadpole.  They  have  a  wall  of  simple  membrane 
without  distinct  nuclei,  and  a  diameter  of  ^Ari  to  To'nTi  of  an  inch. 


T20U 


(E'ig.  339.)     How  these  are  changed  into  the  larger  lymphatic  ves- 
sels (Fig.  341,  B  and  c),  is  unknown.     Of  the  latter,  the  smallest 

Fig.  339. 


Capilliiry  lymphatic  from  the  tail  of  the  tadpole,  a.  Simple  membrane,  b.  Process  formed  by  it. 
c.  Eemains  of  the  contents  of  the  cell  forming  these  vessels,  in  which  nuclei  are  concealed,  d.  Gra- 
nules, forming  lymph-corpuscles,  e.  Coecal  termination  of  the  vessels.  /.  One  of  the  terminations, 
still  pretty  distinctly  recognizable  as  a  formative  cell.  g.  Isolated  formative  cells  about  to  join 
with  the  actual  vessels.  (KCUiker.) 


are  xlir  to  t^'j  of  an  inch,  the  larger  1  to  1|  lines.  The  last  present 
3  coats.  The  external  coat  contains  longitudinal  smooth  muscular 
fasciculi.  The  middle  coat  is  composed  of  transverse  muscular, 
and  fine  elastic  fibres.  The  tunica  intima  consists  of  a  single,  and 
rarely  double,  elastic  reticulated  membrane,  and  an  epithelium  of 
elongated,  though  still  rather  short,  cells.     (Fig.  142.) 

The  thoracic  duct  has  striped  lamellas  between  the  epithelium  and 
the  elastic  reticulated  membrane,  though  the  whole  inner  coat 
scarcely  measures  ^^Vo  to  tAtt  ^^  ^^  inch.  The  middle  coat  (^^^ 
of  an  inch  thick)  contains  a  transverse  muscular  layer  and  areolar 


510 


THE    TISSUES. 


340. 


tissue.     (Fig.  340.)     The  outer  coat  is  composed  of  areolar  tissue 
and  longitudinal  fasciculi  of  smooth  muscular  fibres. 

The  valves  of  the  duct,  and  of  the  lym- 
phatics generally,  correspond  with  those 
of  the  veins.  The  vessels  present  the  same 
conditions  in  the  duct,  as  those  of  the 
veins.  No  nerves  have  yet  been  found  in 
the  lymphatics. 

The  lymiihalic  glands  present  a  thin,  fine 
sheath  of  areolar  tissue  inclosing  a  soft 
whitish-red  parenchyma,  in  which  a  fi- 
brous portion,  a  soft  pulp,  and  bloodves- 
sels are  seen.  1.  The  fibrous  poition  is 
areolar  tissue  proceeding  from  the  sheath, 
and  taking  the  form  of  many  lamellaj;  it 
constitutes  an  eleo-ant  areolated  structure 


d  5  c 


Transverse  sectiou  of  the  hu- 
man thoracic  duct.  a.  Epithe- 
lium, striped  lamellae,  and  elastic 
inner  membrane.  6.  Longitudi- 
nal connective-tissue  of  the  tunica 
media,  c.  Transverse  muscles  of 
the  same  tunic,  d.  Tunica  ad  ven- 
titla,  with  e,  the  longitudinal  mus- 
cles.—  Magnified  30  diameters. 
{Krlliker.) 


Fis.  341. 


A.  One  of  llio  itu'iiinal  lymphatic  glands  injected  with  mercury  ;  a,  afTorcut  lymphatic  ve.ssols 
from  the  lower  exlromity  ;  b,  etfereut  vessel — others  are  also  seen.  B.  Cue  of  the  superficial  lym- 
phatic trunks  of  the  thigh,  o.  One  of  the  femoral  lymphatic  trunks  laid  open  longitudinally  to 
display  the  valves  within  it;  c,  sinus  between  the  valves  and  the  wall  of  the  vessel,  d.  Surface 
of  one  valve  directed  towards  the  opposite;  e,  semicircular  attached  margin  of  the  valve,  d.  Sec- 
lion  of  lymphatic  gland,  showing  a  n,  the  fibrous  tissue  which  forms  its  exterior;  bb,  superficial 
vasa  alfurentia  ;  c  c,  larger  alveoli  near  the  surface  ;  d  d,  smaller  alveoli  of  the  interior ;  e  e,  fibrous 
walls  of  the  alvo.ili.     (AfUr  Munrngtii.) 


devp::lopmext  of  the  vasculak  system.         511 

pervading  the  entire  gland,  all  of  whose  rounded  spaces,  ^'^  to  -j'g 
of  an  inch  wide,  conamunicate  freely.  2.  The  grayish-white  alka- 
line pulp  filling  them,  agrees,  in  almost  all  respects,  with  that  in  the 
follicles  of  Peyer.  (Fig.  360).  3.  Vessels  also  enter  these  spaces 
and  form  a  fine  vascular  network  as  in  the  follicles  just  mentioned. 
(Fig.  341,  A.) 

The  lymphatic  glands  are,  therefore,  not  mere  convolutions  of 
the  lymphatic  vessels;  but  distinct  and  independent  structures,  in 
the  areolae  [alveoli,  Kolliker)  of  which  the  vasa  afferentia  terminate, 
and  the  efferentia  commence.  The  cells  contained  in  the  pulp 
seem  identical  with  the  lymph-  (cytoid)  corpuscles  of  the  blood ;  and 
a  portion  of  the  latter  may,  perhaps,  be  developed  here.  The  vasa 
afferentia  lose  their  muscular  layer  as  they  enter  the  gland,  and 
enter  the  alveoli  with  only  a  layer  of  areolar  tissue  and  an  epithe- 
lium. Nervous  filaments  composed  of  fine  fibres  enter  the  glands 
with  the  vessels,  and  disappear  in  their  interior. 

The  most  common  degeneration  of  the  lymphatic  glands  is  pro- 
duced by  the  extravasation  of  blood  into  the  alveoli,  leading  to 
deposits  of  quite  dark  pigmentary  matter  (as  in  the  bronchial 
glands).  The  sheaths,  or  internal  septa,  are  also  liable  to  become 
thickened,  and  fatty  deposits  to  occur  in  the  bloodvessels.  Hyper- 
trophy of  all  their  elements  may  also  occur,  and  tuberculous  and 
cancerous  deposits. 

Functions  of  the  Vascular  System. 
For  the  precise  role  of  each  part  of  the  blood- vascular  system  in 
securing  the  circulation  of  the  blood,  and  for  the  action  of  the 
lymphatics,  reference  must  be  had  to  the  works  on  physiology. 
The  blood  and  lymph  (and  chyle)  have  already  been  described  at 
length  (p.  147-79). 

Development  of  the  Vascular  System. 
1.  The  rudiments  of  the  heart,  arteries,  and  veins  are  alike  solid 
tracts  of  cells,  of  greater  or  less  thickness;  which,  by  a  liquefaction 
internally,  and  a  transformation  of  the  central  cells  into  blood-cor- 
puscles, become  cavities  and  continuous  passages  for  the  blood. 
The  heart  manifests  contractions  while  still  in  the  form  of  a  cellular 
tube;  and  subsequently  the  cells  occupying  the  walls  elongate  into 
the  muscular  and  other  fibres.  At  the  same  time,  the  vessels  be- 
come thicker,  and  increase  in  circumference,  at  first  by  an  augmen- 
tation of  the  number  of  the  cells;  ai'terwards  chiefly,  if  not  solely. 


512 


THE    TISSUES. 


Fie.  342. 


by  their  growth  in  length  and  thickness.  In  the  fifth  month  of 
foetal  life,  all  the  larger  and  medium-sized  vessels  are  formed  with 
their  coats  and  tissues,  and  no  vestige  of  the  formative  cells  remains. 
The  tissues  are,  however,  still  incomplete,  the  muscular  fibres  being- 
short  and  delicate,  and  there  being  only  layers  of  slightly  coalescent 
fusiform  cells,  instead  of  the  elastic  membranes  subsequently  to 
appear. 

2.  The  capillaries  are  developed  in  an  entirely  different  manner 
from  the  preceding,  since  they  are  formed  by  the  coalescence  of  single 

cells.  These  are  first  arranged  in 
a  line,  then  the  contiguous  cell- 
walls  are  absorbed,  with  their  con- 
tents, but  not  their  nuclei,  which 
still  appear,  therefore,  in  the  wall 
of  the  capillary  vessel.  Delicate 
pointed  processes  then  project  from 
the  walls  of  these  little  vessels, 
which  rapidly  elongate,  and  coa- 
lesce with  similar  processes  of  stel- 
late cells  dispersed  in  the  surround- 
ing tissue.  The  other  processes  of 
these  stellate  cells  also  unite,  and 
thus  a  network  of  stellate  cells, 
continuous  with  the  already  formed 
capillaries,  is  produced.  The  pass- 
ages in  this  network  are  at  first 
very  minute  and  irregular,  and  do 
not  admit  the  blood-corpuscles; 
but  they  rapidly  enlarge,  and  be- 
come true  capillaries.  (Fig,  8-i2.) 
New  connections  are  also  frequent- 
ly formed  between  already  pervious 
capillaries,  by  the  direct  meeting  of 
prolongations  from  them,  and  by 
the  mutual  connection  of  forma- 
tive cells  lodged  in  their  interstices. 
8.  The  aqyillary  lymphatics  exhi- 
bit essentially  the  mode  of  develop- 
ment just  described;  except  that 
anastomoses  are  rare  in  them,  and 


Formation  of  capillaries  in  tail  of  tatlpolo. 
a, a.  Capillaries  perriioable  to  blood.  6,6.  Fat- 
granules  attached  to  the  walls  of  the  ves.sels, 
and  concealing  the  nuclei,  c.  Hollow  pro- 
longation of  a  capillary  ending  in  a  point,  d. 
A  branching  coll  with  nucleus  and  fat-gran- 
nle«,  communicating  by  tlirce  brandies  with 
capillaries  alrcjidy  lormed.  c.  Ulood-corpus- 
cles  still  containing  granules  of  fat. 


PATHOLOGICAL   STATES    OF   THE    VESSELS. 


513 


Fig.  343. 


its  course  is  limited  to  the  rnutaal  apposition  of  fusiform  cells,  or 
of  those  furnished  with  three  principal  processes. 

Pathological  Conditions  and  New  Formations  of  the  Vessels. 

The  larger  arteries  are  liable — 1.  To  atheromatous  deposits  (p.  312); 
these  occurring  in  the  annular  fibrous  layer  (i.  e.  next  external  to 
the  fenestrated).  (Figs.  198  and  199.)  It  appears  to  be  due  to  im- 
jierfect  nutrition  by  the  vasa  vasorum  ( Wedl\  and  is  therefore  one 
form  of  atrophy.  The  arterial  wall  becomes  weaker  in  proportion 
to  the  accumulation  of  the  fat;  and,  becoming  dilated,  an  anenrism 
is  ver}^  often  produced.  2.  By  the  collapse  of  their  walls  (as  by 
pressure,  ligature,  &c.),  the  arteries  become  transformed  into  liga- 
mentous cords,  and  finally  into  mere  fibrils  of  collagenous  tissue, 
covered  with  a  finely  granular  substance. 

3.  The  veins  undergo  essentially  the  same  changes  in  atrophy, 
and  varix  is  the  consequence.    The  depo- 
sit is  usually  a  finely  granular  pigment- 
substance.      This  change  also  occurs  in 
their  valves. 

4:.  The  capillaries  are  liable  to  a  fiitty 
degeneration  of  their  walls ;  fatty  gran- 
ules and  minute  oil-drops  being  deposit- 
ed in  them,  especially  around  the  nuclei. 
(Fig.  3-13.)  The  minute  arteries  also  un- 
dergo a  similar  change,  especially  in  the 
brain  of  apoplectic  persons ;  and  which 
leads  to  rupture,  and  the  hemorrhage  in 
which  the  apoplexy  consists. 

5.  Pathological  new  formations  of  vessels 
occur  in  two  ways:  1st,  by  extension  from 
pre-existing  vessels;  and,  2dhj,  by  inde- 
])endent  development  in  exudations  un- 
dergoing organization.    In  the  latter  case,      ,,  *.   ^  <■      <•    ■    . 

,      o         °        O  ?         Fatty  degeneration  of  minute  ar- 

tne  processes  Oi  various  stellate  cells  meet,      teries  and  capUlaries  of  the  brain. 

the  dissepiments  are  absorbed,  and  a  net-    mwhite  softening.   Numerous  mi- 

WOrk  of  vessels  is  produced,  of  unequal  '^»te°il-glo1>"les  are  seen  aggregated 
-, .  .  .  \  -*■  „  along  their  -n-alls. 

dimensions,  since  the  processes  are  lar 

slenderer  than  the  bodies  of  the  cells.  Finally,  however,  the  diame- 
ter becomes  uniform  throughout  the  plexus,  and  is  usually  greater 
than  that  of  the  capillaries  of  normal  tissue.  Subsequent!}^,  also, 
blood-corpuscles  are  developed  in  the  plasma  contained  in  the  new- 
formed  vessels;  but  which  cannot  pass  into  the  general  circulation 
till  a  communication  is  established  with  it  by  them. 


38 


514  THE   TISSUES. 


CHAPTER    XIII. 

STRUCTUKE    OF   THE   ALIMENTARY    CANAL   AND   ITS 
APPENDAGES. 

The  alimentary  canal  is  a  tube  commencing  witli  the  mouth,  or 
oral  cavity,  and  ending  at  the  anus.  It  is  divided  into — 1st,  the 
supra-diaphragmatic  portion,  consisting  of  the  oral  cavity,  the  pha- 
rynx, and  the  oesophagus;  and,  2dhj,  the  infra-diaphragmatic  por- 
tion, including  the  stomach,  small  intestine,  and  large  intestine. 
Underneath  the  mucous  membrane  is,  in  most  parts,  a  layer  of  sub- 
mucous areolar  tissue;  and  externally  to  this,  two  layers  of  smooth 
muscular  fibres;  except  in  the  oral  cavity,  the  pharynx,  and  the 
upper  portion  of  the  oesophagus,  where  striated  fibres  are  found 
instead  of  the  former.  The  external  layers  (areolar  and  muscular) 
present  no  peculiarities  of  structure,  except  such  as  will  be  men- 
tioned in  connection  with  that  of  the  mucous  membrane  of  the 
several  portions  just  mentioned.  But  the  latter  presents  marked 
variations  in  its  difi'erent  portions,  and  will  be  particularly  described. 
The  appendages  to  be  described  in  this  chapter  are  the  liver  and  the 
pancreas.  The  spleen  will  be  described  in  the  chapter  upon  the 
blood-vascular  glands. 

1.  Mucous  Membrane  of  the  Oral  Cavity. 

The  epithelium  of  the  oral  mucous  membrane  is  of  the  com- 
pound scaly  variety,  and  is  continuous  with  the  cuticle  and  stratum 
Malpighii  of  the  skin  at  the  margins  of  the  lips.  It  is  not,  how- 
ever, distinctly  divisible  into  the  two  layers  just  mentioned;  but 
resembles  the  stratum  Malpighii  of  the  skin,  with  the  undermost 
laminte  of  the  cuticle.  It  undergoes  certain  modifications  upon  the 
papilla}  of  the  tongue,  hereafter  to  be  described.  Unlike  the  cuticle, 
the  oral  epithelium  is  easily  permeated  by  fluids;  and  also  from 
within  outwards,  by  plasma  passing  from  the  vessels  of  the  mucous 
membrane  into  the  mouth. 

The  corium  of  the  oral  mucous  membrane,  though  continuous 


MUCOUS    MEMHIIAXE    OF   THE    ORAL    CAVITY.  515 

with  that  of  the  skin  at  the  border  of  the  lips,  is  more  transpa- 
rent, soft,  and  extensible,  but  possesses  considerable  firmness.  It 
consists,  like  the  thinnest  portions  of  the  latter,  of  a  single  layer, 
formed  of  collagenous  tissue  with  elastic  fibres;  presenting  a  great 
number  of  papilla3,  like  those  of  the  skin,  on  its  outer  surface — 
generally  simple,  but  sometimes  double,  or  even  multiple,  and 
standing  so  close  together  that  their  bases  are  nearly  in  contact, 
and  rarely  more  than  their  own  breadth  apart.  They  average  jig 
to  g'g  of  an  inch  in  length,  and  gj^  to  -gj^  of  an  inch  in  breadth. 
They  consist  of  a  slightly  granular  homogeneous  substance. 

The  papillas  upon  the  upper  surface  of  the  tongue  demand  a 
particular  description.  The  corium  is  also  here  attached  directly 
and  closely  to  the  subjacent  muscular  tissue,  by  a  dense  layer  of 
collagenous  tissue.  The  lingual  papillre  are  of  three  kinds:  the 
papilla3  circumvaUatce,  the  fungiformeSj  and  the  JUiformes,  or  conicce. 
All  these  project  freely;  but  there  are  also  other  smaller  ones,  com- 
pletely buried  in  the  epithelium,  over  the  whole  gustatory  region 
of  the  tongue. 

1.  The  2M2nlIce  filiformes,  or  conicce,  are  crowded  between  the  fungi- 
formes,  and  are  most  abundant  on  the  middle  of  the  tongue.  They 
are  conical  processes,  -g'g  to  -^  of  an  inch  long,  by  j-oo  to  gV  broad, 
of  the  corium  of  the  mucous  membrane,  divided  at  their  extremi- 
ties into  from  five  to  twent}^  smaller  secondary  papillte,  of  yi^  to 
g'g  of  an  inch.  These  are  covered  by  a  thick  epithelial  coat,  drawn 
out  into  a  number  of  long,  thin,  fine,  and  subdivided  processes, 
resembling  a  fine  brush,  and  sometimes  i}^  to  -^^  of  an  inch  long. 
The  whole  mass  somewhat  resembles  a  hair  (Fig.  84-i),  and  is  liable 
to  be  covered  with  mucedinous  fungi.  (Fig.  155.)  Each  filiform 
papilla  has  an  artery  giving  a  capillary  loop  to  each  of  the  simple 
papillae  upon  it.  Nerves  also  can  be  found  in  most,  but  not  all,  of 
them;  there  being  in  the  base  of  the  papilla  one  or  two  small 
trunks  with  five  to  ten  dark-bordered  nerve-fibres,  becoming  finer 
as  they  approach  the  point.  They  probably  terminate  in  loops, 
{KoUa-er.)     (Fig.  345.) 

2.  The  fungiform  2yaptllce  abound  particularly  on  the  anterior  part 
of  the  tongue.  They  consist  of  a  clavate  primarj'  papilla,  ^'^  to  ,'5 
of  an  inch  long,  to  g'o  to  ^'4  of  an  inch  broad,  covered  with  closely 
placed,  conical,  secondary  papillae,  yi^  to  y^^  of  an  inch  long,  and 
covered  by  a  simple  epithelium,  only  g-^'g^  to  24V1.-  of  an  inch  thick, 
over  their  points.     (Fig.  346.)     The  vessels  are  arranged  as  in  the 


516 


THE   TISSUES. 
Fig.  344. 


/////////.  I  //  / , /J.    '■'i'/"i'/'m/M//////w/////, 

a    I    A.  c      d 

A.  Vertical  section  near  the  middle  of  the  dorsal  surface  of  the  tongue  :  a,  a,  fungiform  papillie  ; 
h,  filiform  papillae,  with  their  hair-like  processes  ;  c,  similar  ones,  deprived  of  their  epithelium. 
(Magnified  2  diameters),  b.  Filiform  papilla; :  n,  artery  ;  «,  vein  ;  e,  capillary  loops  of  the  secondary 
papilla;;  b,  line  of  basement-membrane;  d,  secondary  papillae,  deprived  of  their  (e,e)  epithelium; 
/,  hair-like  processes  like  epithelium,  capping  the  simple  papillre  (magnified  25  diameters) ;  g,  sepa- 
rated nucleated  particles  of  epithelium  (maguiHed  300  diameters).  1,  2.  Hairs  found  on  the  surface 
of  the  tongue.  3,  4,  .^.  Ends  of  hair-like  epithelium  process,  sliowing  varieties  in  the  imbricated 
arrangement  of  the  particles,  but  in  all  a  coalescence  of  the  particles  towards  the  point.  5.  Incloses 
a  soft  hair.     (Magnified  160  diameters.) 

papillas  filiforraes,  except  that  they  are  far  more  numerous.  (Fig. 
846,  B.)  One  or  two  larger  nervous  trunks  also  (3  oVtt  to  y^Vo  of  ^" 
inch)  enter  every  fungiform  papilla,  besides  many  minute  filaments, 
which,  repeatedly  anastomosing,  spread  out  like  a  brush  towards 
the  secondary  papilla?  and  their  axile  corpuscles.  They  probably 
terminate  both  in  loops  and  in  free  extremities.  [Kolliker.) 

3.  The  papillce,  circumvallaice  are  situated  at  the  base  of  the  tongue, 
are  six  to  twelve  in  number,  and  consist  of  a  central  round  papilla, 
flattened  at  the  end,  ^'^  to  -,'2  of  an  inch  in  diameter,  and  ^j'g  to  even 
j*3  of  an  inch  high ;  with  a  lower  uniform  wall,  g^^  to  ^\  of  an  inch 


MUCOUS   MEMBRANE   OF   THE   OliAL   CAVITY. 
Fig.  345. 


517 


A.  Secondary  papilla  of  the  conical  class  treated  with  acetic  acid  :  a,  its  basement-memhrane  :  h, 
its  nerve-tube,  forming  a  loop  ;  c,  its  curly  elastic  tissue.  The  epithelium  in  this  instance  is  not 
abundant,  but  the  vertical  arrangement  of  its  particles  over  the  apex  of  the  papilla  is  vrell  seen  («i), 
and  illustrates  the  mode  of  formation  of  the  hair-like  processes  described  in  the  text.  (Magnified 
160  diameters.)  b.  A  similar  papilla,  deprived  of  its  epithelium:  a,  basement-membrane  ;  6,  tabular 
(nerve)  fibre,  probably  forming  a  loop,  but  its  arch  not  clearly  seen  ;  e,  c,  elastic  fibrous  tissue  at  its 
base  and  in  its  interior.  (Magnified  320  diameters.)  c.  Nerves  of  a  compound  papilla  near  the  point 
of  the  tongue,  ia  which  their  loop-like  arrangement  is  distinctly  seen.    (Magnified  160  diameters.) 

Fig.  346. 


A  Fungiform  papilla,  showing  the  secondary  papill.-c  on  its  surface,  and  at  a,  its  epithelium  cover- 
ing them  over.  (Magnified  3.j  diameters.)  b.  The  capillary  loops  of  the  simple  papillse  of  a,  injected: 
<i,  artery  ;  v,  vein.  The  groove  around  the  base  of  some  of  the  fungiform  piipillse  is  here  represented, 
as  well  as  the  capillary  loops  (c,  c)  of  some  neighboring  simple  papilla;.     (JIagnifled  IS  diameters.) 

broad,  closely  surrounding  the  papilla,  especiall}''  at  its  base.    They 
are  arranged  so  as  to  correspond  to  the  letter  Y,  the  point  being 


518 


THE   TISSUES. 


constituted  by  the  foramen  ccecnm,  which  is  a  depression  containing 
fungiform  papillae.  The  papilla  itself  is,  in  structure,  to  be  regarded 
as  a  flattened  fungiform  papilla,  except  that  it  contains  no  elastic 
tissue;  and  the  wall  is  a  simple  elevation  of  the  mucous  membrane, 
with  a  smooth  epithelium,  under  which  its  upper  border  is  pro- 
duced into  many  rows  of  simple  conical  secondary  papillae.     (Fig. 

Fig.  347. 


Papilla  circamvallata  of  man,  in  section.    A.  Proper  papilla.    B.  Wall.    a.  Epithelium,    c.  Second- 
ary papilla;,    b,  h.  Nerves  of  tbe  papilla  and  of  the  wall. — Magnified  about  10  diameters.  {KUlliker.) 

347.)  Far  more  nerves  are  distributed  to  these  than  to  the  fungi- 
form papillae;  the  walls  also  being  abundantly  provided  with  them. 
Uses  of  the  Lingual  Papilla?. — The  filiform  papillas  are  neither  the 
seat  of  the  sense  of  taste,  nor  delicate  tactile  organs;  but  are  the 
analogues  of  the  lingual  spines  of  animals  {Todd  and  Bowman), 
and  hence  aid  in  mastication,  and  in  protecting  the  tongue.  The 
two  other  kinds  of  papillae  subserve  the  sense  of  taste,  and  are  also 
the  seat  of  touch,  temperature,  &c.  The  sense  of  touch  is  most 
acute  at  the  point  of  the  tongue  where  the  fungiform  papillas  are 
most  abundant;  the  sense  of  taste  at  the  root  of  the  tongue,  pro- 
bably because  the  circumvallate  papillas  possess  more  nerves  in  the 
same  space.  The  nerve-fibres  are  also  finer,  or  more  nearly  reduced 
to  isolated  axis-fibres. 

Certain  pathological  appearances  of  the  tongue  are  easily  under- 
stood from  the  data  just  afforded.  The  gastric  furred  tongue  is 
produced  principally  by  the  growth  of  the  epithelial  processes  of 
the  filiform  papillae,  which  i)rojecting  backwards  apparently  form 
a  peculiar  white  coating.  If  they  become  longer,  so  that  the  pa- 
pillae measure  \  to  \  of  an  inch,  the  appearance  called  the  villous 
tongue,  not  uncommon  in  various  disorders,  is  produced.  At  length, 
indeed,  the  tongue  may  seem  to  be  covered  with  hairs  4  to  6  lines 
long.  In  old  people,  the  tongue  may  present  no  papillas  at  all ; 
they  being  small  and  imbedded  in  the  epithelium.  Finally,  the 
mucediiKJUs  fungi  collecting  on  the  pajMlke  filiformes  may  produce 
a  thick  white  coat,  as  shown  by  Fig.  155. 


GLANDS  OF  THE  ORAL  CAVITY. 


519 


The  Glands  of  the  Oral  Cavity. 

The  sabinucous  areolar  tissue  of  the  mouth  presents  no  peculiari- 
ties, except  that  it  is  thin  and  yielding  on  the  fricna  of  the  lips, 
tongue,  and  epiglottis,  and  the  floor  of  the  mouth  ;  while  it  is  more 
solid  where  mucous  glands  occur ;  and  is  firmly  fixed  on  the  root 
of  the  tongue,  and  the  soft  palate,  where  there  are  also  large  masses 
of  fat  in  it.  The  glands  are  of  three  classes :  the  mucous,  the  fol- 
licular, and  the  salivary  glands. 

1.  The  mucous  glands  are  racemose,  yellowish,  or  whitish,  of  a 
rounded  form,  and  |  to  ^  of  an  inch  in  diameter.  (Fig.  348.)  Their 
terminal  vesicles,   or  cseca, 

precisely  resemble  a  simple  s-  <^48. 

sebaceous  gland.  They  ge- 
nerally lie  in  the  submu- 
cous areolar  tissue.  On  the 
lips  they  form  a  ring  about 
2^4  of  an  inch,  broad  round 
the  oval  aperture,  com- 
mencing \  of  an  inch  from 
the  red  edge  of  the  lips. 
They  are  very  numerous 
in  the  cheeks,  but  smaller. 
Those  of  the  hard  palate 
cover  only  its  anterior  half; 
while  those  of  the  soft  pa- 
late are  abundant,  but  di- 
minish towards  the  free 
edge  of  the  uvula.  Smaller 
glands  also  exist  on  its  pos- 
terior surface.  There  are 
no  glands  upon  the  gums. 
The  mucous  glands  of  the 

root  of  the  tongue  are  -^^  to  ^  of  an  inch  in  diameter.  They  form 
a  stratum  in  some  parts  very  thick,  extending  almost  from  one 
tonsil  to  the  other.  They,  however,  never  extend  forwards  beyond 
the  middle  of  the  tongue.  The  ducts  of  some  of  these  glands  which 
lie  in  the  extremity  of  the  genio-glossus  muscle,  are  even  half  an 
inch  long.  Other  small  glands  lie  on  the  margin  of  the  root  of  the 
tongue;  and  two  elongated  glandular  masses  -^-  to  §  of  an  inch  long, 
1  to  ^  of  an  inch  thick,  and  \  to  4  of  an  inch  broad,  lie  under  the 


■■6j 


Human  racemose  mucous  glauil  liom  the  ll'.iv)i-  of  the 
oral  cavity,  a.  Investment  of  areolar  tissue,  h.  Ex- 
cretory duct.  c.  Glandular  vesicles  (citca).  d.  Ducts  of 
tlie  lobes. — Magnified  50  diameters.    (Kijlliker.) 


520  THE    TISSUES. 

point  of  the  tongue  each  side  of  the  frteuum,  where  five  or  six  ex- 
cretory ducts  open  close  to  the  latter. 

All  these  glands  are  abundantly  supplied  with  bloodvessels,  each 
of  the  C£eca  and  vesicles  being  usually  in  contact  with  three  or  four 
capillaries.  Nerves  also  exist  abundantly  upon  the  excretory 
ducts,  and  occasionally  fine  fibres  are  found  in  the  glands  them- 
selves. 

The  mucus,  secreted  by  these  glands,  has  already  been  described 
(p.  198). 

2.  The  simple  follicular  glands  are,  when  dissected  out,  0*4  to  \  of 
an  inch  in  diameter,  and  are  found  at  the  root  of  the  tongue  lying 
under  the  mucous  membrane,  but  above  the  mucous  glands;  and 
so  superficially  that  their  position  is  seen  externally.  Indeed,  the 
excretory  ducts  of  the  mucous  glands,  before  described,  open  into 
the  bottom  of  these  follicles  or  sacs.  Each  of  these  is  a  cavity 
lined  by  the  mucous  membrane  of  the  tongue,  with  its  papillae  and 
epithelium;  with  a  number  of  large  completely  closed  capsules  j\-^ 
to  4'g  of  an  inch  in  diameter,  and  with  walls  goVo-  to  4o'oo  of  an 
inch  thick,  lying  immediately  under  the  membrane  in  a  delicate 
fibrous  and  vascular  matrix.  (Fig.  349.)  Their  contents  are  gray- 
ish-white, consisting  of  a  clear  fluid,  cells  4 oVd  to  sioir  of  an  inch 
in  diameter,  and  free  nuclei,  enou  to  guVo  of  an  inch  in  diameter. 

Fig.  349. 


Iluinau  follicular  gland  from  the  root  of  thn  toiigiio.  a.  Epithelium  liuing  it.  b.  Papilla,  c. 
External  surface  of  the  follicular  gland  with  the  coat  of  connective  tissue,  e.  Cavity  of  the  gland. 
/.  Epithelium,     g.  Follicle  in  the  thick  wall  of  the  gland. — Magnified  30  diameters.    (Kijlliker.) 

These  glands  are  abundantly  supplied  with  vessels,  forming 'close 
networks  upon  the  membrane  of  the  capsules  (Fig.  350),  and  then 
proceeding  to  supply  the  papillae.  Lymphatic  vessels  also  proceed 
from  them  {E.  II.  Weher),  and  nerves  exist  upon  them. 

Of  the  compound  follicular  glands  the  tonsils  are  an  example, 


GLANDS   OF   THE   ORAL   CAVITY. 


521 


Each  of  these  orecans  is  an  a^^f^re- 


Fig.  350. 


though  found  in  the  pharynx, 
gation  of  10  to  20  compound 
follicular  glands,  held  together 
by  a  common  investment,  and 
forming  a  hemispherical  mass. 
The  apertures  of  the  follicles 
frequently  unite  so  as  ulti- 
mately to  form  only  a  small 
number  on  the  surface.  The 
structure  of  the  tonsil  is,  there- 
fore, understood  from  the  pre- 
vious description  of  the  sim- 
ple follicular  glands.  It  should 
also  be  added,  that  the  tonsils 
receive  the  ducts  of  mucous      ^'^^^  °!''^'^  ^'f''"'  ^'Z  '^  ^TT"  !°°'"' 

seen  from  the  canty  of  a  sac. — Magnified  60  diame- 

glands.      The   vessels    distri-    ters.   (Kimker.) 

buted  to  the  closed  capsules 

are  more  numerous  than  those  of  the  lingual  follicles.     (Fig.  350.) 

Nerves  exist  on  the  surface  of  the  tonsil  and  in  the  papillae;  but 

have  not  been  found  in  the  membrane  of  the  closed  capsules. 

What  the  precise  function  of  the  closed  capsules  is,  is  not  deter- 
mined. But  at  least  their  contents  are  very  similar  to  those  in  the 
follicular  cavity  around  which  they  lie,  though  no  capsules  are 
found  burst. 

3.  The  salivary  glands  (parotid,  submaxillary  and  sublingual), 
may  be  regarded  as  compound  racemose  mucous  glands,  so  far  as 
their  structure  is  concerned;  their  primary  lobules  corresponding 
to  those  of  a  mucous  gland,  and  their  secondary  to  the  entire  mu- 
cous gland.  (Fig.  348).  These  last  are  united  into  larger  lobes,  and 
thus  the  whole  salivary  gland  is  made  up.     (Fig.  316,  c.) 

The  excretory  ducts  of  the  salivary  glands  have  a  conoidal  epi- 
thelium consisting  of  a  single  layer  of  cells  ^^-^  of  an  inch  long. 
The  remainder  of  their  wall  (very  thick  in  Stenon's  duct),  is  a  firm 
and  condensed  layer  of  areolar  tissue.  In  Wharton's  duct,  there  is 
a  thin  layer  of  smooth  muscular  fibres  within  the  areolar  tissue; 
while  there  is  also  a  double  elastic  \ajeT  between  this  muscular 
layer  and  the  epithelium.  The  vessels  are  abundantly  distributed 
to  the  primary  lobules,  as  to  those  of  the  mucous  glands;  the  capil- 
laries being  ^^Vu  to  -g  i)V(y  of  an  inch  in  diameter.  Lymphatics  are 
also  found  in  the  salivary  glands.     Nerves  proceed  into  them  also, 


522  THE   TISSUES. 

with  the  vessels,  from  the  external  carotid  plexus;  besides  which, 
the  ganglion  linguale  supplies  the  two  smaller  pairs  of  glands,  and 
the  facial  nerve,  probably  with  the  anterior  auricular,  the  parotid. 

The  composition  and  uses  of  the  saliva  have  already  »been  speci- 
fied (pp.  209-10). 

2.  Mucous  Membrane  of  the  Pharynx. 

Only  the  lower  half  of  the  pharynx  will  be  noticed  here;  the 
upper  half  belonging  to  the  respiratory  passages.  In  that  part  of 
it  through  which  the  food  passes,  the  epithelium  is  of  the  com- 
pound scaly  variety,  like  that  of  the  oral  cavity.  The  corium  of 
the  mucous  membrane  contains  much  more  elastic  tissue  than  that 
of  the  mouth,  is  paler,  and  presents  none  but  rudimentary  papillae. 

The  glands  in  the  lower  half  of  the  pharynx  are,  1,  racemose 
mucous  glands,  already  described  (p.  519),  in  small  numbers;  2, 
follicular  glands — especially  on  the  posterior  and  lateral  walls  of 
the  pharynx,  as  far  as  to  the  level  of  the  epiglottis;  3,  the  tonsils 
already  described  (p.  521).  The  first  two  kinds  of  glands  are,  how- 
ever, far  more  abundant  on  the  upper  half  of  the  pharynx,  as  will 
be  shown  further  on  (Chap.  XVI.). 

Bloodvessels,  lymphatics,  and  nerves,  abound  in  the  mucous 
membrane  of  the  pharynx.  The  muscles  of  the  pharynx  are  the 
three  constrictors,  the  stylo-pharyngeus,  and  the  palato-pharyngeus. 

3.  Structure  of  the  CEsophagus. 

While  the  muscular  coat  of  the  pharynx  is  formed  of  striated 
muscular  fibres  alone  (the  constrictores  pharyngis,  &c.),  that  of  the 
oesojihagus  contains  both  kinds  of  fibres.  In  its  upper  third,  as 
far  as  its  entrance  into  the  thorax,  only  the  striated  muscular  fibres 
are  found,  arranged  in  fasciculi  ^^^  to  ^V  of  an  inch  in  diameter, 
and  which  sometimes  distinctly  anastomose.  Lower  down,  the 
smooth  muscular  fibres  appear,  first  in  the  circular  (internal)  layer; 
and  then  increase  while  the  striated  fibres  diminish — though  the 
latter  are  found  isolated,  and  extending  even  to  the  cardia.  {Fi- 
ciims.) 

The  mucous  membrane  is  paler  than  that  of  the  pharynx,  and 
assumes  a  whitish  tint  below.  It  is  -3^3  to  ^'g  of  an  inch  thick;  its 
compound  scaly  epithelium  being  y^,j  to  ^}iX)  of  an  inch  thick;  and 
whose  epithelial  plates,  constituting  one-half  its  thickness,  may  be 
readily  stripped  off  in  large  white  sheets,  after  a  short  maceration. 


ALIMENTARY   CANAL  — STOMACH.  523 

The  corium,  averaging  ^\  of  an  inch  thick,  presents  numerous 
conical  papilhu,  and  consists,  besides  areolar  tissue,  of  very  many 
longitudinal  bundles  of  smooth  muscular  fibres.  It  also  contains 
fat  cells  and  small  racemose  mucous  glands.  (Fig.  348.) 

The  mucous  membrane  of  the  oesophagus  is  moderately  sup- 
plied with  bloodvessels,  lymphatics,  and  nerves.  The  last  have  not 
yet  been  traced  into  the  papilla. 

The  Infra-diaphragmatic  Portions  of  the  Alimentary 
^  Canal. 

All  the  infra-diaphragmatic  portions  of  the  alimentary  canal 
(except  a  small  part  of  the  rectum)  have  still  another  layer  ex- 
ternal to  the  muscular  coat,  viz.,  the  periloneum.  This  serous  mem- 
brane forms  a  closed  cavity;  its  epithelium  being  of  the  simple 
scaly  variety.  Its  corium  is  much  thicker  in  the  external  or  parie- 
tal layer,  than  in  the  internal  or  visceral;  though  having  in  both 
the  same  structure — like  that  of  the  corium  of  the  skin.  The 
whole  thickness  of  the  membrane  is  g^^  to  o^o  of  an  inch  in  the 
latter  case,  and  ^^^  in  the  former.  A  loose  sub  serous  layer  of 
areolar  tissue  containing  fat-cells  exists  in  most  parts;  not,  however, 
in  the  folds  of  the  peritoneum.  But'few  vessels  or  nerves  are  dis- 
tributed to  this  membrane;  and  lymphatics  have  been  found  only 
in  the  sub-serous  layer. 

Any  peculiarity  in  the  muscular  coat  will  be  specified  in  connec- 
tion with  the  part  in  which  it  occurs.  In  general,  it  consists  of  an 
incomplete  layer  of  longitudinally  arranged  fasciculi  of  smooth 
muscular  fibres  externally,  and  another  of  circular  fibres  internally. 
The  stomach  has  also  a  third  layer  of  oblique  fibres  inside  of  the 
circular  layer. 

1.   The  Structure  of  the  Stomach. 

The  m.ucous  membrane  of  the  stomach  is  reddish-gray,  or  bright 
red  during  digestion,  but  at  other  times  grayish.  It  is  thinnest 
{li  ^o  7a  of  an  inch)  at  the  cardia;  and  thickest  in  the  pjdoric 
region  (x^g  to  ■/.>-  of  an  inch).  Little  polygonal  areas,  ^^  to  \  of  an 
inch  across,  bounded  by  very  slight  depressions,  are  not  uufre- 
queutly  found  on  the  pyloric  portion  of  the  membrane.  Dr.  Neil 
has  shown  tliat  conical  papill;e  exist  around  the  pjdorus,  similar  to 
the  villi  of  the  small  intestine,  but  smaller. 

The  corium  of  the  mucous  membrane  contains  a  layer  of  smooth 


524 


THE   TISSUES. 


Fig.  351 

pfiififiiliiliilfjl 


r 


muscular  fibres  in  its  lowest  portion,  above  which  all  is  areolar  tis- 
sue. The  muscular  layer  and  the  simple  conoidal  epithelium  are 
everywhere  of  the  same  thickness,  while  the  intermediate  portion — 
the  glandular  layer — varies. 

The  most  important  element  of  the  gastric  mucous  membrane — 
the  gastric  glands — are  straight  tubes  passing  through  the  membrane 

down  to  its  muscular  layer,  and  there- 
fore varying  in  different  parts  from  ^-Q  to 
j'g  of  an  inch  in  length.  They  are  so 
crowded  together  that  very  little  tissue 
intervenes  between  them.  (Fig-  351.) 
They  commence  on  the  surface  as  cylin- 
drical tubes  4  0^0  0  to  3  oVo  of  ^^  vaoh  in 
diameter,  diminish  below  to  g^Viy  of  an 
inch,  or  less ;  and  the  most  common  form 
terminates  in  a  flask-shaped  enlargement 
of  4gTT  to  T^a  of  an  inch.  Each  tube  is 
lined  through  its  upper  third  by  a  simple 
conoidal  epithelium ;  but  in  the  rest  of 
its  extent  the  tube  is  entirely  filled  with 
pale,  finely  granular,  nucleated  cells, 
soVtt  to  isVo  of  an  inch  in  diameter, 
which  do  not  seem  to  constitute  a  dis- 
tinct epithelium.  They  are  termed  the 
peptic  cells ;  and  these  are  the  simple  j^ep- 
tic  glands  occurring  in  the  middle  zone 
of  the  stomach.  The  compound  p)eptic 
glands  (Fig.  352,  c)  occur  in  the  narrow 
cardiac  zone  of  the  stomach.  They  resemble  the  preceding,  except 
that  they  divide  into  two  or  three,  and  then  into  four  to  seven 
equally  long  cylindrical  tubules,  also  lined  by  the  peptic  cells;  in 
which  oil-globules  are  frequently  observed.  The  terminal  lobules 
have  a  twisted  appearance  dependent  on  numerous  lateral  dilata- 
tions. Smooth  muscular  fibres  are  also  found  between  these  glands. 
Still,  other  compound  tubular  glands  also  exist  in  the  pyloric  zone, 
resembling  the  last,  except  that  they  are  larger  and  lined  throughout 
by  a  conoidal  epithelium,  and  therefore  contain  no  peptic  cells. 
(Fig.  852,  B.) 

It  is  pretty  certain  that  the  true  gastric  juice  is  afforded  only  by 
the  two  forms  of  peptic  glands  just  described;  while  the  last  men- 


Perpcndicular  section  through  the 
tunics  of  tlie  pig's  stomach,  from  the 
X)ylorus.  a.  Glands.  6.  Muscular 
layer  of  mucous  membrane,  c.  Sub- 
mucous tissue  {tunica  nervea)  with 
divided  vessels,  d.  Transverse  mus- 
cular layer,  e.  Longitudinal  mus- 
cular layer.  /.  Serous  membrane. — 
llagnificd  30  diameters.     {Kolliker.) 


STRUCTURE   OF   THE   STOMACH. 


525 


tioned  secrete  mucus  alone.  The  pepsin  is,  therefore,  afforded  only 
by  the  cardiac  and  middle  zone  of  the  stomach,  and  not  by  the 
pyloric. 

Fig.  352. 


A  and  c.  Peptic  gastric  glands,  from  the  middle  of  the  stomach,  b.  Mucous  gland  from  pyloric 
region,  a,  trunk  of  the  glands  ;  6,  branches  ;  c,  terminal  caeca  ;  d,  termination  of  mucous  gland,  b, 
lined  with  conoidal  epithelium,  d.  Portion  of  cieca  of  c,  magnified  3.50  diameters,  e.  The  same, 
transverse  section,  a,  basement  membrane  ;  6,  large  cells  ;  c,  small  epithelial  cells,  a  and  b,  from 
the  dog — 200  diameters  ;  c,  60  diameters.    (Ki'lliker.) 

The  bloodvessels  of  the  gastric  mucous  membrane  are  very 
numerous,  and  their  distribution  quite  characteristic.  Fig.  853 
represents  those  of  the  large  intestine,  which  are  very  similar. 
The  arteries,  beginning  to  divide  in  the  submucous  areolar  tissue, 
break  up  into  capillaries  of  g^Vo  to  4X)'o7  of  an  inch,  which  ascend 
between,  and  form  a  network  around  the  tubular  glands,  extending 
as  far  as  their  apertures,  and  forming  pol3^gonal  meshes  around  the 
latter  gJ-y-  to  gj-^  of  an  inch  in  diameter.  From  this  network  the 
veins  rise  by  many  radicles,  and  penetrating  the  glandular  la3'-er 
further  apart  than  the  arteries,  enter  a  venous  network  with  partly 
horizontal  vessels,  in  the  submucous  tissue. 


526 


THE   TISSUES. 


Fig.  353. 


Vessels  of  the  large  intestine 
of  a  dog,  the  mucous  membrane 
being  cut  through  perpendicu- 
larly, a.  Artery,  h.  Capillary 
network  of  the  surface  with 
glandular  apertures,  c.  Vein. 
d.  Capillary  networlc  round  the 
glandular  tubules  in  the  thick- 
ness of  the  mucous  membrane. — 
(KlUtker.) 


354, 


Sectiiin  ul'  iliu  imicuus  iiiuinbrano  of  the  small 
intestine  of  the  dog,  showing  Lieberkiihn's  folli- 
cles and  the  villi,  a.  Villi.  6.  LioborkOhn's  folli- 
cles,   c.  Other  coats  of  the  intestine. 


The  lymphatic  vessels  of  the  gastric  mu- 
cous membrane  form  two  networks;  a  fine, 
superficial,  and  a  deep,  coarse  one.  The 
nerves,  derived  from  the  pneumogastric  and 
the  sympathetic,  have  been  seen  to  enter 
the  muscular  layer  of  the  mucous  mem- 
brane, but  have  not  been  traced  further. 

2.  Structure  of  the  Small  Intestine. 

The  small  intestine  is  divided  into  the 
duodenum.,  the  jejunum,  and  the  ileum. — 
Throughout,  the  mucous  membrane  has  a 
simple  conoidal  epithelium  ;  and  its  corium 
has  a  layer  of  smooth  muscular  fibres  both 
longitudinal  and  transverse  (described  by 
Briicke),  like  that  of  the  gastric  mucous 
membrane;  and,  at  most,  ^^^  of  an  inch 
thick.  Where  certain  glands  exist,  there  is 
but  little  submucous  tissue,  the  corium  be- 
ing closely  connected  with  the  muscular 
tunic  of  the  intestine.  It  is  more  compli- 
cated in  structure,  though  thinner  than  the 
membrane  of  the  stomach;  pre- 
senting, as  it  does,  the  villi  and 
several  varieties  of  glands. 

I.  The  villi  (Fig.  354)  ex- 
tend throughout  the  small  intes- 
tine from  the  pylorus  to  the 
sharp  edge  of  the  ileo-c^cal 
valve,  being  most  numerous 
(50  to  90  upon  a  square  line)  in 
the  duodenum  and  jejunum ; 
wliile  there  are  but  40  to  70  on 
the  same  surface  in  the  ileum. 
They  are  whitish  elevations  of 
the  corium  of  the  mucous  mem- 
brane, easily  seen  by  the  unaid- 
ed eye,  and  arc  set  so  close  to- 
gether upon    and   between  the 


STRUCTURE    OF   THE   SMALL    INTESTINE. 


527 


valvulce  conniventes  as  to  give  to  the  membrane  its  velvety  appear- 
ance. In  the  duodenum  they  are  broader  and  less  elevated,  resem- 
bling folds  and  laminae  y^^  to  -^^  of  an  inch  high,  and  ^y'^  to  even 
jg  of  an  inch  broad.  In  the  jejv.mim  they  are  mostly  conical  and 
flattened,  and  often  cylindrical,  clavate,  or  filiform  ;  being  g'^  ^^  ^-^ 
of  an  inch  long,  r^'^  ^o  to(J  of  an  inch,  or  less,  in  breadth,  and  ^^g 
of  an  inch  (in  the  flattened  forms)  thick.  The  epithelium  of  the 
villi  is  the  simple  conoidal  variety.  The  proper  villus  itself  is  sim- 
ply a  solid  process  of  the  corium  whose  matrix  is  undeveloped  col- 
lagenous tissue,  in  which  a  variable  number  of  roundish  free  nuclei 
are  scattered;  containing  bloodvessels,  lymphatics,  and  smooth 
muscular  fibres.  The  bloodvessels  are  very  numerous.  Two  or 
three  small  arteries  (xoVy  to  ;y^^  of  an  inch)  give  off  a  close  net- 
work of  capillaries,  4uV(j  to  s^Vir  of  an  inch  in  diameter,  which 
lies  immediately  beneath  the  basement  membrane  on  the  outer 
surface  of  the  proper  villus  itself.  From  the  gradual  confluence 
of  these  capillaries  a  vein  arises  which  carries  the  blood  into  the 
larger  trunks  of  the  submucous  tissue.     (Fig.  355.)     The  lym-pha- 


Fig.  355. 


Fig.  356. 


Fig.  355.  Vertical  section  of  tlie  coats  of  the  small  in- 
testine of  a  dog,  showing  only  the  commencing  por- 
tions of  the  portal  veins,  and  the  capillaries.  The 
injection  has  been  thrown  into  the  portal  vein,  but 
has  not  penetrated  to  the  arteries,  a.  Vessels  of  the 
villi.  6.  Of  Lieberkiihn's  tubes,  c.  Of  the  muscular 
coat. 

Fig.  356.  Two  villi  without  epithelium,  and  with  the 
lacteals  in  their  interior  (from  the  calf)  ;  treated  with 
a  dilute  sohition  of  caustic  soda. — {Ki'lliker.) 


528  THE   TISSUES. 

tics  of  the  villi  are  usually  called  lacteals.  These  traverse  tlie  axis 
of  the  villus,  commencing  in  a  csecal  and  frequently  enlarged  end. 
(Fig.  356.)  They  have  a  much  greater  diameter  than  the  capilla- 
ries, and,  according  to  Professor  Briicke,  are  mere  excavations  in 
the  villi  without  walls,  while  the  true  chyliferous  vessels  commence 
in  the  deeper  parts  of  the  membrane.  In  some  broad  villi,  two 
lacteal  cavities,  a  long  and  a  short,  appear. 

The  smooth  muscular  fibres  of  the  villi  are  arranged  longitudinally, 
forming  a  thin  layer,  not  always  distinct  in  man,  placed  centrally 
around  the  lacteals.  They  produce  contractions,  and  thus  influence 
the  propulsion  of  the  chyle  and  the  venous  blood  in  the  villi. — 
Nothing  is  known  of  any  nerves  in  them. 

Function  of  the  Villi. — The  villi  are  the  principal  agents  of  ab- 
sorption of  the  nutritive  elements  resulting  from  the  digestion  of 
the  food.  But  Briicke  shows  that  absorption  also  occurs  on  the 
surfaces  between  them,  and  particularly  from  between  the  glands 
of  Lieberkiihn.  It  is  generally  asserted  that  the  lacteals  alone 
absorb  fat,  while  the  minute  bloodvessels  absorb  the  other  elements. 
Briich,  however,  found  that  the  bloodvessels  absorb  fat  as  well  as 
the  lacteals;  the  former  sometimes  being  half  filled  with  fat,  instead 
of  blood  alone.  Both  these  observers  also  show  that  the  epithelium 
of  the  villi  is  not  cast  ofi'  during  normal  digestion,  as  stated  by  Mr. 
Goodsir.  Briicke  asserts  that  the  epithelial  cells  are  mere  tubes, 
closed  externally  by  a  layer  of  mucilaginous  substance  easily  per- 
meable by  fluids,  and  that  the  fat  therefore  finds  an  easy  admission 
into  them,  and  to  the  surface  and  into  the  substance  of  the  proper 
villus  itself,  in  the  form  of  oil-drops.  This  observation  needs  con- 
firmation. 

In  cholera,  the  epithelium  of  the  villi,  and  sometimes  of  the 
whole  intestine,  is  thrown  off. 

II.  The  fjlands  of  the  small  intestine  are  of  two  kinds,  the  tubular 
and  the  racemose.  Certain  closed  follicles  are,  however,  also  to  be 
descriVjed  in  this  connection. 

1.  The  tubular,  or  Lieberklihn's,  glands  arc  distributed  over  the 
whole  small  intestine,  as  straight,  narrow  caeca  (B'ig.  357),  extending 
completely  through  the  mucous  membrane,  and  occupying  almost 
all  the  space  left  between  the  villi;  and,  in  a  vertical  section  (Fig. 
359  and  362),  resembling  palisades.  They  are,  however,  not  found 
over  the  centre  of  the  closed  follicles,  as  will  be  seen.  Their  length 
equals  the  thickness  of  the  mucous  membrane  (^^^  to  g'j  of  an  inch); 


STRUCTURE   OF  THE   SMALL   INTESTINE. 


529 


their  breadth  is  ^^g  to  ^  Jg  of  an  inch;  and  their  aperture  is  g^^  to  -^^xi 
of  an  inch.    They  contain  a  simple  conoidal  epithelium,  whose  cells 


¥is.  357. 


Fig.  358. 


B  r_ 


Fig.  3.>7.  A.  Transverse  section  of  Lioberkfihn's  tubes  or  follicles,  shoiring  the  basement-mem- 
brane and  the  sub-conoidal  epithelium  of  their  walls,  with  the  areolar  tissue  connecting  the  tubes  : 
a,  basement-membrane  and  epithelium  constituting  the  wall  of  the  tube  ;  b,  cavity  or  lumen  of  the 
tube.  (Magnified  200  diameters.)  b.  A  single  Lieberkiihn"s  tube,  highly  magnified;  an  accidental 
section  in  the  oblique  direction  displays  very  distinctly  the  form  and  mode  of  packing  of  the  epithe- 
lial cells,  the  cavity  of  the  tube,  and  the  mosaic  pavement  of  its  exterior:  a,  basement-membrane  ; 
c,  internal  surface  of  the  wall  of  the  tube.    (Magnified  200  diameters.) 

Fig.  358.   Distribution  of  capillaries  around  follicles  of  mucous  membrane. 

during  digestion  never  contain  fat,  like  those  of  the  villi;  the  lumen 
of  the  tube  being  filled  by  a  clear  fluid  secretion — the  intestinal 
fluid — already  described  on  page  201.  The  vessels  of  these  glands 
follow  the  type  of  those  of  the  stomach.    (Figs.  358,  355,  and  353.) 

2.  The  racemose  glands — Brunner's  glands — most  abundant  in 
the  duodenum,  resemble  those  of  the  oral  cavity  and  the  salivary 
glands,  in  structure,  and  their  vessels  have  the  same  arrangement 
as  those  of  the  latter.  (Fig.  348.)  Thus  the  vessels  whence  the 
secretion  of  these  and  the  preceding  glands  is  obtained  are  next  to 
the  arteries,  while  those  concerned  in  absorption  (those  of  the  villi) 
are  further  from  them,  and  nearer  to  the  veins.  (Fig.  355.) 

3.  The  closed  follicles  are  found  scattered  simply  or  in  groups  over 
the  walls  of  the  small  intestine.  In  groups,  they  constitute  the 
Peyer's  patches,  or  glandulce  agminaice.  Each  closed  follicle  is  ^^.r 
to  5^4  or  even  j'g  of  an  inch  in  diameter,  rounded  or  conical  towards 
the  intestinal  cavity,  and  lying  partly  in  the  corium  of  the  mucous 
membrane,  and  partly  under  it;  extending  from  a  point  g-^^j  to  ^^^ 
of  an  inch  beneath  its  surface  to  the  muscular  tunic,  which  is  here 
more  closely  united  with  the  corium.  (Fig.  359.)  On  the  surface 
of  the  mucous  membrane  are  roundish  depressions,  -g'g  to  j'^  of  an 
inch  apart,  corresponding  to  the  separate  follicles,  and  presenting 

34 


530 


THE   TISSUES. 
Fig.  359. 


Fig.  3G0. 


Vertical  section  tlirough  a  patcli  of  Peyer's  glands  in  the  dog.  a.  Villi,  b.  Olands  of  Lieberkuhn, 
with  the  apices  of  Peyer's  glands,  c.  Submucous  tissue,  with  the  glands  of  Peyer  imbedded  in  it. 
d.  Muscular  and  peritoneal  coats,  e.  Apex  of  one  of  Peyer's  glands  projecting  among  the  tubes  of 
Lieberkuhn.  s.  Its  contents.  The  glands  are  seen  laid  open  by  the  section.  (Magnified  about  20 
diameters.) 

no  villi.  When,  however,  the  follicles  are  isolated  (gland ulse  soli- 
tarise),  they  usually  present  a  convex  surface,  and  support  villi. 
(Fig.  360.)  Each  follicle  has  a  completely  closed,  thick,  and  strong 
coat  of  indistinctly  iibrillated  collagenous  tis- 
sue, with  interposed  nuclei;  within  which  are 
the  soft  grayish  contents,  consisting  of  a  little 
fluid,  and  innumerable  nuclei  and  round  cells, 

so'ou  ^^  tsVtj  ^^  ^^  ^^^^  ^^  diameter.  Very 
fine  bloodvessels  ramify,  like  those  of  the  closed 
follicles  of  the  tonsils,  on  the  exterior  of  these 
follicles  (Fig.  350),  and  penetrate  to  their  inte- 
rior. {Frei  and  Ernst'.)  Lymi^hatics  also  form 
networks  around  them;  but  do  not  enter  them, 
as  Briicke  asserted.  [KolliJcer.) 

The  patches  of  Peyer  are  from  20  to  30  in 
number,  when  confined,  as  usual,  to  the  ileum  and  lower  part  of  the 
jejunum;  from  50  to  60  when  extending  nearly  to,  or  even  into,  the 
duodenum.  They  are  rounded  or  elliptical  in  form,  always  situated 
on  the  portion  of  intestine  opposite  the  mesentery,  and  are  \  of  an 
inch  to  even  1  inch  long,  and  \  to  even  f  of  an  inch  broad.  They 
are  mere  aggregations  of  the  closed  follicles  just  described,  each 


.\  sdiitarv  ^liiiid  from  the 
small  intestine  of  the  liu- 
man  subject.  —  Magnified. 
(After  Boehm.) 


MUCOUS   MEMBRANE   OF  THE   LARGE   INTESTINE. 


531 


follicle  being  surrounded  by  the  apertures  of  Lieberkiihn's  glands, 
6  to  10  in  number,  as  shown 
by  Fig.  361. 

We  have  as  yet  no  certain 
knowledge  of  the  functions  of 
the  closed  follicles  of  the  small 
intestine.  They  become  ulcer- 
ated in  typhoid  fever,  and  arc 
subject  to  various  other  patho- 
logical conditions. 


3.  Mucous  Memlrane  of  the 
Large  Intestine. 

This  agrees  mainly  in  struc- 
ture with  the  mucous  mem- 
brane of  the  small  intestine. 
Its  peculiarities,  therefore,  will 
alone  be  specified.    It  presents 

no  villi,  but,  aside  from  occasional  wart-like  elevations,  it  is  level 
and  smooth.  The  muscular  layer  is  difficult  to  detect,  except  in  the 
mucous  membrane  of  the  rectum. 

The  glands  of  the  large  intestine  are:  1.  Lieberkiihn's  glands, 
precisely  resembling  those  of  the  small  intestine,  except  that  they 
are  longer  and  broader,  to  cor- 


Portion  of  one  of  the  patches  of  Payer's  glands, 
from  the  end  of  the  ilium  ;  moderately  magnified. 
The  villi  and  Lieberkiihn's  glands  are  also  displayed. 


respond  with  the  greater  thick- 
ness of  the  membrane  {-^^  to 
^\  of  an  inch,  by  yi^  to  o-i^). 
They  are  distributed  over  the 
whole  surface  from  the  ileo- 
cgecal  valve  to  the  anus.  2. 
The  solitary  closed  follicles  are 
very  frequent  in  the  colon  and 
rectum,  and  usually  more  abun- 
dant in  the  latter  than  in  the 
small  intestine.  They  are  larg- 
er than  in  the  latter  locality 
(y'g  to  even  \  of  an  inch  in  dia- 
meter), and  upon  each  of  the 
little  prominences  to  which  the 
follicles   give   rise   there   is  a 


362. 


^f^^P^w 


Solitary  follicle  from  the  colon  of  a  child,  n. 
Lieberkiihn's  glands,  h.  Muscular  layer  of  the  mu- 
cous membrane,  e.  Submucous  tissue,  d.  Trans- 
verse muscular  fibres,  fi.  Serous  membrane.  /.De- 
pression of  mucous  membrane  above  the  follicles 
(?.— Jlagnifled  45  diameters.  (KiiUiker.) 


532 


THE   TISSUES. 


small,  pit-like,  elongated  or  rounded  aperture,  j^g  to  y^^  of  an.  inch 
in  diameter,  in  the  mucous  membrane.  (Fig.  362.)  The  function 
of  these  closed  follicles  is  also  unknown. 

The  bloodvessels  of  the  preceding  glands  have  the  same  rela- 
tions as  in  the  small  intestine.  (Fig.  353.)  Nothing  is  known  of 
either  the  lymphatics  or  the  nerves  of  the  mucous  membrane  of 
the  large  intestine. 


The  Appendages  to  the  Alimentary  Canal. 
1.  The  Liver. 

Referring  to  the  works  on  descriptive  anatomy  for  all  other  par- 
ticulars in  regard  to  the  liver,  such  only  will  be  specified  here  as 
are  necessary  to  give  an  idea  of  its  minute  structure. 

The  vena  portee,  the  hepatic  artery,  and  the  hepatic  duct  enter 
the  transverse  fissure  of  the  liver,  and,  subdividing,  at  last  termi- 
nate— the  first  two  in  a  capillary  plexus  from  which  the  hepatic 
vein  commences,  and  the  last  in  immediate  contact  with  the  plexus. 
In  the  pig,  and  some  other  animals,  the  minute  structures  just  men- 
tioned are  so  inclosed  as  to  constitute  distinct  lobules,  and  it  is  the 
lobules  in  this  animal  which  Kiernan  first  accurately  described 
and  figured.  In  man,  however,  nothing  of  the  kind  occurs,  as 
E.  H.  Weber  first  demonstrated ;  the  various  structural  elements 
being  intimately  connected  throughout  the  whole  organ.    Still,  the 

distribution   of  the   capillaries 


Fig.  363. 


Horizontal  section  of  throe  siiporflcial  lobules  of 
the  liver,  Hhowing  the  two  principal  HyKtoms  of 
bloodvossels.  1,  1,  Interlobular  veins  proceeding 
from  the  hepatic  veinH.  2,  2.  Interlobular  ([lortal- 
hepatic)  plexus,  formed  by  branches  of  the  portal 
vein.  (Pig.) 


and  ducts  is  such  as  to  give 
rise  to  little  islets  in  the  liver, 
somewhat  analogous  to  the  lo- 
bules above  mentioned,  ^i'hese 
are  masses  of  the  hepatic  sub- 
stance, 5'g  to  t'j  of  an  inch  in 
diameter,  containing  some  of  the 
minutest  branches  of  the  vena 
port£e  and  the  hepatic  artery  ex- 
ternally, and  giving  ofi"  in  their 
centre  a  small  twig  of  the  hepa- 
tic vein.  Between  these  vessels 
the  portal  hepatic  plexus  of  ca- 
pillaries is  found.  (Fig.  368.) 
Tlie  hepatic  ducts  arise  in  the 
meshes  between  the  vessels  of 


APPENDAGES  TO  THE  ALIMENTARY  CANAL. 


533 


the  plexus,  and  accompany  the  finest  ramifications  of  the  portal 
vein,  so  that  the  bile  flows  in  a  direction  opposite  to  that  of  the 
blood.  Finally,  the  spaces  in  the  islets  left  between  the  elements 
just  described  are  occupied  by  the  so-called  hepatic  cells.  Thus,  in 
general,  is  an  islet  in  the  human  liver  composed ;  the  capillary 
plexus,  however,  being  common  to  all  the  contiguous  islets,  and 
continuous  between  them.  The  capsule  of  Glisson,  composed  of 
areolar  tissue,  invests  the  vena  portas,  hepatic  artery,  and  hepatic 
duct,  as  far  as  to  the  branches  going  to  the  islets ;  but  it  extends 
between,  and  isolates  the  latter  into  distinct  lobules,  only  in  the 
pig,  so  far  as  has  yet  been  ascertained. 

The  passages  in  the  liver  containing  Glisson's  capsule  with  the 
vessels  just  mentioned,  are  called  t\iQ  portal  canals.    (Fig.  36-i.) 


Fi2.  364. 


Fig.  365. 


Fig.  364.  A  transverse  section  of  a  small  portal  canal  and  its  vessels ;  after  Kiernan.  4.  Portal 
vein.  9.  Interlobular  branches.  5.  Branches  of  the  vein,  also  giving  off  interlobular  branches 
(vaginal  branches,  Kiernan.)  7.  Hepatic  duct.  6.  Hepatic  artery.  2.  Hepatic  vein.  The  lobules 
are  seen  in  outline. 

Fig.  36.3.  Hepatic  cells  of  man.  «.  Xormal  colls,  h.  With  pigment,  c.  With  fat  — Magnified  40O 
diameters.  {Killikf.r.) 

More  particularly,  the  hepatic  cells  (Fig.  365)  are  described  by 
Kcilliker  as  averaging  ygVcr  to  xAtr  of  ^^  moh  in  diameter,  the  ex- 
tremes beino;  ^,-^1^-^  and  ^\-r,  of  an  inch.    Their  membrane  is  smooth 


75  0 


and  delicate,  and  their  normal  contents  are — Ist^  a  yellowish,  gran- 
ular, semi-fluid  substance;  2dhj^  a  round,  vesicular,  nucleolated  nu- 
cleus, 4^V(T  to  3  oVo  of  an  inch  in  diameter  (and  sometimes  two  of 
these).  Besides  these  (3f%)  fat-drops,  and  (4//J//)  pigment-granules 
are  frequently  to  be  met  with.  The  last  hardly  exceed  y^^^^  of 
an  inch  in  diameter,  are  of  a  yellow  or  brownish-yellow  color,  and 
appear  to  be  chemically  identical  with  the  coloring  matter  of  the 
bile  (p.  101). 


534 


THE   TISSUES. 


These  cells  are  so  arranged  in  the  islets  as  to  a^ypear  to  form  a 
network  by  the  mere  apposition  of  their  flat  surfaces,  without  any 
intermediate  substance  or  investing  coat.  The  meshes  of  the  net- 
work are  mere  perforations  and  passages  for  the  capillary  plexus 
and  the  commencement  of  the  hepatic  vein,  and  are  of  course  con- 
formed to  their  diameters.  The  cells  are  generally  arranged  in 
from  one  to  three  rows  (rarely  four  or  five),  to  form  the  network 
itself  (Fig.  118),  so  that  the  meshes  are  thus  j^^-q  to  g^^  of  an  inch 
apart.  Their  true  relation  to  the  minute  hepatic  ducts  will  be 
specified  on  page  536. 

The  hepatic  ducts  had  been  traced  to  the  margin  of  the  hepatic 
islets  by  KciUiker,  but  not  into  them ;  and  he  suggests  that  the  finest 
ducts  are  open  at  their  extremity,  and  abut  on  the  hepatic  cells,  as 
shown  by  Fig.  118.  Far  more  probable,  however,  was  the  view  of 
Prof.  Leidy  on  this  subject,  viz.,  that  the  hepatic  ducts  commence 
in  the  substance  of  the  islets  as  a  network  of  distinct  tubules,  lined 
by  a  basement-membrane  and  an  epithelium.'    (Figs.  366  and  367.) 


Fig.  366. 


Fig.  367. 


Transverse  section  of  a  lobule  of  the  human  liver, 
showing  the  reticular  arrangement  of  the  bile-ducts  ; 
with  some  of  the  branches  of  the  hepatic  vein  in  the 
centre,  and  those  of  the  portal  system  at  the  periphery. 


A  small  portion  of  the  preceding  section, 
more  highly  magnified,  showing  the  secret- 
ing cells  within  the  tubes.   {Leidy.) 


But  Dr.  Beale's  recent  investigations  on  this  point  seem  quite  con- 
clusive. He  finds  the  hepatic  cells  to  be  arranged  in  lines  radiating 
from  the  centre  of  the  lobule,  as  shown  in  Fig.  368;  though  pre- 
cisely this  appearance  is  presented  only  when  the  section  is  made 
at  right  angles  to  the  small  twig  of  the  hepatic  vein  in  the  centre  of 


'  Researches  into  the  Comparative  Structure  of  the  Livei*,  American  Journal  of 
the  Medical  Sciences,  Jan.  1848. 


THE    LIVER. 
Fig.  3G8. 


535 


Transverse  section  of  hepatic  islets  (horse),  showing  the  secreting  cells  forming  lines  radiating  from 
the  hepatic  vein  (a)  in  the  centre,  towards  the  circumference  (6).  Inj  ected  with  vermilion.  (Dr.  Beale.) 

the  islet.  There  is  "usually  but  one  row  (sometimes  two)  of  cells 
between  the  capillary  vessels.  He  further  ascertained  that  these 
rows  of  cells  are  contained  ivithin  tubes  formed  of  simple  membrane; 
which  is  sometimes  incorporated  with  the  walls  of  the  capillaries, 
and  sometimes  distinct  from  them.  (Fig.  369.)  These  cell-con- 
taining tubes,  therefore,  form  the  network  in  the  substance  of  the 
islet. 

Fig.  369. 


Tubes  of  simple  membrane  containing  the  liver-cells  (pig),  a.  An  injected  specimen,  the  shades 
showing  the  injection,  b.  Cells  and  free  oil-globules  within  the  tube.  c.  Tube  in  which  the  cells 
have  boon  disintegrated. — JIagnifled  200  diameters.    {Dr.  Beale.) 


536 


THE   TISSUES. 


The  precise  connection  of  the  ducts  between  the  lobules,  and  the 
tubes  just  mentioned,  is  as  follows:  Numerous  finer  branches  leave 
the  small  trunk  of  the  duct,  in  the  spaces  between  the  islets,  and 
pass  towards  the  secreting  cells,  without  branching  or  anastomosing 
with  each  other;  and,  pursuing  a  tortuous  course  around  the 
branches  of  the  portal  vein,  pass  at  once  to  the  cell-containing  net- 
work of  tubes  just  described,  and  with  which  they  are  continuous. 
Near  to  the  point  where  the  duct  joins  the  network  of  cell-contain- 
ing tubes,  it  becomes  very  much  narrowed;  being  frequently  g^V^y 


Fig.  370. 


Communications  of  interlobular  ducts,  a.  With  the  cell-containing  tubular  network,  b.  Part  of 
tubes  containing  cells  filled  Tvith  oil  and  free  oil-globules,  c.  Narrowest  portions  of  the  ducts  (pig.) 
The  shaded  parts  are  filled  with  injection. — Magnified  215  diameters.    {Dr.  Beale.) 

of  an  inch,  or  even  less,  in  diameter  in  the  uninjected  state.  Fig. 
370  represents  the  narrowest  ducts  in  tbe  pig,  and  Fig.  371  those 
in  the  human  liver. 

The  epithelium  lining  the  minute  ducts  between  the  islets  (y^'ofj 
of  an  inch  in  diameter)  is  of  the  simple  scaly  variety;  its  cells  being 
far  smaller  than  the  secreting  cells  in  the  network  before  described, 
or  only  about  goVv;  of  ^^^  i^^cli  in  diameter.  Fig.  372  shows  their 
size  compared  with  that  of  the  former.  It  terminates  abruptly 
where  the  secreting  cells  begin.  In  the  ducts  3^^  to  ^\^  of  an  inch 
in  diameter,  the  epithelium  is  more  conoidal;  and  it  becomes  com- 
pletely so  in  those  above  jjo  o^  ^^  inch.  The  latter  also  have  a 
dense  layer  of  areolar  tissue  (corium)  externally  to  the  epithelium 
and  basement-membrane.  The  ductus  communis  choledocJuis,  and 
the  cystic  duct,  have  both  a  mucous  layer  and  a  submucous  areolar 
layer;  the  former  containing  a  few  smootb  muscular  fibres,  but  no 


THE   LIVER. 


537 


special  muscular  coat.  The  gall-bladder  has  a  layer  of  smooth  mus- 
cular fibres  beneath  its  peritoneal  covering.  That  of  the  ox  may 
be  made  to  diminish  its  capacity  one-fourth  by  a  powerful  galvanic 


Fig.  371. 


Fig.  372. 


Fig.  371.  Narrowest  portions  of  bile-duct,  lined  by  its  epithelium,  continuous  into  the  tubes  con- 
taining the  hepatic  cells.  A  venous  capillary  and  a  small  branch  of  the  artery  are  seen  in  section, 
close  to  the  narrow  duct.  The  liver-cells  have  been  destroyed  by  the  reagents  used  in  preparing 
the  specimen.  (Human.) — Magnified  215  diameters.    (Dr.  Beale.) 

Fig.  372.  Terminal  portion  of  interlobular  duct,  containing  its  epithelium,  with  four  hepatic  cells 
to  show  the  comparative  size. 

battery.  [Dr.  Mayer)  Its  mucous  membrane  presents  many  reticu- 
lated, more  or  less  prominent,  folds,  containing  a  capillary  network 
exactly  like  that  of  the  foliaceous  intestinal  villi.  It  has  also  a 
couoidal  epithelium. — Finally,  the  mucous  membrane  of  the  hepatic 
ducts  above  y^-^  of  an  inch  in  diameter  contains  a  multitude  of 
small,  racemose,  yellowish  mucous  glands  {Kblliher)  or  sacculi  [Dr. 
Beale) ;  while  there  are  but  few  in  the  cystic  duct,  and  usually  none 
at  all  in  the  gall-bladder.  Dr.  Beale  finds  these  generally  to  be 
simple  oval  pouches,  arranged  in  two  rows  on  opposite  sides  of  the 
duct,  and  connected  with  its  cavity  by  a  very  narrow  neck,  often 
not  5oVo  of  ^^  inch,  in  diameter.  In  the  larger  ducts  they  are, 
however,  branched,  and  often  run  for  some  distance  in  the  coats  of 
the  duct.  Occasionally  the  branches  of  one  gland  anastomose  with 
those  of  another.  Fig.  373  shows  the  more  simple,  and  Fig.  374 
the  complicated  forms  of  these  pouches  in  the  pig;  where  they  are 
arranged  completely  around  the  duct. 

Many  of  the  smaller  ducts,  about  Jg  of  an  inch  in  diameter,  have 
numerous  csecal  pouches,  arranged  pretty  closely  together,  and 
giving  off  branches  of  simple  membrane  only.  These  are  very 
numerous  in  the  transverse  fissure  of  the  liver,  where  they  form  an 
intricate  network  connected  with  the  larger  branches  of  the  duct. 
They  were  first  noticed,  and  named  vasa  aberrantia,  by  "Weber ; 
and  who  also  described  the  anastomosis  between  the  right  and  left 


538 


THE   TISSUES. 
Fig.  373. 


A  small  lobule,  showing  tlie  duct  branching  upon  the  capsule  (pig).     The  sacculi  of  the  ducts  are 
seen  as  injected.     A  branch  of  the  portal  vein  accompanies  the  duct. 

hepatic  ducts  in  the  transverse  fissure,  by  the  intervention  of  their 
irregular  branches. 

Fig.  374. 


Large  sacculi  or  glauds  in  the  coat.s  of  the  duct.s  (pig).  The  largest  and  most  complicated  at  c, 
wliere  a  smaller  branch  is  coming  off  from  the  main  trunk,  a.  Portion  of  largo  duct.  b.  A  small 
branch  without  glands. — Magnifled  10  diameters.    {Dr.  Becde.) 

Dr.  Beale  considers  these  cavities  or  irregular  branches  "as  little 
reservoirs  in  which  the  bile  in  the  thick-coated  ducts  is  brought 
into  closer  proximity  with  the  numerous  vessels  surrounding  them; 


THE    l.IVER.  539 

bj  which  it  loses  some  of  its  water,  and  probably  undergoes  other 
changes." 

Thus  the  secreting  cells  at  the  surface  of  the  islets  probably  take 
the  most  active  part  in  the  secretion  of  bile,  being  first  reached  by 
the  portal  blood,  and  while  it  also  circulates  more  slowly.  These 
cells  also  first  show  an  increase  of  oil-drops  in  cases  of  fatty  de- 
generation. The  bile  is  formed  by  each  individual  cell,  and  trans- 
ferred, by  the  tube  inclosing  the  row  of  cells,  to  the  ducts  between 
the  islets.  The  very  close  contact  in  which  the  cells  sometimes  lie, 
is  accounted  for  by  the  great  changes  in  bulk  they  are  known  so 
readily  to  undergo.  Hence  the  liver  is  a  true  glancl,  like  the  other 
racemose  glands;  and  not  essentially  distinct  from  them  in  struc- 
ture, as  has  generally  been  asserted. 

The  capillary  network  of  the  islets  completely  fills  the  interspaces 
of  the  tubular  network,  before  described  (Fig.  118).  The  capilla- 
ries average  about  z-qq-q  to  ssVir  of  ^"^  inch,  in  diameter;  being 
somewhat  less  than  the  rows  of  the  cells  in  the  tube-network.  The 
meshes  between  the  vessels  of  course  correspond  in  diameter  with 
that  of  the  columns  of  the  cells,  being  ^oVo  ^o  s^o  of  ^^  inch,  A 
transverse  section  of  the  islets  (in  the  pig),  is  shown  by  Fig.  363, 
where  the  formative  radicles  of  the  intra-insular  hepatic  vein  is 
seen  in  the  centre,  and  the  capillary  communications  on  the  other 
hand  with  the  vena  portee,  in  the  perimetral  portion.  The  latter, 
however,  even  in  the  pig,  does  not  form  a  complete  ring  round  each 
lobule.  The  blood  probably  moves  more  slowly  in  the  outer  part 
of  the  capillary  network ;  where  it  is  more  richly  charged  with  the 
constituents  of  the  bile.  The  external  cells  also  usually  contain 
the  m.ost  fat ;  the  central  the  most  colored  granules. 

The  hepatic  artery  also  terminates  in  the  outer  part  of  the  capil- 
lary plexus  of  each  islet,  with  the  vena  port^e,  it  having  previously 
supplied  the  walls  of  the  vessels,  and  the  intra-insular  spaces  (the 
capsules  of  the  lobules,  in  the  pig).  In  regard  to  the  lymphatics  and 
nerves  of  the  liver,  the  works  on  descriptive  anatomy  may  be  con- 
sulted. That  some  twigs  from  the  diaphragmatic  nerve  are  sent 
to  this  organ,  was  first  announced  by  Luschka. 

Dr.  Beale  finds  the  chemical  composition  of  the  liver  to  be  as  fol- 
lows : — 

Water 68.58 

Solid  residue 31.42 


540 


THE   TISSUES. 

Fatty  matter 

,           ,           , 

3.82 

Albumen 

.           . 

4.67 

Alkaline  salts 

. 

1.17 

Earthy  salts 

. 

.33 

Extractive  matter 

5.40 

Vessels,  &c.,  insolu 

ble  in  water 

16.03 

y      31.42 


Function  of  the  Liver. — 1.  The  liver  secretes  the  bile,  whose  pro- 
perties have  already  been  specified  (p.  212).  And  all  analogy  war- 
rants the  idea  that  it  is  secreted  by  the  true  hepatic  cells  lying  in 
the  meshes  of  the  portal-hepatic  plexus,  and  which  are  contained  in 
the  tubes  which  have  been  described.  It  is  also  very  certain  that 
the  bile  is  formed  in  the  cells  and  not  merely  eliminated  from  the 
blood  (p.  211).  2.  But  the  liver  also  forms  sugar,  as  has  already 
been  shown  (p.  71);  and  probably  its  parenchymal  cells  are  the  agents 
employed  in  its  formation.  3.  Again,  the  liver  produces  a  change 
in  the  alimentary  substances  (albumen,  &c.),  while  traversing  it 
from  the  vena  portJB,  after  being  first  absorbed  into  the  vessels  of 
the  intestinal  villi.  It  even/orws  fat  as  well  as  sugar,  when  neither 
are  contained  in  the  food ;  and  thus  becomes  a  sort  of  equilihrator  of 
the  function  of  hcematosis,  or  the  development  of  blood. 

Of  its  pathological  conditions,  fatty  degeneration  has  already  been 
described  at  some  length  (p.  311,  5). 

In  cirrhosis  of  the  liver,  there  is  an  enormous  increase  of  the  areolar 
tissue  inclosing  the  vascular  trunks  (except  the  hepatic  vein)  and 
the  hepatic  ducts;  and  the  individual  islets  may  become  prominent, 
or  even  form  isolated  lobules.  Since  also  this  increase  of  the 
connective  tissue  is  consequent  upon  the  organization  of  plasma 
exuded  by  an  inflammation  of  Glisson's  capsule,  and  the  new  for- 
mation subsequently  contracts — the  liver  is  thus  rendered  more 
solid  and  smaller ;  the  true  hepatic  substance  also  becoming  atro- 
phied, or  in  part  disappearing. 

In  jaundice,  the  pigment-granules  are  abnormally  increased  in  the 
hepatic  cells;  they  sometimes  completely  filling  the  latter. 

For  its  other  pathological  conditions,  reference  must  be  had  to  the 
treatises  on  pathological  anatomy. 

2.  The  Pancreas. 
The  pancreas  is  a  compound  racemose  gland,  so  similar  in  its 
minute  structure  to  the  salivary  glands,  that  only  its  peculiarities 
will  be  here  described.  The  terminal  caeca  of  the  pancreatic  duct 
are  g/,^  to  ^^^  of  an  inch  in  diameter,  and  usually  rounded,  and 
are  lined  by  a  simple  scaly  epithelium  whose- cells  are  frequently 


THE    URINARY   APPARATUS.  541 

remarkable  for  their  number  of  fat-granules.  The  pancreatic  duct 
is  lined  by  a  mucous  membrane,  an  offset  from  that  of  the  duode- 
num, with  a  simple  conoidal  epithelium ;  and  presenting  many 
small  racemose  glands — probably  analogous  to  the  mucous  glands 
of  the  bile-ducts.  (KbWcer.) 

The  bloodvessels  are  distributed  precisely  as  those  of  the  parotid 
gland  ;  while  the  lymphatics  are  more  numerous.  The  nerves  only 
accompany  the  vessels,  and  rise  from  thg  great  sympathetic. 

The  secretion  of  the  pancreas  is  of  the  greatest  importance  to 
the  function  of  digestion,  as  has  been  explained  on  page  213. 


CHAPTER    XIV. 

THE    URINARY    APPARATUS. 

The  urinary  organs  are  the  kidneys,  the  ureters,  the  bladder,  and 
the  urethra.  The  mucous  membrane  lining  the  last  three,  forms 
the  urinary  passages  ;  while  that  of  the  uriniferous  tubes  of  the  kid- 
neys is  the  seat  of  the  secretion  itself  The  urinary  passages  will 
be  first  described,  and  then  the  substance  of  the  kidney. 

1.  The  urethra  of  the  male  will  be  described  with  the  sexual  organs 
(p.  550).  That  of  the  female  has  a  reddish  mucous  membrane,  with 
a  compound  scaly  epithelium,  and  a  quite  vascular  corium.  The 
latter  also  contains,  especially  near  the  bladder,  a  certain  number 
of  racemose  mucous  glands  (Littre's  glands.  Fig.  380),  like  those  of 
the  bladder,  except  that  ihey  are  larger  (sometimes  even  -^^  of  an 
inch  in  diameter),  and  more  closely  placed.  It  has  a  tunic  of  lon- 
gitudinal and  transverse  smooth  muscular  fibres,  intermixed  with 
areolar  tissue;  and  outside  of  this,  the  musculus  urethralis  {Kdlliker\ 
consisting  principally  of  transverse  fibres.  In  the  submucous  areo- 
lar tissue  is  a  plexus  of  veins,  which  has  been  incorrectly  described 
as  a  corpus  spongiosum. 

2.  The  bladder  has,  externally  to  its  lining  mucous  membrane, 
two  layers  of  smooth  muscular  fibres:  1,  an  internal,  consisting  of 
oblique  and  transverse  fasciculi,  incompletely  covering  the  mucous 
membrane  from  their  reticular  arrangement,  but  constituting  a 
strong  circular  layer  at  the  neck  of  the  bladder  (the  sphincter  ve- 


542  THE   TISSUES. 

sicae) ;  and  2,  an  external  layer  of  parallel  longitudinal  fasciculi  (the 
detrusor  urince). 

The  mucous  membrane  is  pale,  smooth,  and  rather  thick,  except 
where  the  vesical  triangle  is  situated ;  and  most  vascular  at  the  fun- 
dus and  the  neck  of  the  bladder.  Its  nerve-fibres  are  principally 
confined  to  the  same  parts,  are  dark-bordered,  and  both  fine  and  of 
medium  size.  Its  epithelium  generally  approaches  the  compound 
scaly  kind,  and,  like  that  (5f  the  pelvis  of  the  kidney,  is  remarkable 
for  the  diversity  in  form  and  size,  of  its  cells — the  deeper  being 
usually  elongated,  and  the  superficial  rounded,  polygonal,  or  flat- 
tened. A  conoidal  epithelium,  however,  exists  near  the  urethra 
and  the  orifices  of  the  ureters.  The  corium  is  level  (presenting  no 
papillaj),  and  shows  isolated  or  aggregated  simple  racemose  mucous 
glands  in  the  neck  of  the  bladder  and  towards  the  fundus.  These 
are  3^0  to  ^^  of  an  inch  in  diameter,  and  their  orifices  are  g^o  to 
2^^  of  an  inch.  They  have  a  conoidal  epithelium.  In  pathologi- 
cal conditions  these  are  sometimes  enlarged  and  filled  with  whitish 
mucous  plugs.  {Virchow.)  There  is  an  abundant  submucous  layer 
of  areolar  tissue,  except  over  the  vesical  triangle;  and  which  is 
thrown  into  numerous  folds  when  the  bladder  contracts. 

3,  The  ureters,  including  also  the  pelvis  and  the  calices  of  the 
kidney,  are  composed  of  an  external  fibrous  coat,  a  middle  mus- 
cular coat,  and  a  mucous  membrane.  1.  The  fibrous  coat  is  com- 
posed of  areolar  tissue,  and  where  the  calices  surround  the  j^a^j/Z/re, 
is  continuous  with  the  fibrous  coat  of  the  kidney.  2.  The  muscular 
tunic  consists  of  an  external  longitudinal,  and  an  internal  trans- 
verse layer  of  smooth  fibres;  longitudinal  fibres  being  also  added 
to  the  inner  layer  towards  the  bladder.  The  two  muscular  layers 
are  as  thick  in  the  pelvis  of  the  kidney  as  in  the  ureters  lower 
down ;  becoming  thinner  in  the  calices,  and  ceasing  where  the  latter 
are  inserted  into  the  papillas.  3.  The  mucous  membrane  is  thin 
throughout,  tolerably  vascular,  without  glands  or  papillae,  and  is 
continued  upon  the  renal  papillae.  Its  epithelium  is  the  compound 
scaly  variety  like  that  of  the  bladder,  and  is  5^^  to  ^^^  of  an  inch 
thick.     The  cells  frequently  contain  two  nuclei. 

Structure  of  the  Kidney. 
The  kidney  is  made  up  of  8  to  15  lobules  (pyramids  of  Malpighi), 
each  inclosed  in  an  investment  of  areolar  tissue;  and  which  are  all 
invested  together  by  the  fibrous  capsule  of  the  kidney.     Outside  of 


STRUCTURE   OF  THE   KIDNEY.  543 

the  latter  is  a  layer  of  loose  areolar  tissue  abounding  in  fat-cells, 
improperly  termed  the  adipose  capsule.  The  structure  of  the  kid- 
ney is,  therefore,  but  the  repetition  of  that  of  each  lobule. 

Each  lobule  is  of  a  pyramidal  form,  the  base  presenting  on  the 
surface  of  the  kidney,  and  the  apex  at  the  hilus;  the  outer  por- 
tion, about  half  an  inch  thick,  being  more  vascular,  and  constituting 
the  cortical  portion  of  the  kidney,  while  the  remaining  part  con- 
tains no  Malpighian  bodies,  but  consists  principally  of  the  urinifer- 
ous  tubes,  and  is  termed  the  medullary  or  tubular  portion.  The 
vascular  portion,  however,  also  gives  off  processes  inward,  ex- 
tending even  to  the  hilus  (the  columns  of  Bcrtini). 

1,  The  tuhuU  uriniferi  of  the  kidney  commence  in  the  papilke  of 
each  lobule  {i.  e.  the  prominent  part  constituting  the  apex  of  the 
lobule),  by  from  200  to  500  orifices  ^^^  to  X20  of  ^■i"^  ^i^-ch  in  dia- 
meter, scattered  over  its  surface;  and  traverse  the  pyramids  in  close 
contiguity  (tubes  of  Bellini).  Each  tubule  in  its  course  divides  at 
least  as  many  as  ten  times,  and  usually  at  very  acute  angles,  into 
two,  or  more  rarely  into  three  or  four  smaller  branches,  diverging 
from  each  other,  somewhat  like  the  dentinal  tubuli;  and  thus  giving 
a  greater  diameter  to  the  lobules  towards  the  exterior.  Vessels 
are  also  interpolated  between  them  at  regular  distances  as  they  pro- 
ceed outwards.  Arriving  in  the  cortical  substance  they  become 
curved  in  their  course  {tubuli  contorti),  appearing  at  first  sight  to  be 
inextricably  interwoven,  but  ultimately  terminating,  as  discovered 
by  Bowman,'  in  a  dilated  extremity  yoVo  of  an  inch  in  diameter, 
containing  a  vascular  plexus  of  a  peculiar  kind — the  Malpighian 
body.     (Figs.  875,  130,  and  377.) 

The  tubuli  contorti  (or  convoluted  portions  of  the  tubes)  are,  how- 
ever, actually  arranged  in  columnar  masses  ~j^  to  ^\  of  an  inch  wide 
(the  pyramids  of  Ferrein),  extending  through  the  entire  cortical 
substance;  and  here  they  freely  anastomose  with  each  other.  The 
number  of  the  tubuli  contorti  corresponds  with  that  of  the  Mal- 
pighian bodies.  Huschke  calculates  that  each  "pyramid  of  Fer- 
rein" contains  200  tubuli,  and  that  there  are  700  of  these  pyramids 
in  a  single  lobule,  or  pyramid  of  Malpighi.  Assigning  15  of  the 
latter  to  each  kidney,  it  would  contain  2,100,000  tubuli  contorti, 
and  as  many  Malpighian  bodies.  Todd  and  Bowman  maiatain 
that  the  urine  is  secreted  only  in  these  convoluted  portions  of  the 
tubes.     (Figs.  375,  in,  and  130,  1  and  2.) 

'  In  1842. 


544 


THE   TISSUES. 


The  tubuli 


Fig.  375. 


uriniferi  are  everywhere  composed  of  a  simple  co- 
noidal  epithelium  resting  upon 
a  strong  basement- membrane, 
3  71)  o(T  to  T6¥(T7  of  an  inch  thick, 
external  to  which  is  no  distinct 
corium  but  merely  the  stroma, 
consisting  of  a  firm  transparent 
substance  containing  small  gra- 
nular cells  {Todd  and  Bowman) ; 
which,  everywhere  in  the  lobule, 
connects  its  various  structural 
elements  together.  (Fig.  376.) 
Being  at  the  commencement  in 
the  papillae  -g^-^  to  X20  of  3,n  inch 
in  diameter,  their  branches  are 
soon  but  TsVo  to  g^8  of  an  inch; 
but  in  the  pyramids  of  Ferrein 
they  again  expand  to  g  J^  to  g^ij, 
and  in  the  cortical  substance  to 
■gj^  of  an  inch  or  less;  though 
again  somewhat  constricted  just 
before  they  end  in  the  dilatation 
receiving  the  Malpighian  bodies, 
,Vn   of  an   inch  wide. 


200    to 


T2(T0 


The  nucleated  epithelial  cells  are 
also  larger  in  the  tubuli  contorti 
Ct^Vo  to  To^iTTT  of  an  inch  wide, 
and  3^'oo  to  2  4V¥  of  an  inch 
thick);  while  in  the  straight 
portion  of  the  tubules  they  are 
only  one-half  as  wide,  and  ^^Vtt 

Vertical  section  through  a  portion  of  a  pyramid  and  the  cortical  substance  belonging  to  it,  of  an 
injected  ral.bit'8  kidney.  The  figure  is  half  diagrammatic.  The  vessels  are  represented  on  the  left 
side  and  on  the  right  the  course  of  the  tubuli  uriniferi.  a.  Arterias  interlobulares  with  the  Mal- 
pighian bodies  (6),  and  their  vasa  afferontia.  c.  Vasa  efferentia.  d.  Cortical  capillaries,  e.  Vasa 
efferentia  of  the  outermost  bodies,  proceeding  to  the  superficial  capillaries.  /.  Vasa  efferentia  of  the 
innermost  tufts  continuous  with  the  arteriola)  rect»  (fir,  g,  g).  h.  Capillaries  of  the  pyramids  which 
are  formed  out  of  the  latter,  i.  A  venula  recta,  commencing  at  the  papilla,  k.  Commencement  of  a 
straight  canal  at  the  papilla.  I.  Divisions  of  the  same.  m.  Convoluted  tubes  in  the  coriox,  their 
whole  course  not  shown,  n.  The  same  at  the  surface  of  the  gland,  o.  Their  continuation  in  the 
straight  tubules  of  tho  cortex,  p.  Their  connection  with  the  Malpighian  capsules.-Magnifled  30 
diameters.    {KoUiker.) 


STRUCTURE   OF   THE   KIDNEY. 


545 


of  an  inch  thick,     Thes3  cells  have  also  clear,  non-granular  con- 
tents; while  those  of  the  tubuli  contorti  contain,  besides  the  usual 

Fig  376. 


Section  of  the  cortical  substance  of  tlie  human  kidnoy.  a,  a.  Tubuli  uriniferi  divided  trans- 
versely, showing  the  subconoidal  epithelium  in  their  interior,  b.  Malpighian  capsule;  a,  its  affer- 
ent branch  of  the  renal  artery  ;  6,  its  tuft  of  capillaries  ;  c,  c,  secreting  plexus  (of  vessels)  formed  by 
its  efferent  vessels  ;  d,  d,  fibrous  stroma. 

round  nuclei,  a  finely  granular  albuminous  {Kdlliker)  substance  in 
the  fluid  contents,  and  generally  some  dark  oil-drops,  and  more 
rarely,  granules  of  yellow  pigment.  (Fig.  132^  A  &  B.)  The  last 
cells  alone  probably  secrete  the  urine.  [Todd  and  Bowman.) 

2.  The  vascular  (cortical)  portion  of  each  lobule  consists  of  the 
tubuli  contorti,  just  described,  the  Malpighian  bodies,  the  vessels 
carrying  blood  to  and  from  the  latter,  and  the  stroma  of  embryonic 
areolar  tissue  connecting  all  these  elements  together.  The  Malpi- 
ghian bodies  extend  to  within  g-^-^  of  an  inch  of  the  surface  of  the 
kidney  on  tbe  one  hand,  and  in  the  columns  of  Berlini  even  to  the 
hilus  of  the  kidney  on  the  other.  Each  of  these  is  a  rounded  mass 
(glomerulus),  consisting  of  a  close  convolution  or  tuft  of  capillaries 
30V0  to  T5V0  of 'T-n  inch  in  diameter;  inclosed  in  a  capsule  and  sup- 
plied by  an  artery  {yas  ajferens)^  T5V0  ^o  g-Jo  of  an  inch  in  diameter. 
This  convolution  of  vessels  is  received  into  the  dilated  extremity 
of  a  hihuhis  contortiis ;  and  its  capsule  is  apparently  the  continuous 
basement-membrane  of  the  tubulus,  somewhat  thickened.  Thus 
the  Malpighian  body  is  virtually  inclosed  in  the  extremity  of  the 
tubulus;  and  it  amounts  to  the  same  thing,  practically,  if  it  be  said 
that  the  tubulus  ends  like  the  larger  closed  extremity  of  a  retort, 
after  having  first  inclosed  the  Malpighian  body.  (Figs.  377,  and  131.) 
A  vessel  also  emerges  from  the  tuft  within,  through  the  capsule  (the 
vas  eflferens) — not  a  vein,  however,  as  might  be  expected :  the  pre- 
35 


546 


THE   TISSUES. 


Fig-  377.  cise  arrangement  of  the  ves- 

sels being  as  follows :  The 
artery  divides  at  once  on 
entering  the  coil  into  from 
5  to  8  branches,  and  each 
of  these  into  a  bundle  of 
capillaries,  which,  though 
much  interlaced  and  convo- 
luted, do  not  anastomose; 
and  ultimately  merge  into 
the  vas  ejferens  in  the  way 
in  which  they  were  first 
formed.  Generally,  the  two 
vessels  enter  and  quit  the 
glomerulus  near  together, 
and  opposite  the  commence- 
ment of  the  tubulus;  and 
the  capillary  loops  and  con- 
volutions are  always  situat- 
ed exactly  at  its  commence- 
ment. The  vas  eff'erens  after 
emerging  from  the  capsule 

Relations  of  Malpighian  tufts  to  the  arterialbranches  „C     +]-,a      ATalnio"llian      brtdv 
and  the  cortical  portion  of  the  uriniferous  tubes  (man).  r   o  J  ' 

a.  Arterial  branch  with  its  terminating  twigs,  the  injec  prOCCcds  aS  an    artery  for    a 

tion  having  only  partially  filled  the  tuft  at  «.     It  has  ghort  distaUCC,  and    then  di- 
entirely  filled,   ^,  and  passed  out  through  the  efferent  ' 

vessel,  e,f.    It  has  burst  into  the  capsule  at  y,  entered  yidcS  intO  tWO  SCtS  of  Capil- 

the  tube,  t,  and  filled  the  efferent  vessel,  c,  /.     At  J*  it  -i       •  , -i  •  -i 

has  extravasated,  and  passed  along  the  tube.     At  m  the  i^rieS       tnC  OHC  gOlUg  tO  tDC 

injection  has  escaped  from  the  capsule  to  a  limited  ex-  COrtical    DOl'tion    tO    CUCOm- 
tent.     (Magnified  4.5  diameters.)  ,  i      t 

pass  the  tubuli  contorti  on 
all  sides  in  a  rich  network  which  is  continuous  through  the  whole 
cortical  substance — and  the  other  taking  a  straight  course  and  with 
but  few  branches,  between  the  straight  tubes,  and  in  the  whole  cir- 
cumference of  the  pyramids,  even  to  the  papillae,  in  which  they  are 
continuous  with  the  proper  capillaries  of  these  parts.     (Fig.  378.) 

Kcilliker  describes  the  epithelium  of  the  tubuli  contorti  as  in- 
closing the  glomerulus;  while  at  the  same  time  the  projecting  free 
portion  of  the  glomerulus  is  covered  by  epithelium.  This  has  also 
been  recently  demonstrated  in  a  very  ingenious  manner  by  Dr. 
Isaacs,  of  this  city ;  though  Todd  and  Bowman  still  believe  that 


VESSELS   AXD   NERVES   OF   THE    KIDNEYS. 


547 


the  "  vessels  are  bare  within  the  capsule.'"  KciUiker  describes  the 
epithelium  as  existing  everywhere  between  the  Malpighian  tuft 
and  its  capsule,  except  where  the  affer- 
ent and  efferent  arteries  penetrate.  The 
ciliary  motion,  described  by  Bowman,  at 
the  junction  of  the  Malpighian  bodies 
and  the  tubuli  contorti,  exists  in  reptiles 
and  fishes ;  but  not  in  man  or  other 
mammalia. 

Vessels  and  Nerves  of  the  Kidney. 

The  branches  of  the  renal  artery  enter 
the  cortical  substance  interposed  between 
the  pyramids  (columns  of  Bertini),  and 
in  the  boundaries  of  the  latter  repeatedly 
dividing,  form  a  delicate  ramification 
without  anastomoses  around,  each  pyra- 
mid. From  this  on  the  side  towards  the 
cortical  substance,  smaller  arteries  arise, 
mostly  at  right  angles,  which,  after  seve- 
ral divisions,  give  off  the  interlobular  ar- 
teries (3^0  to  Jo  0  of  an  incb  in  diameter), 
Avhich  run  outwards  in  a  straight  course 
between  the  cortical  fasciculi,  or  pyra- 
mids of  Ferrein.     And,  finally,  the  last 

give  off  on  one,  two,  three,  or  four  sides,  a  great  number  of  the 
arteria  afferentia  of  the  Malpighian  bodies  already  described.  In- 
deed, except  a  few  branches  to  the  capsule  of  the  kidney,  all  the 
interlobular  arteries  terminate  in  the  formation  of  the  vascular 
tufts.  (Figs.  130  and  377.) 

The  renal  veins  commence  in  two  situations :  Is;!,  at  the  surface 
of  the  kidney ;  and,  2dly^  at  the  apices  of  the  papillae.  In  the  first 
situation,  minute  veins  are  formed  from  the  outermost  part  of  the 
capillary  plexus  of  the  cortical  substance,  and  surround  each  bundle 
-of  Ferrein ;  and,  between  the  latter,  unite  in  a  stellate  manner  into 
larger  roots,  or,  extending  over  several  bundles,  connect  into  larger 
trunks.  These,  however,  all  unite  to  form  the  interhhuJar  veins 
which,  accompany  the  arteries  of  that  name,  before  described;  and 


Malpigliian  tuft  from  near  the 
tase  of  one  of  the  medullary  cones. 
CT.  Arterial  branch  ;  a/,  afferent  ves- 
sel, in.  Malpighian  tuft.  ef.  Effer- 
ent vessel ;  b,  its  branches,  entering 
the  medullary  cone.  (Magnified  70 
diameters.) 


'  The  Physiological  Anatomy  and  rhysiology  of  Man.     Tart  iV.,  sect.  2,  p.  4S0. 


54:8  THE   TISSUES. 

larger  branches  finally  terminate  in  the  wider  arclied  venous  ranii- 
fications  encompassing  the  pyramids  (lobules).  The  veins  of  the 
latter  commence  in  a  beautiful  plexus  surrounding  the  orifices  of 
the  uriniferous  tubes  on  the  papillae,  and,  ascending  with  the  arte- 
ries of  the  pyramids  between  the  tubuli  recti,  also  terminate  in  the 
ramifications  just  named. 

There  are,  proportionally,  but  few  lymphatics  in  the  kidney,  ac- 
companying the  bloodvessels  as  far  as  the  interlobular  branches. 

The  nerves  also  (from  the  cardiac  plexus)  form  a  plexus  around 
the  arteries,  to  their  interlobular  subdivisions.  How  and  where 
they  terminate  is  unknown. 

Of  the  chemical  composition  of  the  kidney  but  little  is  known. 
Frerichs  found  from  72  to  73.70  per  cent,  of  water,  and  28  to  26.80 
of  solid  matter.  The  fat  amounted  to  from  .63  to  1  per  cent.,  or 
even  1.86  {Owen  Bees)]  but  the  greater  part  of  the  solid  residue  is 
probably  albumen  from  the  epithelial  cells  (p.  114,  1).  Dr.  Beale 
finds  76.45  of  water,  and  23.55  of  solid  matter;  viz.,  fatty  matter 
containing  much  cholesterine,  .939;  watery  extractive,  5.84;  fixed 
alkaline  salts,  1.01 ;  earthy  salts,  .396;  albumen,  vessels,  &c.,  15.365. 

Function  of  the  Kidney. 

The  kidney  secretes  the  urine ;  for  an  account  of  which  see  pages 
214-22. 

It  is  pretty  certain  that  much  of  the  water  in  the  urine  is  merely 
a  transudation  from  the  Malpighian  bodies;  while  the  peculiar  ele- 
ments of  this  secretion  are  secreted  by  the  epithelial  cells  of  the 
uriniferous  tubes,  and  mainly  at  least  of  the  contorted  portion.  It 
is,  however,  not  probable  that  a  rupture  of  the  epithelial  cells  is 
necessary,  that  their  contents  may  become  free  in  the  straight  por- 
tion of  the  uriniferous  tubes;  and  hence  the  same  cell  may  continue 
to  secrete  longer  than  has  usually  been  supposed.  {T.  and  B.y 

Development  of  the  Kidney. 

The  urinary  passages  are  developed  as  an  offset  from  the  lower 

extremity  of  the  intestine;  the  kidneys  being  solid  at  first,  like  the 

salivary  glands.     The  tubuli  are  at  first  composed  solely  of  a  solid 

scries  of  cells,  without  any  basement-membrane.    Subsequently  the 

'  Dr,  Isaacs,  of  this  city,  lias  recently  read  a  paper  before  the  New  York  Academy 
of  Medicine,  maintaining  that  the  urine  is  secreted  also  by  the  Malpighian  bodies. 
As  it  is  not  yet  published,  we  cannot  state  the  grounds  of  this  opinion. 


PATUOLOGICA.L    STATES    OF   THE    KIDNEY.  549 

latter  appears,  and  tlie  tubuli  become  rapidly  longer  and  convoluted. 
The  Malpighian  bodies  are  originally  merely  the  solid  thickened 
extremities  of  the  tubuli,  the  interior  cells  of  which  subsequently 
become  the  capillary  coil.  In  the  new-born  infant,  the  tubuli  are 
one-third  as  large  as  in  the  adult,  and  the  whole  kidney  one-half  as 
large.  [Hariing)     Therefore  no  tubules  are  formed  after  birth. 

The  suinarenal  glands  will  be  described  in  connection  with  the 
blood-vascular  glands  (p.  592),  since  they  appear  to  have  no  phy- 
siological connection  with  the  kidneys. 

Pathological  States  of  the  Kidney. 

1.  The  epithelial  cells  may  contain  abnormal  contents;  e.  g.  an 
increased  amount  of  fat-drops,  constituting  fatty  degeneration  of  the 
kidney  (p.  310,  4),  with  or  without  pigment-granules;  also  colloid- 
like bright-yellow  masses  are  sometimes  found  in  the  cells,  when 
they  generally  dilate  into  slender  cysts,  ^Itr  to  y4^  of  an  inch  long, 
and  which  at  length  burst  and  discharge  the  colloid  substance  into 
the  tubuli,  and  then  into  the  urine.  Cysts  may  also  be  formed  b}^ 
partitions  of  the  tubuli  contorti,  finally  separating  their  extremities 
from  the  portions  below  in  the  pyramids.  The  epithelial  cells  be- 
come detached  in  acute  desquamative  nephritis. 

2.  The  hasement-memhrane  sometimes  becomes  much  thickened 
(to  T3^oo  to  goVo  of  ao-  inch),  and  presents  close  transverse  striee 
on  its  inner  surface. 

3.  The  Maljnghian  bodies  may  expand  into  cysts  containing  the 
atrophied  glomerulus  and  a  clear  fluid. 

4.  As  abnormal  contents  (p.  215),  the  tubuli  may  contain  blood, 
fibrine,  the  colloid  substance  before  mentioned,  concretions  in  the 
straight  tubuli,  principally  of  carbonate  and  phosphate  of  lime;  and 
of  uric  acid  salts,  in  the  new-born  infant,  giving  the  pyramids  a  bril 
liant  gold-yellow  color.  In  Bright's  disease,  exudations  into  the 
tubuli  first  remove  the  epithelium,  after  which  they  become  atro- 
phied, or  altogether  disappear;  or  become  filled  with  a  fatty  broken- 
up  exudation,  and  dilated  into  minute  nodosities  or  granulations. 

5.  In  inflammation  of  the  kidney,  the  stroma  often  becomes  so 
much  condensed  by  the  exudation  as  more  or  less  to  compress  the 
tubuli.     Often,  also,  the  exudation  becomes  organized  into  embry- 

Fig.  379. 


A.    UriniforoUS  tuhr  rnmuuiiii-;  a  uouio^rurous  cast. 


550  THE    TISSUES. 

onic  areolar  tissue;  producing  atrophy  of  the  Malpighian  bodies 
by  its  pressure,  and  thus  interfering  with  the  functions  of  the  gland. 
6.  The  casts  of  the  uriniferous  tubes,  occurring  in  various  con- 
ditions of  the  kidney,  have  already  been  noticed  (Figs.  123— i,  and 
p.  215).     Another  form  is  also  shown  by  Fig.  379. 


CHAPTER    XV. 


THE    SEXUAL   ORGANS. 


I.  Sexual  Apparatus  of  the  Male. 

The  male  sexual  organs  are:  1,  The  testes;  2.  The  vasa  defe- 
rentia;  3.  The  vesiculte  seminales  and  ejaculatory  ducts;  4.  The 
penis,  including  the  urethra  and  the  accessory  glands  (Cowper's  and 
the  prostate).  The  mucous  membrane  of  the  urethra,  prolonged 
through  the  vesicula  seminalis  and  the  vasa  deferentia  to  the  semi- 
niferous tubes  of  the  testis,  constitutes  the  genital  passages  of  the 
male. 

1.  The  urethra  is  a  canal  of  mucous  membrane,  supported  through- 
out its  spongy  portion  by  the  corpus  spongiosum  ui'ethrce,  and  in  the 
prostatic  by  the  prostate  gland;  while  the  membranous  portion,  so 
called,  is  an  independent  canal.  The  corpus  spongiosum  is  essen- 
tially of  the  same  structure  as  the  corpus  cavernosum  penis,  next  to 
be  described ;  except  that  its  investing  fibrous  membrane  is  much 
thinner  and  has  more  elastic  fibres,  the  intertrabecular  spaces  are 
smaller,  and  the  trabeculse  are  smaller  and  richer  in  elastic  fibres 
beneath  their  epithelium.  It  is  also  invested  externally  by  a  layer 
of  smooth  muscular  fibres,  and  expands  into  the  glans  penis  at  its 
free  extremity. 

The  mucous  membrane  of  the  prostatic  and  membranous  por- 
tions contains  smooth  muscular  fibres,  both  longitudinal  and  trans- 
verse, though  less  developed  in  the  membranous  portion ;  and 
outside  of  these,  in  the  latter,  are  the  striated  fibres  of  the  accelerator 
urince  muscle.  Smooth  fibres  also  exist  here  and  there  in  the  sub- 
mucous tissue  of  the  spongy  portion,  and  a  complete  muscular  tunic 
formed  of  them  lies  in  contact  with  the  corpus  spongiosum  on  its 


SEXUAL   APP.A]{ATUS   OF   THE   MALE. 


551 


inside,  towards  the  mucous  membrane,  and  which  meets  the  external 
muscular  layer  at  the  lips  of  the  penis.  {Hancock.) 

The  epithelium  of  the  urethra  is  the  compound  conoidal,  consist- 
ing of  two  or  three  layers  of  cells.  In  the  anterior  half  of  the  fossa 
Malpighii  are  papilUe  ^  J^  of  an  inch  long,  and  a  scaly  epithelium 
^  l-^  of  an  inch  thick.  Kacemose  mucous  glands  are  found  (Littre's 
glands)  in  the  spongy  and  membranous  portions,  of  3^^  to  ^V  of  an 
inch  (Fig.  380);  while  in  the  prostatic  portion  are  minute  mucous 
follicles,  like  those  of  the  neck 
of  the  bladder  (p.  542).  The 
epithelium  both  of  the  coeca  of 
Littre's  glands  and  of  the  ex- 
cretory ducts  (j'.j  to  Y^3  of  an 
inch  long)  is  the  simple  conoid- 
al, approaching  the  scaly  in  the 
first  position.  The  minute  in- 
constant fossae  of  the  mucous 
membrane,  called  lacunce,  con- 
tain nothing  of  a  glandular  na- 
ture. {Kolliker)  Coiuper^s  glands 
are  also  compound  racemose 
mucous  glands,  and  hence  have 
a  structure  like  the  salivary  glands.  The  delicate  membrane  in- 
vestins:  them,  as  well  as  the  fibrous  stroma  in  their  interior  and 
their  excretory  ducts  -^^^  of  an  inch  wide,  are  well  supplied  with 
smooth  muscular  fibres.  A  simple  conoidal  epithelium  lines  the 
ducts,  and  a  scaly,  the  terminal  ceeca. 

The  penis  is  essentially  made  up — Is/,  of  the  urethra,  as  described, 
with  its  spongy  body  invested  by  a  layer  of  smooth  muscular  fibres; 
and,  2dly,  the  two  corpora  cavernosa — with  its  investing  fascia,  skin, 
vessels,  nerves,  &c.  The  corpora  cavernosa  are  two  cylindrical  bodies 
rising  from  the  rami  of  the  ischium,  and  uniting  under  the  sym- 
physis pubis,  though  there  is  between  them  an  incomplete  septum; 
and  consisting  of  a  special  fibrous  membrane  and  the  internal 
spongy  tissue.  The  former  is  composed  of  white  fibrous  tissue  with 
numerous  elastic  fibres,  and  is  o^^  of  an  inch  thick;  investing  the 
cavernous  bodies  externall}^,  and  giving  oft'  the  septum  between 
them,  as  a  thin  lamella,  partially  broken  up  into  separate  fibres  and 
laminae.  Within  it  lies  the  reddish  spongy  substance,  consisting  of 
innumerable  fibres,  bars,  and  laminas^  united  into  a  fine  meshwork 


'filand  of  Littre,"  from  the  fossa  Morgagnii 
man. — Magnified  500  diameters.  (KiUiker.) 


552 


THE   TISSUES. 


(the  trabeculse);  and  the  minute  rounded  angular  cavities  bounded 
bj  the  latter,  and  communicating  on  all  sides.  These  cavities  (the 
venous  sinuses  of  the  cavernous  body)  are  all  lined  by  a  delicate 
scaly  epithelium,  which  often  does  not  admit  of  being  detached;  and 
are  naturally  filled  with  venous  blood.  The  trabecuke  are  composed 
of  collagenous  and  elastic  tissue  in  nearly  equal  proportions,  toge- 
ther with  smooth  muscular  fibres ;  and  in  many  of  them  larger  or 
smaller  arteries  and  nerves  are  inclosed.  The  fascia  penis  incloses 
the  corpora  cavernosa  from  the  root  of  the  penis  to  the  glans, 
abounds  in  elastic  tissue,  and  contributes  to  the  formation  of  the 
suspensory  ligament  of  the  penis;  extending  from  its  dorsum  to 
the  symphysis  pubis,  and  containing  much  elastic  tissue.  External 
to  this  is  the  subcutaneous  areolar  tissue,  containing  a  layer  of 
smooth  muscular  fibres  continued  from  the  dartos  to  the  prepuce; 
and  finally  the  very  delicate  skin,  whose  peculiarities,  so  far  as  its 
glands  are  concerned,  have  already  been  specified  (p.  487). 

The  arteries  of  the  penis  need  description  here  only  in  regard  to 
the  manner  in  which  they  supply  the  corpora  cavernosa.  Very  small 
branches  run  in  a  convoluted  manner,  except  at  the  time  of  erection, 
in  the  axis  of  the  trabeculae,  ramify  in  them,  and  ultimately  open 
into  the  venous  spaces  by  ramuscules  o^^g^  to  yj'o^j  of  an  inch  in 

diameter.  (Fig.  381,  c.)  In  the  posterior 
part  of  the  penis  there  are  numerous 
minute  arterial  trunks  (gfij  to  yi^  of  an 
inch),  lying  from  3  to  10  together,  and 
being  convoluted  in  a  peculiar  tendril- 
like manner  (ai^terice  helicinaj);  though 
not  terminating  in  csecal  ends,  in  most 
instances  certainly,  as  they  were  sup- 
posed to  do  by  J.  Muller.  (Fig.  381.) 
The  arterial  ramification  is  precisely 
similar  in  the  corpiLs  spongiosum  urethrce. 
The  veins  commence  in  the  venous  spa- 
ces, which  intercommunicate  through- 
out; from  which  short  efferent  veins 
carry  the  blood  to  the  superficial  ones. 
The  hjmp>hatics  form  very  close  plexuses  in  the  corium  of  the  glans, 
and  the  prepuce,  and  the  remainder  of  the  integument,  and  commu- 
nicate with  the  superficial  inguinal  glands.     There  are  also  lymph- 


Fig.  381. 


Small  artery  of  the  corpus  caverno- 
Rum,  giving  off  a  lateral  branch  divid- 
ing into  hflicino  arteries  ;  terminating 
in  very  small  vessels,  which  are  con- 
tinued into  the  trabecular  tissue,  a. 
Arlerial  slioath  of  tra))ecular  tissue. 
6.  Wall  of  the  arteries,  c.  Capillary 
arteries. 


PROSTATE   GLAND  —  VESICUL^   SEMINALE3.  553 

atics  in  the  (jkins  around  the  urethra,  and  running  backwards  on 
that  canal  to  tlio  ])elvic  glands. 

The  nerves  of  the  penis  from  the  internal  pudic,  go  to  the  skin  and 
the  mucous  membrane  of  tlie  urethra,  and,  in  VQvy  small  amount,  to 
the  corpora  cavernosa;  while  all  those  from  the  sympathetic  are 
destined  to  the  latter.  The  former  nerve-fibres  terminate  like  those 
of  the  skin  generally;  of  the  terminations  of  the  latter,  nothing  is 
know^n. 

There  is  an  expansion  of  the  corpus  spongiosum  of  the  urethra 
opposite  the  root  of  the  penis,  called  the  hulh  of  the  urethra ;  and 
behind  this  is  the  membranous  and  then  the  prostatic  portion  of 
the  urethra — the  last  being  encompassed  by  the  prostate  gland. 

The  prostate  consists  partly  (one-third  to  one-half)  of  glandular 
substance,  and  the  rest  mainly  of  smooth  muscular  fibres.  1.  The 
glandular  portion  consists  of  30  to  50  compound  racemose  glands, 
generally  conical  or  pyriform,  situated  principally  in  the  more  ex- 
ternal parts  of  the  organ.  The  numerous  excretory  ducts  penetrate 
between  the  longitudinal  and  transverse  fibres,  and  open  into  tbe 
urethra  on  both  sides  of  the  cajnit  gallinaginis^  which  also  consists 
in  part  of  smooth  muscular  fibres.  The  caeca  of  the  prostate  gland 
are  lined  by  a  simple  scaly  epithelium;  their  ducts  by  a  conoidal 
one.  2.  The  muscular  portion  of  tbe  prostate  consists — Is/,  of  an 
external  layer  of  circular  fibres  continuous  with  the  sphincter  ve- 
sicas, extending  as  far  as  the  caput  gallinaginis ;  2dhj,  of  a  layer 
between  this  and  the  urethra,  composed  about  equally  of  areolar 
tissue  and  smooth  muscular  fibres,  extending  from  the  vesical  tri- 
angle to  the  caput  gallinaginis.  The  fibrous  coat  which  invests  the 
prostate  also  abounds  in  fasciculi  of  smooth  muscular  fibres. — The 
secretion  of  the  prostate  resembles  that  of  the  vesiculce  seminales, 
next  to  be  described. 

2  and  3.  The  vesiculce  seminaks  (Fig.  382),  with  the  ejaculatory 
ducts,  and  the  vasa  deferentia,  have  essentially  the  same  structure; 
consisting  of  an  external  fibrous  tunic,  then  a  layer  of  smooth  mus- 
cular fibres,  and  internally  a  mucous  membrane.  The  walls  of  the 
vesiculse  seminales  are  much  thinner  than  those  of  the  vasa  defe- 
rentia; the  latter  being  ^\  to  ^\  of  an  inch  thick,  while  their  whole 
diameter  is  j^.  ^o  g  of  an  inch,  and  their  cavity,  or  lumen,  ~g  to  -g^g  of 
an  inch.  The  ejaculatory  ducts  commence  from  the  prostatic  portion 
of  the  urethra  on  each  side  of  the  caput  gallinaginis,  and  become 
continuous  on  the  one  hand  with  the  vesicular  seminales,  and  on  the 


554 


THE   TISSUES. 


-^33> 


other  with  the  vasa  deferentia.  Since  the 
vesiculse  seminales  are  mere  appendages  of 
the  vasa  deferentia,  furnished  with  saccular 
or  branched  processes  (Fig.  382),  their  mu- 
cous membrane  is  also  similar ;  and  the  last 
remark  may  be  applied  also  to  the  ejacu- 
latory  ducts. — The  fluid  secreted  by  the  ve- 
sicula3  seminales  is  clear,  rather  viscid,  and 
contains  an  albuminous  compound  identical 
with  that  contained  in  •  the  ejaculated  semen. 
Since  spermatozoids  are  so  generally  con- 
tained in  it,  we  must  assign  to  these  append- 
ages the  double  of&ce  of  secreting  a  peculiar 
secretion,  and  of  being  a  receptacle  for  the 
semen. 

The  vasa  deferentia  have  a  muscular  coat 
aV  tf^  2^  of  an  inch  thick,  consisting  of  an 
external  layer  of  longitudinal  fibres,  a  middle 
one  of  transverse  and  oblique  fibres,  and  an 
internal  one,  constituting  not  more  than  one- 
fourth  of  the  whole  thickness,  of  longitudinal 
fibres.  The  mucous  membrane  is  ^l^  of  an  inch  thick,  yellowish 
white,  longitudinally  plicated,  and  in  the  widest  portions  of  the 
canal  presents  numerous  larger  and  smaller  fossas,  disposed  in  a 
reticular  manner.  The  deeper  two-thirds  of  the  coriufn  is  a  very 
closely  filled  structure  of  elastic  fibres,  while  the  remainder  is  more 
transparent.  The  epithelium  is  of  the  simple  scaly  variety,  the 
cells  almost  invariably  containing  some  brownish  pigment-granules. 
The  vessels  and  nerves  of  these  three  portions  of  the  genital  pass- 
ages require  no  particular  description. 

4.  The  testes  are  glands  inclosed  in  a  fibrous  tunic  (the  tunica 
albuginea),  which  also  sends  processes  into  the  interior  from  a 
thicker  portion  called  the  corpus  Highmorianum.  (Fig.  177.)  But 
for  the  particulars  respecting  this  and  the  other  tunics,  as  well  as  the 
vessels  and  nerves,  we  refer  to  the  works  on  descriptive  anatomy. 

The  glandular  substance  of  the  testes  consists  of  100  to  250  pyri- 
form  lobules — not  everywhere  separated,  however — the  apices  all 
converging  towards  the  corpus  Highmorianum.  Each  of  these 
lobules  is  formed  of  from  one  to  three  seminal  tubes  g'g  to  ygg  of 
an  inch  in  diameter;  which,  much  convoluted,  frequently  dividing, 


L'; 


Vesieula  seminalis.  a.  Eja- 
culatory  duct.  h.  Yas  deferens, 
c.  Vesieula  seminalis.  d.  Ter- 
minal diverticula.  {E.  H.  We- 
ber.) 


STRUCTURE   OF   THE   TESTIS. 


555 


and  perhaps  also  anastomosing,  form  a  compact  substance,  and  ter- 
minate at  tlie  base  of  the  lobule,  either  in  ciecal  extremities  or  in 

Fig.  383. 

e 


^ 


h's^^ 


structure  of  the  testis  and  epididymis,  a,  a.  Seminiferous  tubes,  a*,  a*.  Their  anastomoses. 
a.  Lobules  formed  of  the  seminiferous  tubes,  b.  Rete  testis,  e.  Vasa  efferentia.  d.  Flexures  of  the 
efferent  vessels  (cones)  passing  into  the  head  (e,  e)  of  the  epididymis.  /.  Body  of  the  epididymis. 
ff.  Appendix  (vasculum  aberrans).     h.  Tail  of  epididymis,     i.  Vas  deferens. 

loops.     (Fig.  383.)     Their  origin  in  c^ecal  extremities  is  shown  by 
Fig.  384.     Though  joined  together  by  some  areolar  tissue  and  ves- 

Ficc.  384. 


i^ri 


■p^l 


a.  Blind  extremities  and  branches  of  human  seminal  tubes,     b.  One  of  the  ca;ca  more  highly 

magnified. 

sels,  the  tubes  in  each  lobule  may  be  separated,  and  their  length, 
according  to  Lauth,  is  from  13  to  33  inches.  Estimating  the  ave- 
rage number  of  lobules  in  each  testis  at  175,  it  would  contain  from 


556 


THE   TISSUES. 


Fig.  385. 


189 1  to  481  feet  of  tubing.  Out  at  the  apex  of  each  lobule  a  single 
tube,  y^^  of  an  inch  in  diameter  (tubuli  recti),  passes  into  the  base 
of  the  corpus  Highmorianum.  These  form  a  very  close  plexus  (the 
rete  testis),  from  the  upper  end  of  which  proceed  7  to  15  efferent 
canals  (vasa  efferentia  testis),  gV  to  -^^  of  a  line  in  diameter,  which 
traverse  the  tunica  albuginea,  and  are  continued  into  the  epididy- 
mis. Here,  contracting  to  ^'g  to  ,1^  of  an  inch,  they  are  convoluted 
in  precisely  the  same  way  as  in  the  lobules, 
but  without  dividing  or  anastomosing ;  and 
thus  form  the  spermatic  cones.  These,  united  by 
connective  tissue,  constitute  the  head  (globus 
major)  of  the  epididymis;  at  the  upper  and 
posterior  border  of  which  their  canals  gradu- 
ally coalesce,  and  thus  a  simple  duct  is  formed, 
7^5  to  g'g  of  an  inch  in  diameter.  (Fig.  385.) 
This  duct  is  so  convoluted  as  to  form  the 
body  and  tail  (globus  minor)  of  the  epididy- 
mis; and,  after  giving  off,  usually,  a  ceecal 
prolongation  at  its  inferior  extremity  (vas 
aberrans),  is  ultimately  continuous  with  the 
vas  deferens,  already  described. 

Structure  of  the  Seminiferous  Tubes. 
The  tubuli  testis  consist  of  an  external 
fibrous  coat,  a  basement-membrane,  and  an 
epithelium,  these  together  being  y^^gu  to  72^011 
of  an  inch  thick.  The  first  averages  4^V^  to 
■3(jV(^  of  an  inch  in  thickness,  is  tolerably  firm 
and  extensible,  contains  no  smooth  muscular 
fibres,  and  rarely  any  indications  of  elastic 
tissue.  The  epithelium  is  simple  conoidal, 
approaching  to  the  scaly  variety.  In  young 
subjects  the  cells  are  pale  and  finely  granular; 
but  as  age  increases,  a  continually  increasing  quantity  of  fatty 
granules  is  collected  in  them,  giving  the  seminal  tubes  a  light  yel- 
lowish, partially  brownish  color.  The  tubes  in  the  rete  testis,  how- 
ever, appear  to  be  mere  passages  in  the  dense  tissue  of  the  corpus 
Highmorianum,  lined  by  an  epithelium.  But  in  the  cones  the  fibrous 
coat  again  appears,  and  to  it  is  added  a  coat  of  smooth  muscular 
fibres,  continuous  upon  the  vasa  defcrentia,  as  before  described. 


A  view  of  the  minute  struc- 
ture of  the  testis.  1,  1.  Tu- 
nica albuginea.  2,  2.  Corpus 
Highmorianum.  3, 3.  Tubuli 
seminiferi  convoluted  into  lo- 
bules. 4.  Vasa  recta.  5.  Rete 
testis.  6.  Vasa  efferentia.  7. 
Coni  vasculosi  constituting 
the  globus  major  of  the  epi- 
didymis. 8.  Body  of  the 
epididymis.  9.  Its  globus 
minor.  10.  Vas  deferens.  11. 
Vasculum  aberrans,  or  blind 
duct. 


STRUCTURE   OF   THE   SEMINIFEROUS   TUBES. 


657 


The  contents  of  the  seminal  tubes  vary  according  to  age.  Pre- 
viously to  puberty,  they  contain  nothing  but  minute  clear  cells, 
resembling  epithelial  cells.  At  this  period,  however,  the  tubes 
increase  in  size,  and  when  the  formation  of  semen  has  commenced, 
they  become  clear,  round  cells  and  cysts,  24^00  to  4^5  of  an  inch  in 
diameter,  inclosing  from  1  to  10,  or  even  20,  clear  nucleolated. 
nuclei,  ^(j'ou  ^^  ssVc  ^^  ^'''  i'l*^^^  ^^  diameter.  At  this  time,  also, 
the  epithelium  is  not  manifest,  the  cells  in  question  appearing  en- 
tirely to  fill  the  tubes  (Fig.  386);  though  at  other  times,  especially 

Fig.  386. 


Seminal  tube  (man),  with  contained  cells,  a.  Wall  of  tube.  h.  Nuclei  of  fibrous  coat.  c.  Base- 
ment-membrane, d.  Cells  removed  from  the  tube.  The  latter  figure  shows  the  action  of  acetic  acid. 
(Magnified  220  diameters.) 

in  advanced  years,  the  epithelium  appears,  containing  fat,  or  pig- 
ment-cells, surrounding  the  other  elements.  The  cells  and  cysts 
(spermatophori)  just  mentioned  are  the  precursors  of  the  semen; 
for  in  each  nucleus  a  spermatic  filament  (spermatozoid)  is  developed 
on  the  inner  wall,  as  a  spiral  corpuscle  with  two  or  three  turns. 
(Figs.  387  and  117.)  This  development  commences  in  the  tubuli  testis, 
but  it  is  not  completed  so  that  the  spermatozoids  become  liberated, 
till  they  reach  the  rete  testis  and  the  coni  vasculosi.  The  nuclei 
first  bursting,  the  spermatozoids  remain  for  a  time  in  the  cysts  or 
spermatophori,  the  heads  and  tails  together  when  numerous  (10  to 
20);  but  subsequently  the  spermatophori  also  burst,  in  the  epididy- 
mis, and  the  dense  entangled  crowd  thus  liberated  entirely  fill  its 


558 


THE   TISSUES. 


Development  of  spermato- 
zoids  in  the  spermatopbori  of 
the  rabbit,  a.  Parent  cellTV-ith 
five  nuclei,  b.  Each  nucleus 
containing  a  spermatic  fila- 
ment (spermatozoid).  c.  Nu- 
cleus with  spermatozoid.  d. 
A  parent  cell  with  several 
spermatozoids  set  free  from 
the  nuclei,  or  cells  of  develop- 
ment, and  coiled  together  in  a 
bundle. 


Fig.  SS7.  tubes,  some  of  tliem  still  being  collected  in 

bundles.  The  process  of  development  is 
usually  concluded  in  the  lower  part  of  the 
epididymis,  thougb  transitional  forms  are 
sometimes  found  in  the  vas  deferens. 

The  pure  semen,  as  found  in  the  vas  defe- 
rens, consists  of  a  very  small  quantity  of  a 
viscid  fluid,  together  with  the  spermatozoids 
just  spoken  of;  and  for  a  description  of 
whicli  we  refer  to  page  207,  and  Fig.  116. 
Semen,  as  emitted,  contains  the  secretions  of 
the  vesiculge  seminales,  and  of  Cowper's  and 
the  prostate  gland,  in  addition  to  the  two 
elements  before  mentioned.  The  movements 
of  the  spermatozoids  are  not  exhibited,  or 
slightly  if  at  all,  in  the  pure  semen  of  the 
vasa  deferentia ;  but  are  first  seen  in  the  less 
concentrated  contents  of  the  vesicular  seminales. — In  the  semen  of 
patients  who  have  suffered  attacks  of  double  epididymitis,  the 
spermatozoids  have  remained  absent  for  months,  and  even  years. 
{Gosselin.)  In  those  broken  down  by  seminal  losses,  they  are  im- 
perfectly developed,  the  tails  being  rough,  irregular,  and  indistinct. 
[Lallemand)  Henle  states  that  the  spermatozoids  move  at  the  rate 
of  1  inch  in  7|  minutes. 

The  ejaculation  of  the  semen  is  principally  secured  by  the  strong 
muscular  layer  of  the  vasa  deferentia,  their  action  being  also  con- 
tinued by  the  vesiculee  seminales,  the  very  muscular  prostate,  and 
the  layers  of  smooth  muscle  inclosing  the  urethra;  to  which  must 
also  be  added  the  action  of  the  striated  muscles,  levator  ani,  accele- 
rator urinae,  &c.  The  erection  of  the  penis  is  caused,  Ktilliker  main- 
tains, by  the  relaxation  of  the  smooth  muscular  fibres  contained  in 
the  trabeculae  of  that  organ,  and  the  consequent  flaccid  state  of  the 
venous  sinuses  and  their  distension  with  blood.  This  is  not,  how- 
ever, a  satisfactory  explanation.  The  distension  of  the  sinuses  of 
the  corpora  cavernosa  and  tte  corpus  spongiosum  with  blood  is, 
apparently,  the  immediate  cause  of  erection;  this,  doubtle.ss,  over- 
coming the  contractile  force  of  the  smooth  muscular  fibres  in  the 
walls  of  the  trabecule  for  the  time  being. 


SEXUAL  ORGANS  OF  THE  FEMALE.  559 

II.  Sbxual  Organs  of  the  Female. 

The  sexual  organs  of  the  female  are:  1,  the  vulva  ;  2,  the  vaghia; 
3,  the  uterus  and  oviducts;  and  4,  the  ovaries.  To  these  the  lacteal 
glands  must  also  be  added. 

1.  Of  the  external  genital  organs  of  the  female,  together  consti- 
tuting the  vulva,  the  clitoris  with  its  two  corpora  cavernosa  and 
glans,  presents,  on  a  small  scale,  precisely  the  same  conditions  as  the 
corresponding  parts  and  corpora  cavernosa  of  the  male;  the  mus- 
cular elements  being  even  more  readily  isolated. 

The  mucous  membrane  of  the  vulva  has  a  submucous  layer  of  a 
spongy,  highly  vascular,  areolar  tissue ;  and  a  compound  scaly  epi- 
thelium, 3  J^  to  y-J^  of  an  inch  thick.  Its  corium  -^^  to  g'^  of  an 
inch  thick,  is  everywhere  furnished  with  much  developed  papillae, 
T2  0-  to  ^\^  of  an  inch  long  on  the  labia  minora,  and  ^^g  to  -jig  of 
an  inch  on  the  clitoris.  It  also  contains  sebaceous  glands  on  the 
labia  majora  (of  -l^  to  -^^  of  an  inch),  in  connection  with  hair-sacs; 
and  still  more  abundantly,  and  mostly  without  the  latter,  on  the 
labia  minora,  j^o  to  ^^  of  an  inch  in  diameter;  and  sometimes  also 
round  the  orifice  of  the  urethra,  and  laterally  at  the  entrance  of  the 
vagina.  Common  racemose  mucous  glands  -^q  to  ^  of  an  inch  in 
diameter,  with  excretory  ducts  either  short,  or  even  J  an  inch  long, 
exist  around  the  orifice  of  the  urethra,  in  the  vestibule  and  the 
lateral  portions  of  the  entrance  of  the  vagina.  The  two  glands  of 
Bartholini  {Duverney' s)^  corresponding  to  Cowper's  glands  in  the 
male,  and  situated  at  the  inferior  extremity  of  the  hulhi  vestibuli^  are 
common  racemose  mucous  glands  J  an  inch  in  diameter,  with  pyri- 
form  ca3ca  lined  with  a  scaly  epithelium.  Their  ducts  are  7  to  8 
lines  long,  and  J  a  line  wide,  having  a  longitudinal  layer  of  smooth 
muscular  fibres  external  to  their  mucous  membrane,  and  a  conoidal 
epithelium  y^'o  o  ^^  ^^  mch.  thick.  The  labia  majora  contain  com- 
mon adipose  tissue  in  their  interior. 

2.  The  walls  of  the  vagina^  -^.j  of  an  inch  thick,  consist  of  an 
external  fibrous  coat,  a  middle  muscular  layer,  and  a  mucous  mem- 
brane. 1.  The  external  tunic  is  a  layer  of  areolar  tissue,  contain- 
ing plexuses  of  veins,  and  passing  without  any  line  of  demarcation 
into  the  middle  redder  layer,  consisting  of  areolar  tissue,  numerous 
veins,  and  some  muscular  fibres.  2.  The  latter  increase  durinor 
pregnancy,  and  becoming  3 -Jo  to  yi^  of  ^^  inch  long,  constitute  a 
true  muscular  membrane.     3.  The  raucous  membrane  is  pale  red, 


560  THE   TISSUES. 

presents  numerous  folds  and  elevations  (columnas),  and  has  a  com- 
pound scaly  epithelium  y^y  to  y|^  of  an  inch  tlfick,  like  that  of  the 
oesophagus;  its  scales  being  the  largest  in  the  body.  Its  corium  is 
■very  firm,  and  yet  very  extensible,  and  presents  numerous  conical 
or  filiform  papilla?  (Fig.  389,  c),  j^o  to  ^^^  of  an  inch  in  length, 
S'li^i  5^0  to  4^0  of  an  inch  broad,  which  are  entirely  imbedded  in 
the  epithelium.  They  are  very  numerous  at  the  lower  part  of  the 
canal,  but  diminish  towards  the  os  uteri.  It  has  no  glands  at  all, 
except  those  at  the  entrance,  already  described  (W.  Tyler  Smith'). 
The  hi/men  is  merely  a  duplicature  of  the  mucous  membrane  of  the 
vagina,  and  contains  the  same  elements. 

The  bloodvessels  of  the  vagina  and  vulva  present  no  striking  pe- 
culiarities. The  lymphatics  of  both  are  numerous,  and  communi- 
cate partly  with  the  inguinal  glands,  and  partly  with  the  pelvic 
plexus.  The  nerves  derived  from  the  sympathetic  and  the  pudendal 
branches,  are  extremely  numerous,  especially  in  the  clitoris ;  and 
are  also  easily  found  in  the  mucous  membrane  of  the  vagina,  pre- 
senting divisions  also  in  both.  Kcilliker  thinks  he  has  also  seen 
loops  in  the  rudimentary  axile  corpuscles  of  minute  non-vascular 
papillas  on  the  clitoris. 

3.  The  uterus  and  oviducts  (Fallopian  tubes)  consist  of,  1,  the 
peritoneal  coat,  which  presents  nothing  peculiar;  2,  the  muscular 
coat;  and  8,  the  mucous  membrane. 

The  muscular  coat  of  the  uterus  is  pale  red,  and  consists  of  three 
layers.  1.  The  external,  is  composed  of  longitudinal  and  transverse 
fibres,  the  former  intimately  united  to  the  peritoneum,  extending 
over  the  fundus  and  the  anterior  and  posterior  surfaces  of  the  cer- 
vix ;  while  the  transverse  fibres  surround  the  organ,  and  to  some 
extent  are  continued  into  the  round  ligaments,  and  upon  the  Fallo- 
pian tubes.  2.  The  middle  layer  is  the  strongest,  presenting  longi- 
tudinal, transverse,  and  oblique  flat  fibres,  and  containing  larger 
vessels,  chiefly  veins;  whence,  especially  in  the  pregnant  uterus,  it 
presents  a  spongy  appearance.  3.  The  inner  layer  is  also  formed 
of  slender  longitudinal,  and  stronger  transverse  and  oblique  fibres, 
forming  distinct  rings  at  the  commencement  of  the  Fallopian  tubes. 
In  the  OS  uteri,  highly  developed  transverse  fibres  lie  immediately 
under  the  mucous  membrane  constituting  an  occlusor  of  it  (sjihinc- 
ter  uteri).     All  these  layers  are  pervaded  by  a  great  quantity  of 

'  Oil  tlio  Tathology  and  Tieatineiit  of  Li.'11coit1iu.\i,  i)p.  20 — 29. 


STEUCTUEE   OF   THE   UTEEUS. 


561 


nucleated  embryonic  collagenous  tissue.  In  the  Fallopian  tubes,  the 
muscular  coat  is  thicker  in  the  inner  half,  and  consists  of  external 
longitudinal,  and  internal  transverse  fibres,  also  mixed  with  unde- 
veloped collagenous  tissue. 

The  mucous  memhrane  of  the  uterus  is  "whitish-red,  -|  to  1  line 
thick,  and  cannot  be  raised  from  the  muscular  coat,  it  is  so  closely 
connected  with  it.  Indeed,  since  the  corium  so  called,  also  con- 
tains smooth  muscular  fibres,  and  collagenous  tissue  without  any 
elastic  fibres,  it  has  no  clear  line  of  demarcation  from  the  muscular 
layer  underneath.  The  epithelium,  everywhere  except  in  the  canal 
of  the  cervix,  and  the  lower  third  of  the  uterine  cavity,  is  the  com- 
pound conoidal  ciliated  variety;  the  cells  being  i^\q  of  an  inch  in 
length,  and  the  cilia  vibrating  from  without  to  within.  In  the 
cavity  of  the  uterus,  the  corium  presents  no  papilla,  but  occasion- 
ally a  few  large  folds.  It,  however,  contains  numerous  minute 
glands  (glandul^e  uteringe),  bearing  a  striking  resemblance  to  the 
Lieberkuhnian  glands  of  the  intestines.  They  extend  through  the 
mucous  membrane,  being  g^^  to  ^^q  of  an  inch  in  diameter,  and 
thickly  placed.  They  are  simple  or  bifurcated,  as  shown  in  Fig. 
388.  Their  orifices  are  even  3  Jo-  of  ^^^  inoh  in.  diameter;  and  they 
are  lined  by  a  simple  conoidal  and  not  ciliated  epithelium. 


Fig.  388. 


Section  of  the  lining  membrane  of  a  liuman  uterus  at  the  period  of  commencing  pregnancy,  show- 
ing the  arrangement  and  other  peculiarities  of  the  glands  (d,  d,  d,)  -with  their  orifices  (a,  a,  a,)  on 
the  internal  surface  of  the  organ.     Twice  the  natural  size.     {Mlev  E.  M.  Weber.) 

The  mucous  membrane  of  the  canal  of  the  cervix  uteri  presents 
four  longitudinal  columns  of  rugas  or  folds,  the  latter  being  arranged 
in  an  oblique,  transverse,  or  curved  direction.  These  columns  are 
separated  by  four  longitudinal  grooves,  of  which  those  on  the  median 
line  anteriorly  and  posteriorly  are  the  most  distinct.  Sometimes 
the  grooves  are  replaced  by  ridges.  The  two  lateral  grooves  ex- 
tend through  the  canal  to  the  angles  dividing  the  anterior  and  pos- 
36 


562 


THE   TISSUES. 


terior  lips  of  the  os  uteri.     Thus  two  (larger)  columns  of  rugas 
correspond  to  the  posterior  lip,  and  two  (smaller)  to  the  anterior. 

Fig.  389. 


Papilla;  of  vagina  and  cervix  uteri,     a.  Of  the  vagina.     B.  Of  the  os  uteri,     c.  Of  the  canal  of  the 
cervix  uteri.    (W.T.Smith.) 

(Fig.  390.)     There  are  ten  to  fifteen  primary  lugse  visible  to  the 
naked  eye  in  each  column ;  between  which  many  secondary  rugas, 

Fig.  390. 


,,1111*"  „ll 

iW/""  "■"■'•:■ 


Kugie  of  cervix  uteri,    a.  The  cavity  of  a  virgin  cervix  uteri,  laid  open.    Natural  size.    b.  Side 
view  of  one  of  the  columns  of  rugie  and  fossje. — Magnified  60  diameters.    (]V.  T.  Smilh.) 

irregularly  arranged,  appear  under  the  microscope.  (Fig.  391.) 
Other  irregular  rugie  are  also  found  above,  below,  and  between  the 
columns  just  described.     All  tliese  fossa3,  thus  formed,  and  which 


STRUCTURE    OF   THE    UTERUS. 


i63 


Fig.  391. 


are  improperly  termed  follicles,  constitute  an  "open  gland"  {S'/nilh); 
and  which  secretes  the  clear 
viscid  mucus  of  the  cervix 
uteri.  Ilere  also  occur 
closed  vesicles  I-  to  even  2 
lines  in  diameter  (ovula 
ISTabothi),  composed  of  col- 
lagenous tissue  and  a  lining 
of  short  conoidal  cells,  and 
filled  with  a  whitish,  pearly 
coagulated  matter,  contain- 
ing glomeruli,  cytoid  cor- 
puscles, oil  drops,  and  some- 
times, also,  cholesterine. — 
They  are  generally  sup- 
posed to  be  merely  closed 
mucous  follicles;  but  since 
they  sometimes  occur  where 
no  follicles  exist,  they  must, 
in  some  cases  at  least,  be  a 
pathological  new  formation, 
as  cysts  very  often  are  in 
other  localities.  In  the 
lower  third  or  less,  of  the 
canal  of  the  cervix  uteri, 
^.  e.  below  the  rugie  just  de- 
scribed, are  verrucose  or 
filiform  papillae  xso  ^o  ^\ 
of  an  inch  long,  covered 
with  conoidal'  epithelial 
cells.  ( W.  Tyler  Smith,  Fig. 
389,  c).  Papillae  only  \  to 
^  as  large  as  these,  also 
abound  on  the  os  uteri  itself.     (Fig.  389,  B.) 

The  mucous  membrane  of  the  oviducts  (Fallopian  tubes)  is  thin, 
whitish-red,  soft,  connected  to  the  muscular  coat  by  a  small  quan- 
tity of  areolar  tissue;  and  presents  no  glands  nor  villi,  though  it 
has  a  few  longitudinal  folds.     From  the  uterus  to  the  free  border  of 


One  of  tho  four  longitudinal  columus  of  ruga;  from  the 
virgin  cervix. — Magnifiod  9  diameters.     (IF.  T.  Hinith.) 


'  Kolliker  states  that  these  cells  are  also  ciliated. 


564:  THE   TISSUES. 

the  fimbrioB  is  a  siugle  layer  of  conoidal  ciliated  cells,  joVo  to 
T2V0  of  an  inch  long,  whose  cilia  vibrate  towards  the  uterus — or  in 
a  direction  contrary  to  those  of  the  uterine  cavity  itself.  They 
may  aid  in  the  passage  of  the  ovum  into  the  latter;  but  cannot 
carry  the  semen  in  an  opposite  direction. 

The  round  ligaments  of  the  uterus  contain  longitudinal  bundles 
of  smooth  muscular  fibres,  surrounded  by  areolar  tissue ;  with  which 
are  associated  at  the  internal  abdominal  ring,  many  striated  muscu- 
lar fibres,  often  extending  nearly  to  the  uterus.  The  ligaments  of 
the  ovaries  also  contain  a  small  amount  of  smooth  muscular  fibres; 
and  between  the  two  folds  of  the  peritoneum  constituting  the  hi-oad 
ligaments  of  the  uterus,  a  small  amount  of  these  fibres  is  continued 
from  the  uterus. 

Except  that  the  veins  are  large  and  very  thin-walled  (uterine 
sinuses),  the  bloodvessels  of  the  unimpregnated  uterus  present  no- 
thing for  special  description.  The  lymphatics,  probably  commenc- 
ing in  the  mucous  membrane,  are  very  numerous,  and  proceed  in 
part  to  the  pelvic  and  partly  to  the  lumbar  glands.  The  nerves, 
from  the  hypogastric  plexus  and  the  pudendal  branches,  reach  the 
uterus  by  the  broad  ligaments,  and  ramify  from  the  body  to  the 
cervix,  being  most  altundant  in  the  latter.  Those  spread  out  upon 
the  surface  of  the  uterus  are  but  few  in  number.  {Dr.  Beclc.)  They 
are  not  in  the  uterus  furnished  with  any  ganglia  {Kblliker),  contrary 
to  the  assertion  of  Dr.  Lee,  of  London ;  and  their  condition  in  the 
mucous  membrane,  and  their  terminations  elsewhere,  are  unknown. 

Changes  in  the  Uterus  at  the  Menstrual  Period,  and  in  Pregnancy. 

At  the  menstrual  period  the  whole  uterus  enlarges  and  its  tex- 
ture expands;  principally,  doubtless,  from  the  distension  of  its  ves- 
sels. No  change  occurs,  apparently,  in  the  muscular  coat;  but  the 
mucous  membrane  becomes  thicker  (to  1  or  even  3  lines,  or  in  its 
projecting  folds  to  5  or  6  lines)  and  softer,  and  presents  easily  iso- 
lated uterine  glands,  1  to  3  lines  long,  and  gj 3  to  3^^  of  an  inch 
broad — and  many  immature  round  and  pyriform  cells.  The  blood- 
vessels throughout  the  uterus,  and  especially  of  the  fundus  and  the 
body,  are  much'  distended  with  blood.  This  is  especially  the  case 
with  the  superficial  capillary  plexus,  and  hence  the  bright  red  color 
of  the  mucous  membrane.  The  menstrual  Jluid  consists  of  blood 
poured  out  in  consequence  of  rupture  of  some  of  these  capillaries, 
with  cells  of  the  epithelium,  which  is  in  great  measure  thrown  ofl"; 


CHANGES   IN   THE   UTERUS   IN   PREGNANCY.  565 

but  which  is  again  rapidly  restored  after  the  catamenial  period  has 
passed  (p.  17(3,  e.) 

In  pregnancy^  changes  of  a  very  different  character  occur;  the 
increased  bulk  of  the  organ  being,  however,  the  subject  of  main 
interest  here.  The  principal  changes  occur  in  the  muscvJar  struc- 
ture of  tlie  uterus;  and  these  have  already  been  described  on  page 
388.  But  the  mucous  membrane  also  undergoes  manifold  changes; 
it  being  also  first  affected.  As  early  as  the  second  week  in  preg- 
nancy it  becomes  2  to  3  lines  thick,  is  softer,  redder,  has  more  pro- 
minent plicce,  and  is  more  distinct  from  the  muscular  coat.  The 
uterine  glands  become  2  to  3  lines  long ;  and  a  new  formation  of 
areolar  tissue  has  taken  place  in  the  corium.  These  peculiari- 
ties become  more  marked  as  time  advances;  and  the  greater  part 
of  the  hypertrophied  mucous  membrane  is  transformed  into  the 
decidtta  vera,  while  that  corresponding  to  the  attachment  of  the 
ovum  is  converted  into  the  placenta  uterina,  and  a  growth  from  the 
border  of  this  produces  the  rejiexa  around  the  ovum.  No  epithe- 
lium exists  on  the  decidua  after  the  first  month.  The  mucous  mem- 
brane of  the  cervix  takes  no  part  in  this  formation,  and  retains  its 
epithelium  (without  cilia),  during  the  whole  period  of  pregnancy. 

The  serous  coat  of  the  uterus  also  increases  in  thickness  during 
pregnancy,  but  less  than  the  mucous.  The  smooth  muscular  fibres 
also,  and  probably  the  striated,  increase  in  the  round  ligaments. 
The  bloodvessels  and  lymphatics  also  increase  in  length  and  calibre, 
and  the  nerves  appear  to  become  thickened  (though  it  is  doubtful 
whether  any  new  fibres  are  produced  in  them),  and  may  be  traced 
further  into  the  organ  than  at  other  times. 

The  return  of  the  uterus  after  parturition  to  a  state  similar  to, 
but  not  precisely  identical  with,  its  condition  previously  to  that 
state,  is  effected  (1,)  by  an  atrophy  of  the  muscular  structure,  so 
that  in  three  weeks  after  parturition  the  fibres  are  as  short  as  in  the 
virgin  uterus  (p.  389);  and  (2,)  by  the  complete  removal  after  par- 
turition of  the  placenta  and  decidua,  so  that  the  membrane  has  to 
be  formed  anew. 

4.  The  ovaries  consist  of  two  coats,  the  peritoneal  and  the  fibrous 
(tunica  albuginea),  and  the  stroma.  The  last  is  a  grayish-red, 
tolerably  firm  substance,  composed  of  embryonic  areolar  tissue, 
which  contains  the  ovisacs,  or  Graafian  follicles,  and  the  vessels. 
The  ovisacs  are  entirely  closed  round  cavities  ^  to  3  lines  in  dia- 
meter, and  imbedded  in  the  more  ])eripheral  parts  of  the  stroma. 


566  THE   TISSUES. 

There  are  from  30  to  100  in  each  ovary,  and  often  even  200;  while 
in  old  women  only  2  to  10,  or  even  none  at  all,  are  to  be  found. 

Each  mature  ovisac  consists  of  a  membrane  and  covtents.  The 
former  resembles  a  mucous  membrane,  consisting  of  (1,)  a  highly 
vascular  fibrous  layer  (tunica  fibrosa),  and  (2,)  an  epithelium.  Baer 
distinguished  the  outer  portion  of  the  fibrous  layer,  which  is  united 
to  the  stroma  by  a  loose  connective  tissue,  from  the  internal  thicker, 
softer,  and  reddish  portion.  The  epithelium  [memhrana  granulosa)^ 
lies  upon  a  basement-membrane,  is  tbVo^  to  toVo  ^^  ^^  moh  thick, 
lines  the  whole  sac,  and  on  the  side  of  it  towards  the  surface  of  the 
ovary,  presents  a  wart-like  thickening,  the  germinal  eminence  (cumu- 
lus proligerus).  This  is  ^^g  of  an  inch  broad,  and  envelops  the 
ovum  to  be  described  further  on.  (Fig.  392.) 
'^'     "'  Its  cells  are  polygonal,  with  large  nuclei  and 

frequently  yellowish  fatt}'-  granules  disposed 
in  several  layers.  (Fig.  145.)  The  contents  of 
the  ovisac  within  the  membrana  granulosa  are 
(1,)  a  clear  light  yellowish  fluid  of  the  density 
of  the  serum  of  the  blood  {liquor  foUicuU);  al- 
most always  containing  (2,)  isolated  granules, 
nuclei,  and  cells  detached  from  the  mem- 

Graafian   follicle  of   the  sow.    braua  grauulosa. 

a,    External,   b,  internal    layer  rp^  rCtUrn  tO  the  OVlim,   OT  egg.       This  licS 

of  the  fibrous  membrane  of  the  °" 

follicle,  c.  Membrana  granulosa,  closc  upou  the  fibrous  membrane  of  the  ovi- 

d.  Liq^rorfolliculi.    e.  Germinal  ^^  ^-^^  ^-^^  ^f  ^^^    ^^^^^^    looking  tO  the 

eminence,   a    projection   of   the  '  '^ 

lupmbrana granulosa.  /.  Ovum  surfacc  of  the  ovary,  and  imbedded  in  the 
with  a  zona  peiiucida,  viteiius,       ^j     ^^     germinal  eminence  before  de- 

and   germinal    vesicle. — Magni-    ^^'^'^^    ^'-    ""^    b 

fied  about  10  diameters.  (Kali-  scribcd.  Whcu  the  ovisac  bursts,  thc  ovum 
escapes,  completely  inclosed  by  the  cells  of 
the  eminence  and  the  contiguous  portion  of  the  epithelium,  consti- 
tuting the  germinal  disk  (discus  proligerus).  The  ovum  itself  is  a 
spherical  vesicle,  ^'g  to  xItj  of  an  inch  in  diameter,  possessing  the 
nature  and  constitution  of  a  simple  cell,  though  in  some  respects 
peculiar.  The  cell  wall  (vitelline  membrane),  is  a  simple  mem- 
brane, is  usually  5ijV-<i  to  24^5  of  an  inch  thick,  very  elastic  and 
firm,  and,  surrounding  the  contents  as  a  clear  transparent  ring,  is 
called  zona  peiiucida.  (Fig.  393.)  The  cell  is  completely  filled  by 
the  light-yellowish  yolk.  This  is  a  viscid  fluid  having  many  minute 
pale  granules  dispersed  in  it,  and  fatty  granules;  besides — in  thefully 


THE  OVUM — CORPORA  LUTEA. 


567 


Fig.  393. 


M 


formed  ovum — a  well-marked  vesicular  nucleus,  the  germinal  vesicle. 
This  is  g-J-ff  of  an  inch  in  diameter  with  clear  contents;  and  a  ho- 
mogeneous round  nucleolus  (of  -/^xJa-Q  of  an  inch)  on  its  surface — 
the  germinal  spot.     (Figs.  55  and  393.) 

The  arteries  of  the  ovary  enter  from 
its  inferior  border,  and  terminate  partly 
in  the  stroma,  and  partly  in  the  walls 
of  the  ovisacs,  where  is  an  inner  finer 
plexus  of  capillaries  extending  to  the 
basement-membrane  under  tbe  mem- 
brana  granulosa.  A  few  lymphatics 
come  out  from  the  hilus  ovarii^  and  pro- 
ceed to  the  lumbar  and  pelvic  glands. 
The  nerves  come  from  the  spermatic 
plexus,  and  enter  the  ovary  with  the 
arteries.  Their  ultimate  distribution  is 
not  yet  ascertained. 

The  ovisacs  are  constantly  becoming 
matured,  and  then  burst  as  above  men- 
tioned, from  the  commencement  of  pu- 
berty till  menstruation  ceases;  this  oc- 
curring principally,  but  not  exclusively, 
at  the  menstrual  period.  As  they  ap- 
proach the  time  of  bursting,  they  ac- 
quire a  diameter  of  4  to  6  lines,  and  at    „  .  ,     .      ,  ,,,      1, 

^  '  a,  IS  ruptured,  and  the  yolk  granules, 

length     project    beyond    the    surface    of     ^  and  the  germinal  vesicle  have  escaped 
,  ,^  .  ,1        .         •  11  through  the  opening.     (Coste.) 

the  ovary.     Meantime  the  tunica  albu- 

ginea  and  the  peritoneal  coat  become  thinner,  and  at  length  give  way; 
when  the  ovum,  being  situated  at  the  point  of  rupture  as  before  ex- 
plained, escapes,  surrounded  by  the  germinal  disk,  and  makes  its  wav 
into  the  uterus  through  the  Fallopian  tube.  The  empty  ovisac  is 
now  termed  a  corpus  luteum.  (Fig.  394.)  Occurring  in  the  ordinarv 
course  of  menstruation  they  are  termed /a  fee  corpora  lutea ;  and  true 
corpora  lutea,  if  in  connection  with  impregnation  of  an  ovum. 
Fig.  395  represents  three  corpora  lutea  of  pregnancy,  at  two  davs 
and  at  twelve  weeks  after  delivery  and  in  the  sixth  week  after 
conception ;  but  a  particular  description  of  them  is  out  of  place 
here.  The  yellow  plicated  appearance  in  the  interior  is  due  to  the 
thickened  condition  of  the  fibrous  membrane  of  the  ovisac;  and 


Mammalian  ova.  Upper  figure  an 
immature,  and  the  lower  a  mature 
ovum.  a.  Zona  pellucida.  b.  Yolk.  c. 
Germinal  vesicle,  d.  Germinal  spot. 
In  the  lower  figure,  the  zona  pellucida. 


568 


THE  TISSUES. 


the  contents  are  the  blood  poured  out  upon  the  rupture  of  the  ovi- 
sac, with  some  remains  of  its  original  liquid  contents.* 

Fig.  394. 


Human  ovary,    a.  Graafian  follicle  (ovisac)  with  opening.    6.  Inner  lining  of  follicle  (membrana 
granulosa),    c.  Outer  portion  of  the  same.    d.  Ovum.    e.  Vascular  •wall  of  ovisac.     {Coste.) 

Fig.  395. 


Corpora  Intea  of  different  periods,  b.  Corpus  luteum  of  about  the  sixth  week  after  impregnation, 
showing  its  plicated  form  at  that  period.  1.  Substance  of  the  ovary  ;  2,  substance  of  the  corpus 
luteum  ;  3,  a  grayish  coagulum  in  its  cavity.  (After  Dr.  Patterson.)  a.  Corpus  luteum  two  days 
after  delivery,    d.  In  the  twelfth  week  after  delivery.  (After  Dr.  Montgomery.) 

In  respect  to  the  fundioji  of  the  female  genital  organs,  it  may  be 
here  remarked  merely  that  the  Fallopian  tubes,  as  well  as  the  uterus 
and  the  vagina,  manifest  motor  phenomena.  The  application  of  the 
Fallopian  tubes  to  the  ovaries  to  receive  the  ovum  into  their  fim- 
briated extremity,  is  doubtless  secured  by  the  action  of  their  mus- 


'  For  the  most  satisfactory  account  of  tlie  corpus  luteum,  see  Prof.  J.  C.  Dalton's 
Prize  Essay,  Transactions  of  Amer.  Med.  Association,  vol.  iv. 


THE   LACTEAL   GLAND.  569 

cular  fibres.  The  muscular  structure  of  the  uterus  may  act  all  at 
once,  or  only  a  part  at  a  time;  as  during  parturition,  the  os  and 
cervix  are  at  first  at  rest,  while  the  fundus  and  body  are  contract- 
ing. In  convulsions,  the  whole  uterus  contracts  firmly  round  the 
child  {Kolliker) ;  in  retention  of  the  placenta,  the  contraction  is  con- 
fined to  the  fundus.  The  author  is  convinced  that  during  the  or- 
gasm a  descent  of  the  uterus,  an  opening  of  the  os,  and  a  dilatation 
of  the  canal  of  the  cervix  take  place. 

The  sensibility  of  the  interior  of  the  uterus  is  very  slight ;  care- 
ful sounding  of  its  cavity  usually  causing  no  pain,  and  intra-uterine 
instruments  being  worn  by  many  patients  in  the  treatment  of  ute- 
rine displacements,  with  very  little  inconvenience.  The  vagina 
also  has  but  little  sensibility  internally.  The  most  sensitive  parts 
of  the  vulva  are  the  clitoris,  and  the  entrance  to  the  vagina  at  the 
orifice  of  the  glands  of  Duverney. 

The  mucous  secretions  from  the  genital  passages  of  the  female 
have  already  been  specified  (p.  198).  For  the  changes  undergone 
by  the  impregnated  ovum  during  its  development  in  utero^  consult 
the  works  on  Embryology.  The  original  development  of  the  fe- 
male genital  organs — very  analogous  to  that  of  the  male  organs 
during  the  first  part  of  embryonic  life — will  also  be  omitted  here. 

5.  The  Lacteal  Glands. 
The  lacteal  glands  are  of  the  compound  racemose  variety,  cor- 
responding in  all  essential  particulars  with  the  parotid  and  the  pan- 
creas. Each  gland  consists  of  15  to  24  or  more  flattened  lobes  ^  to 
1  inch  wide,  and  which  are  composed  of  lobules  connected  by  areolar 
tissue,  containing  many  fat-cells.  The  terminal  casca  of  the  lobules 
are  rounded  or  pyriform,  and  ^fo  to  -^^-^  of  an  inch  in  diameter. 
(Figs.  398,  and  115.)  The  smallest  ducts  leading  from  these  have  a 
simple  scaly  epithelium ;  and  these  uniting,  form  the  larger  trunks. 
Each  of  the  latter  running  towards  the  nipple,  dilates  beneath  the 
areola  into  an  elongated  sac,  ^  to  J  of  an  inch  wide;^  then  con- 
tracting to  1  or  even  |  a  line,  it  bends  into  the  nipple,  and  finally 
opens  at  its  apex  in  a  separate  orifice,  -g'g  to  g^  of  an  inch  in  dia- 
meter, between  the  papillae  which  exist  there.  (Figs.  o06,  807,  308.) 
These  ducts,  about  20  in  number,  are  lined  by  a  so-called  mucous 
membrane,  longitudinally  plicated  in  the  largest,  and,  deep  in  the 

'  These  reservoirs  iu  the  cow  hokl  even  a  quart. 


570 


THE   TISSUES. 


gland,  containing  longitudinal  smootli  muscular  fibres.  {JTenle.) 
The  epithelium  is  conoidal  in  the  larger  ducts,  and  scaly  in  the 
smaller. 

Fig.  396. 


J 


Six  milk-fubes  of  the  lacteal  gland,  injected  from  the  nipple,  a.  The  straight  tubes  proceeding  to 
the  apex  of  the  nipple,  b.  Keservoirs,  or  dilatations  of  the  ducts,  c.  Branches  of  the  ducts,  d. 
Terminal  lobules.     {Sir  A.  Cooper.) 

Fig.  397.  The  nipple  and  areola  con- 

tain many  smooth  muscular 
fibres  (p.  477),  and  which  are 
much  increased  in  pregnanc3^ 
Its  compound  papillae  are  x^it 
to  -gjg  of  an  inch  long;  and 
their  direction  is  from  the  base 
towards  the  apex  of  the  nipple. 
The  cuticle  is  not  more  than 
5,^0  of  an  inch  thick;  while 
the  ]\Ialpighian  layer  is  ^l^  of 
an  inch  thick,  and  colored  in 
the  deeper  portion.  Over  the 
gland  itself,  the  papillae  are 
small  and  simple,  and  the  epi- 
thelium  still   finer.       In    the 

Terminallobuloof  lacteal  gland  with  ducts;  from  arCoIa,  hut  nOt  OU  the  nipple, 
a  puerperal  woman.-Magniflcd  70  diameters.    (Lan-     ^^^^^  ^^^  j^  SebaCCOUS  folH- 

ffer.)  ° 


THE    LACTEAL    GLAND. 


571 


clcs,  witli  fine  liairs  often  visible  on  tlie  exterior;  and  sudoriparous 
glands,  often  with  peculiar  contents. 

Fig.  398. 


Terminal  follicles  (cseca)  of  lacteal  gland  and  ducts  ;  from  a  woman  not  pregnant.  Numerous 
elastic  fibres  appear  on  the  wall  of  the  ducts,  and  the  cjeca  are  separated  from  each  other  hy  a  cont^i- 
derable  amount  of  areolar  tissue.     (Magnified  150  diameters.) 

The  bloodvessels  present  nothing  pe-  Fig-  399. 

cnliar,  except  the  venous  circle  in  the 
areola  (circulus  venosus  Halleri). — 
Lymphatics  abound  in  the  skin,  but 
are  not  found  in  the  gland.  The  same 
remark  also  applies  to  the  nerves;  ex- 
cept that  a  few  fine  twigs  are  found 
accompanying  the  vessels. 

The  secretion  of  the  lacteal  glands, 
the  milk.,  has  already  been  described 
(pp.  202-5).  In  their  development  the 
lacteal  follow  the  same  course  as  the 
cutaneous  glands,  being  at  first  merely 
a  solid  projection  of  the  stratum  Mal- 
pighii. 

The  structure  of  the  lacteal  gland  in  the  new-born  child  is  shown 
by  Fig.  399. 


^ 
O 


Lacteal  5,l<»nJ  of  a  nev\-born  chilJ. 
The  rudimentary  follicles  are  very  woll 
shown.     {Langer.) 


572  THE   TISSUES. 


CHAPTEE   XVI. 

THE   RESPIRATORY   ORGAN'S. 

The  respiratory  apparatus  consists  of  the  nasal  passages ;  tlie 
upper  part  of  the  pharynx ;  the  larynx;  the  trachea;  and  the  lungs. 
The  mucous  membrane  lining  all  these  constitutes  the  air-passages. 

1.  The  mucous  membrane  alone  of  the  nasal  passages^  needs  to 
be  described  here.  It  is  continuous  with  the  skin  of  the  nose  at 
the  entrance  of  the  nostrils,  and  with  the  mucous  membrane  of  the 
eye  through  the  lachrymal  passages.  It  is  intimately  connected 
with  the  periosteum  of  the  nasal  passages,  in  the  sinuses  and  some 
other  parts;  but  on  the  spongy  bones  and  the  septum,  forming  the 
direct  passages  to  the  pharynx,  it  is  thicker,  having  a  submucous 
layer  of  areolar  tissue  containing  plexuses  both  of  arteries  and 
veins.  The  corium  presents  papillee  resembling  those  of  the  skin, 
just  within  the  nostrils.  Its  epitlielium  is  of  the  compound  scaly 
variety,  like  that  of  the  skin,  to  the  distance  of  about  |  of  an  inah 
within  the  nostrils,  where  it  becomes  the  compound  conoidal  cili- 
ated epithelium,  there  being  two  layers  of  cells  (Fig.  400) ;  and 

Fig.  400. 


Section  of  the  ciliated  epithelium  of  the  nasal  passages,  a.  Superficial  cells  clothed  with  cilia. 
h.  Deeper  series  becoming  elongated  vertically,  c.  Various  shapes  of  the  perfect  ciliated  cells. 
(Magnified  180  diameters.) 

thus  continues'through  the  nasal  passages,  except  over  the  olfac- 
tory region  (p.  449).  The  same  epithelium  also  extends  over  the 
upper  portion  of  the  pharynx,  po.stcriorly  to  the  level  of  the  Larynx, 
and  in  front  over  the  posterior  surface  of  the  velum— this  portion 
constituting  a  part  of  the  air-passages,  as  already  stated  (p.  522). 


THE  RESPIRATORY  ORGANS  —  LARYNX  AND  TRACEEA.   573 

This  part  also  of  the  mucous  membrane  of  the  pharynx,  abounds  in 
glands.  1.  Kacemose  mucous  glands  ^'g  to  ^'^  of  an  inch  in  diameter, 
form  a  perfectly  continuous  layer  on  the  posterior  wall  around  the 
Eustachian  tubes,  and  on  the  posterior  surface  of  the  velum.  2.  Closed 
follicular  glands,  simple  as  well  as  compound,  are  met  with  on  the 
vault  of  the  pharynx,  where  the  mucous  membrane  is  closely  attached 
to  the  base  of  the  cranium.  A  glandular  mass  extending  from  one 
Eustachian  opening  to  the  other,  and  1  to  4  lines  thick,  is  constantly 
found  here.  This,  in  aged  persons,  frequently  presents  large  cavi- 
ties filled  with  puriform  masses.  Other  glands  also  exist  upon  the 
sides  of  the  pharynx,  and  on  the  posterior  surface  of  the  velum, 
which  probably  have  the  same  structure  as  the  mucous  sacs  on  the 
base  of  the  tongue  (p.  520). 

2.  The  larynx  and  trachea^  with  the  continuations  of  the  latter 
into  the  lungs  (bronchial  subdivisions),  resemble  in  form  the  excre- 
tory ducts  of  the  compound  racemose  glands,  which  the  lungs  may, 
in  fact,  be  regarded  as  being.  The  larynx  has  a  framework  of  car- 
tilages with  their  connecting  ligaments;  the  thyroid,  cricoid,  and 
two  arytenoid  being  true  (hyaline)  cartilages.  The  epiglottis,  how- 
ever, and  the  cartilages  of  Santorini  and  Wrisberg,  are  reticular 
cartilages  (p.  314);  and  the  cartilago  triticea  is  common  fibro-carti- 
lage.  Of  the  ligaments^  the  middle  crico-thyroid,  and  the  inferior 
thyro-arytenoid  {chordce  vocales)  contain  a  preponderance  of  elastic 
fibres,  and  are  of- a  yellow  color.  The  other  ligaments  and  the 
hyo-thyroid  membrane,  also  contain  an  abundance  of  this  element. 
To  the  cartilages  and  ligaments  just  mentioned,  the  striated  muscles 
of  the  larynx  are  attached;  but  which  present  nothing  peculiar  to 
the  histologist. 

The  mucous  menibrane  of  the  larynx,  continuous  with  that  of  the 
mouth  and  pharynx,  is  smooth  and  whitish-red,  and  above  the 
chordas  vocales,  has  an  abundant  layer  of  areolar  tissue  under  it. 
The  membrane  is  very  closely  adherent  to  the  vocal  cords,  and 
where  it  lines  the  larynx  below  them ;  and  is  prolonged  into  its  ventri- 
cles. Its  coriwm  presents  no  papillae,  and  its  outer  portion  abounds 
in  elastic  networks.  The  epithelium  on  the  epiglottis  is  compound 
scaly,  like  that  of  the  oral  cavity.  At  its  base  and  above  the 
upper  vocal  ligaments,  commences  the  compound  conoidal  ciliated 
epithelium^  lining  the  air-passages  throughout.  It  is  here  com- 
posed of  several  layers  of  cells,  and  is  g  J^  to  3/,^  of  an  inch  thick. 
The  external  {ciliated)  cells  are  g^^  to  g^^  of  an  inch  long,  by  guVij 


574  THE   TISSUES. 

to  30V0  of  an  inch  broad,  on  tlie  average,  witli  elongated  round 
nuclei,  and  occasionally  a  few  fat-granules.  The  cilia  are  fine 
transparent  processes  of  the  cell-membrane,  goVo  to  3^0  of  an  inch 
long,  rising  in  a  broader  basis  and  terminating  in  a  pointed  extre- 
mity. They  have  been  described  on  page  243 ;  their  motion  some- 
times continuing  72  hours  after  death.  It  should  be,  however,  re- 
marked that  the  epithelium  on  the  vocal  cords  is  a  scahj^  and  not  a 
conoidal  ciliated  one ;  as  discovered  by  H.  Rheiner. 

The  mucous  membrane  of  the  larynx  also  contains  a  large  num- 
ber of  minute  racemose  glands  (^i^  to  ^'^  of  an  inch),  like  those  of 
the  mouth,  pharynx,  &c.,  with  C£eca  lined  by  a  scaly,  and  ducts  by 
a  conoidal,  epithelium.  They  occur  sparsely  on  the  posterior  sur- 
face of  the  epiglottis.  At  the  entrance  of  the  larynx  in  front  of 
the  arytenoid  cartilages,  they  form  a  large  mass,  a  horizontal  por- 
tion of  which  envelops  the  cartilage  of  Wrisberg,  while  another 
dips  down  into  the  laryngeal  cavity.  Glands  also  abound  in  the 
external  wall  of  the  ventricles  of  the  larynx,  behind  and  above  the 
sacciform  ligaments.     All  these  glands  secrete  pure  mucus. 

The  bloodvessels  of  the  larynx  are  numerous,  but  require  no  spe- 
cial description.  The  numerous  lymiiiliaiics  are  received  by  the 
deep  cervical  glands.  Of  the  nerves^  the  more  sensitive  superior 
laryngeal  contains  more  fine  fibres ;  while  the  inferior  laryngeal  has 
more  thick  fibres.  {Bidder^  Volchmann).  They  terminate  in  the 
muscles,  the  perichondrium,  and  especially  in  the  mucous  mem- 
brane. The  branches  going  to  the  ej)iglottis  are  furnished  with  mi- 
croscopic ganglia. 

3.  The  trachea  contains  a  series  of  rings  of  true  cartilage,  each 
completing  about  §  of  a  circle;  and  between  their  separated  extre- 
mities is  a  transverse  layer  of  smooth  muscular  fibres.  On  the 
outer  aspect  of  this,  are  isolated  longitudinal  muscular  fasciculi, 
rising  by  minute  tendons  of  elastic  tissue  partly  from  the  inner 
surface  of  the  ends  of  the  tracheal  rings,  and  partly  from  the  ex- 
ternal fibrous  membrane;  which  covers  the  cartilages  as  a  perichon- 
drium, and  at  the  same  time  the  muscular  layer,  and  connects  the 
different  cartilages  together. 

The  mucoiis  memhrane  of  the  trachea  has  a  layer  of  close  areolar 
tissue,  tJjj  of  an  inch  thick  beneath  it,  and  its  corium  consists  of 
two  layers:  1,  an  external,  of  areolar  tissue,  tJ^  of  an  inch  thick, 
and,  2,  an  internal,  yellow,  -^'g  to  -yio  of  an  inch  thick,  almost  en- 
tirely composed  of  longitudinal  elastic  fibres.     The  epillbelium  is 


RESPIRATORY  ORGANS — THE  LUNGS.        0(0 

ciliated  as  in  the  larynx,  and  difiers  in  no  respect  from  the  latter. 
The  glands  in  the  mucous  membrane  of  the  trachea  are  numerous; 
the  larger  occurring  more  in  the  posterior  wall,  externally  to  the 
muscles  and  the  whole  mucous  membrane,  while  the  smaller  are 
more  numerous  on  the  anterior  wall,  and  just  exterior  to  the  elastic 
layer  of  the  membrane.  The  larger  have  a  scaly  epithelium  in 
their  cscca;  while  the  smaller,  being  only  simple  or  bifurcated 
follicles  in  the  thickness  of  the  membrane  itself,  have  a  conoidal 
epithelium. 

The  bloodvessels  have  their  larger  branches  running  longitudi- 
nally, while  the  superficial  capillary  plexus  is  close  beneath  the 
basement-membrane. — The  lymphatics  are  abundant;  commencing 
(in  one  case)  in  wide  meshed  plexuses,  yaioo  to  ^o\o  of  an  inch 
broad,  of  thin-walled  vessels  giving  oft"  csecal  processes.  [Kolliker.) 

4.  The  lungs  are,  structurally,  to  be  regarded  as  two  compound 
racemose  glands;  and  an  accurate  knowledge  of  the  structure  of 
one  of  the  lobules,  therefore,  implies  that  of  a  whole  lung.  The 
lungs  are  invested,  however,  externally,  by  a  serous  membrane,  the 
pleura ;  which,  like  the  peritoneum,  forms  a  closed  cavity,  and  con- 
sists of  two  portions — the  pleura  costalis  lining  the  thoracic  cavity, 
and  the  pleura  ^Jw^TTzonaZis,  directly  adherent  to  the  lung.  In  struc- 
ture, also,  the  pleura  entirely  corresponds  with  the  peritoneum  (see 
p.  523);  the  parietal  layer  being  the  thicker  and  most  adherent, 
and  its  epithelium  being  the  simple  scaly  variety.  The  pulmonary 
layer  is,  however,  the  more  vascular. — Nerves,  with  fine  and  coarser 
fibres,  are  sent  to  the  parietal  layer,  from  the  phrenic  and  the  sym- 
pathetic {Luschka);  and  Kolliker  has  seen  medium  and  thick  nerve- 
fibres  accompanying  the  branches  of  the  bronchial  arteries  in  the 
pleura  costalis,  and  occasionally,  large- scattered  ganglion-cells  also. 

The  lung  proper  consists — 1st,  of  the  continuations  of  the  trachea 
(the  bronchi  and  their  subdivisions)  into  the  air-cells;  2(Z/?/,  the  ves- 
sels and  nerves ;  and,  2>dhj,  the  connective  tissue  binding  all  these 
elements  together  in  the  lobules. 

1.  The  bronchi  and  their  subdivisions  in  the  lung  have  the  same 
structural  elements  as  the  trachea,  on  a  diminished  scale;  except 
that  the  cartilaginous  rings  entirely  disappear  in  the  finer  subdi- 
visions (under  ^^  of  an  inch),  and  in  the  finest  the  fibrous  tunic 
coalesces  with  the  mucous.  The  smooth  om/scuhr  fibres  constitute 
a  completely  continuous  layer  in  the  smaller  subdivisions,  and  ter- 
minate I  of  an  inch  short  of  the  last  air-cells  to  which  thev  lead. 


576 


THE   TISSUES. 


Fig.  401. 


Small  bronchial  tube 
laid  open,  showing  the 
transverse  plexiform  ar- 
rangement of  the  mus- 
cular layer,  and  its  dis- 
position at  the  orifice  of 
a.  branch.  From  a  man 
aged  50.  (Magnified  2 
diameters.) 


Their  appearance  in  twigs  yj^  to  y^^  of  an  inch  in  diameter  is 
shown  by  Fig.  401.  Finally  the  bronchi  end  in  the  lobular  imssages. 
The  mucous  membrane  lining  the  bronchi  and 
their  subdivisions  is  at  first  like  that  of  the  tra- 
chea, but  gradually  becomes  extremely  thin  in 
tubes  of  less  than  ^^  of  an  inch.  It  everywhere 
consists  of  a  layer  of  elastic  fibres,  a  basement- 
membrane  6 oVo  to  4 oVo  of  ^"^  inch  thick,  and  a 
ciliated  epithelium.  The  last,  even  down  to  tubes 
1  line  in  diameter,  contains  several  layers  of  cells; 
but  is  finally  reduced  to  a  single  layer  of  conoidal 
ciliated  cells,  ooVo  of  an  inch  long.  In  the  larger 
branches,  racemose  mucous  glands  are  also  found, 
but  these  are  wanting  in  tubes  of  less  than  1  to 
1|  line  in  diameter.  The  subdivisions  of  the 
bronchial  tubes  do  not  anastomose.  The  air-cells 
will  be  described  in  speaking  more  particularly 
of  the  lobules. 
2.  The  iiulmonary  arteries  enter  the  substance  of  the  lung  in 
company  with  the  bronchi,  and  follow  their  subdivisions  also, 
though  more  frequently  dividing  dichotomously,  and  hence  more 
rapidly  diminishing  in  size.  Finally,  the  terminal  branches  occa- 
sionally, but  not  regularly,  anastomosing,  merge  exclusively  into 
the  capillary  plexus  of  the  air-cells  in  each  lobule — to  be  described 
further  on — except  a  few  fine  branches  to  the  pleura.  [Henle)  The 
pulmonary  veins  rise  from  this  plexus,  in  radicles  more  superficial 
than  the  arteries,  and  more  external  in  the  smallest  lobules;  and 
unite  to  form  larger  trunks,  proceeding,  in  gi'eat  part  isolated  from 
the  arteries,  through  the  pulmonary  substance. — The  hronddal  arte- 
ries are  distributed — Isi,  to  the  larger  bronchial  tubes ;  2dly^  to  the 
pulmonary  veins  and  arteries,  as  their  vasa  vasorum  (to  the  latter 
even  -^^  of  an  inch  in  diameter);  and,  ^dly^  to  the  pleura pidmonalis. 
They  do  not  go  to  the  mucous  membrane  at  all,  and  do  not  anasto- 
mose with  the  pulmonary  artery  or  vein. — The  lymphatics  are  nume- 
rous, but  require  no  distinct  description.  The  bronchial  lymphatic 
glands  are  both  numerous,  and  colored  dark  brown  or  black  by  a 
carbonaceous  deposit.  The  nerves,  from  the  pneumogastric  and  the 
sympathetic,  arc  furnished  in  the  interior  of  the  lung  with  micro- 
scopic ganglia,  and  may  be  traced  nearly  to  the  termination  of  the 


THE   RESPIKATORY   ORGANS  —  LUNGS. 


577 


broncliial  subdivisions.     They  accompany  the  pulmonary  artery, 
and  occasionally  the  veins  and  the  bronchial  arteries. 

3.  The  interlobular  connective  tissue  of  the  lungs,  everywhere 
existing  very  sparingly,  is  the  common  areolar,  containing  in  the 
adult  a  quantity  of  blackish  pigment  in  the  form  of  irregular  minute 
granules,  aggregations  of  granules,  or  crystals,  but  which  are  never 
inclosed  in  cells.  They  also  frequently  exist  in  the  walls  of  the 
air-cells  themselves  (p.  132). 

The  pulmonary  lohules  are  far  more  distinct  in  the  infant  and 
child  than  in  the  adult.  In  the  latter,  they  are  so  intimately  united 
that  even  on  the  surface  of  the  lung  their  outlines  are  but  imper- 
fectly perceived.  They  are  -^-g  to  ^\,  of  an  inch  in  diameter.  The 
secondary  lobules,  however — ^  to  1  inch 
in  diameter — are  very  apparent,  being 
bounded  by  streaks  of  pigmentary 
matter. 

Each  lobule  is  of  a  more  or  less 
conical  or  pyramidal  form,  and  consists 
of — A,  a  terminal  bronchial  tube ;  B, 
the  air-cells ;  and  c,  the  capillary  plex- 
us; besides  the  nerves  and  some  con- 
nective tissue. 

A.  The  terminal  air-tubes   are   from 


Fig.  402. 


Termination  of  the  bronchi  in  the 
lung  of  the  dog.  a.  Terminal  tube,  and 
its  branches  (lobular  passages),  and  the 
infundibula.  6.  One  of  the  last.  c.  Septa 
projecting  inwards  on  the  infundibular 
wall,  and  forming  the  alveoli  or  cells. 
(From  Rossignol.) 


1 


to 


1 
75 


(g'u  to  4^u  of  ^11  ii^ch — Todd 
and  Bowman)  of  an  inch  in  diameter. 
They  enter  at  the  apex  of  the  lobule, 
and,  passing  nearly  in  its  axis,  termi- 
nate in  the  lobular  passages  and  infun- 
dibula (the  former  being  ^^^  to  -xho  of 
an  inch  in  diameter),  as  shown  in  Fig. 
402.  The  air-cells  open  into  the  in- 
fundibula, and  their  appearance  in  the 
lobule,  as  seen  from  without,  is  shown 
by  Fig.  403. 

B.  The  air-cells  are  grouped  around 
and  open  directly  into  the  infundibula. 
A  few,  indeed,  open  thtis  into  the  air- 
tube  before  it  divides.  (Fig.  403.)  Thus 
a  honey-comb  appearance  is  afforded 
by  the  cells,  as  seen  in  their  relations 
37 


Fig.  403. 


Two  small  pulmonary  lobules  {a,  a), 
with  tlio  air-cells  (6,  6),  and  the  finest 
broncliial  twigs  (c,  c) ;  upon  which  air- 
cells  are  also  placed.  From  a  new-born 
child.  Half  diagrammatic. — Jlagoified 
25  diameters.  (KCllikei:) 


578 


THE   TISSUES. 


Fi?.  404. 


Thin  slice  from  the  pleural  surface  of  a  cat's  lung,  considerably  magnified.  At  the  thin  edge  (6,  e, 
d),  cells  (alveoli)  are  seen.  In  the  centre  (at  a),  where  the  slice  is  thicker,  cells  are  seen  on  the  walls 
of  infundibula,  and  opening  into  the  latter.     (From  Rossignol.) 

to  tlie  infundibula,  in  sections  of  the  latter.  (Fig.  404.)  There  are 
about  18,000  air-cells  in  communication  with  each  terminal  air- 
tube,  and  the  number  of  cells  in  both  lungs  is  estimated  at  600 
millions.  [Rochoux.)  The  size  of  the  cells  varies  considerably; 
they  being  after  death,  and  when  not  distended  with  air,  from  ^jg 

to  ^V  of  an  inch  in  diameter. 


Fig.  405. 


Walls  of  tho  air-cells,     a.   Epithelium,     b.   Elastic 
trabeculai.  c.  Membranous  walls  with  fine  elastic  fibres. 


They  may,  however,  be  dis- 
tended to  two  or  three  times 
this  diameter  without  rup- 
turing; and  are,  probably,  at 
least  one-third  larger  during 
life  than  after  death.  In  a 
collapsed  lung,  they  are  usu- 
ally of  a  rounded  oval  form; 
when  inflated,  they  are  round- 
ed angular;  and  those  on  the 
surface  of  the  lung  are  inva- 
riably polygonal,  and  their 
external  sides  almost  always 
plane. 

In  structure,  they  present 
merely  a  wall  (fibrous  mem- 
brane) and  an  epithelium. 
The  former  has  been  regard- 
ed as  the  attenuated  mucous 


THE   RESPIRATORY   ORGANS  —  AIR-CELLS, 


579 


membrane  and  fibrous  tunic  of  the  bronchial  tubes  {KoUilcer);  but 
it  is,  in  fact,  made  up  of  elastic  tissue  and  vessels,  in  a  homogeneous 
matrix.  The  elastic  fibres  present  the  form,  chiefly,  of  separate 
trabeculoe  and  filaments,  running  between  the  epithelial  linings  of 
the  air-cells,  and  supporting  the  capillary  vessels,  (Fig.  405.)  By 
anastomosing  with  each  other,  they  constitute  a  firm  frame,  on 
which  the  softer  vessels  are  stretched,  while  over  them  the  epithe- 
lium is  laid.  These  elastic  trabeculas  mutually  coalesce,  so  that,  for 
the  most  part,  the  boundaries  of  the  separate  air-cells  cannot  be 
recognized  where  the  latter  abut  upon  each  other. 

The  epithelium  of  the  air-cells  is  the  simple  scaly  variety,  com- 
posed of  pale,  polygonal,  granular  cells,  averaging  5^'oTJ  ^^  ^"^  inoh 
in  width,  and  3  g^^o  of  an  inch  in  thickness.  It  lies  immediately  on 
the  fibrous  walls  (just  described)  of  the  air-cells, 

C.  The  capillary  plexus  of  the  lobules  is  one  of  the  closest  in  the 
human  body,  presenting  rounded  or  oval  meshes  ^-q-q-q  to  y ^g^  of 


Fig.  406, 


Fig,  407. 


Fig.  406.   Arrangement  of  the  capillaries  of  the  air-cells  of  the  human  lung. 

Fig.  407.  Slightly  oblique  section  through  a  bronchial  tube.  a.  The  cavity  of  the  tube.  h.  Its 
lining  membrane,  containing  bloodvessels  with  large  areolte.  e,  c.  Perforations  in  this  membrane, 
where  it  ceases,  at  the  orifice  of  the  lobular  passages,  d,  d.  e,  e.  Spaces  between  contiguous  lobules, 
containing  the  terminal  pulmonary  arteries  and  veins  supplying  the  capillary  plexus  (/,/),  to  the 
meshes  of  which  the  air  gains  access  by  the  lobular  passages. 

an  inch  wide,  and  vessels  4  oVo  to  3  4*00  ^^  ^^^  ^^"^^  i^  diameter,^    It 
lies  in  the  wall  of  the  air-cells,  about  ysootj  of  ^^  inch  from  the 


'  Todd  and  Bowman  make  the  capillaries  so  large  (y sofi  of  an  iucli)  as  to  secure 
a  free  circulation,  and  intimate  that  the  blood  traversing  them  moves  IJ  inch  per 
minute.     Each  capillary  extends  over  8  to  10  air-cells,  and  the  air  remains  in  con- 

••act  with  the  blood  1^  second,   {Raiiiey.) 


580  THE   TISSUES. 

epithelium;  some  of  the  vessels  also  projecting  fairly  into  the  cells, 
since  they  are  sometimes  thicker  than  the  walls  of  the  latter.  It 
continues  not  only  over  all  the  air-cells  of  the  same  lobule,  but  also 
anastomoses  with  the  plexuses  of  the  contiguous  lobules.  A  great 
portion  of  the  capillaries  are  also  situated  between,  and  in  relation 
with,  two  air-cells  at  the  same  time.  Fig.  406  shows  the  capillary 
plexus  seen  on  the  walls  of,  and  between,  the  air-cells,  after  the 
epithelium  is  removed. — There  is  also  a  capillary  plexus  on  the 
surface  of  the  smallest  air-tubes,  and  even  extending  to  the  trachea, 
in  continuation  with  the  preceding,  characterized  by  the  elongated 
form  of  its  meshes  (ITeale^),  and  formed  of  vessels  almost  as  fine  as 
those  of  the  air-cells  (30V0  to  o^'^j^  of  an  inch),  (Fig.  407.)  Only 
the  pure  aerated  blood  enters  this  plexus,  since  it  has  previously 
circulated  through  the  capillaries  of  the  air-cells. 

Function  of  the  Respiratory  Apparatus. 

The  air-tubes  merely  conduct  the  air  to  and  from  the  air-cells  of 
the  lungs.  It  is  not  probable  that  the  epithelium  becomes  desqua- 
mated to  any  considerable  extent  in  disease.  At  least,  it  is  certain 
that  in  croup  an  exudation  may  occur  through  the  epithelium  with- 
out detaching  its  cells,  and  which  may  subsequently  be  coagulated 
into  a  "  false  membrane,"  falsely  so  called,  or  undergo  degeneration 
into  pus  (pp.  497  and  189). 

The  lungs  are  the  aerating  organs  of  the  blood ;  i.  e.  they  secrete 
carbonic  acid  gas  from  the  blood  in  the  capillary  plexus  in  the  walls 
of  the  air-cells,  and  absorb  oxygen  at  the  same  time  into  the  blood. 
The  layers  interposed  between  the  air  in  the  cells,  and  the  capillary 
vessels,  are  but  54^x7  of  an  inch  thick  on  an  average.  The  whole 
amount  of  surface  presented  to  the  air  by  the  six  hundred  million 
air-cells  in  the  lungs,  has  been  estimated  at  132  square  feet,  or  more 
than  eight  times  as  great  as  the  cutaneous  surface  of  the  body ;'  and 
all  the  blood  in  the  body  traverses  the  capillary  plexus  spread  out 
on  the  air-cells,  probably,  within  the  space  of  two  minutes. 

Development  of  the  Lungs. 
The  lungs  appear  a  little  after  the  liver,  as  two  hollow  protru- 
sions of  the  anterior  wall  of  the  pharynx ;  into  the  composition  of 
which  the  epithelium  and  the  corium  of  the  pharynx  equally  enter. 

'  American  Medical  Monthly,  vol.  ii.  p.  302. 

*  Lindenau  computed  the  whole  surface  of  the  air-cells  and  the  air-tubes  at 
2642  square  feet ! ! ! 


PATHOLOQICAL   STATES   OF   THE   LUNGS. 


i81 


A  continually  increasing  number  of  arborescent  hollow  processes 
spring  from  the  extremities  of  the  original  protrusions,  and  in  the 
6th  month  the  air-cells  are  developed  from  the  dilated  extremities. 
New  cells  are,  however,  continually  added,  up  to  birth,  but  not  sub- 
sequently. Before  they  are  filled  with  air  in  the  new-born  child, 
they  are  ^^^  of  an  inch,  and  after  breathing,  ^^^  to  ^hji  of  an  inch 
in  diameter.  The  subsequent  increase  of  the  lungs  consists  in  an 
expansion  of  all  their  parts. 

Pathological  States  of  the  Lungs. 

1.  In  emphysema,  the  air-cells  become  permanently  dilated  to  two 
or  three  times  their  normal  diameter;  or  become  even  ruptured,  so 
that  the  cells  of  the  same,  or  even  of  different  lobules,  become  con- 
fluent.    Their  wall  becomes  very  thin. 

The  bronchial  arteries  become  dilated  in  cases  where  the  circula- 
tion through  the  pulmonary  arteries  is  interrupted ;  the  former  re- 
placing branches  of  the  latter,  and  becoming  aerating  vessels. 

2.  Hypertrophy  o^  \he  air-cells  occurs  in  hypertrophy  of  the  lungs 
from  increased  functional  action. 

3.  The  air-cells  become  obliterated  by  exudation  or  deposit  (e.  g. 
tubercular),  in  the  cavities  or  their  walls,  or  into  the  interlobular 
areolar  tissue.  Bed  hepatization  is  produced  by  a  complete  filling 
of  the  air-cells  by  the  exudation  of  pneumonitis;  in  gray  hepatiza- 
tion the  walls  of  the  cells  and  the  interstitial  tissue  become  softened, 
and  undergo  a  fatty  metamorphosis.  [Kolliker.^) 


Fig.  408. 


Fig.  409. 


Fig.  40S.  Section  of  gray  granulations,  after,  addition  of  acetic  acid  ;  showing  the  air-cells  filled 
with  tubercle  nuclei. 
Fig.  -109.  Cretaceous  transformation  of  tubercle,  with  crystals  of  cholesterine. 


'  See  also  p.  193,  2. 


582  THE   TISSUES. 

Deposits  of  pigment  occur  as  a  consequence  of  hepatization,  or 
from  a  simple  congestion  of  the  lungs.  Tubercle  (gray  granula- 
tions) is  most  frequently  deposited  in  the  air-cells  (Fig.  408);  cancer, 
in  the  interstitial  tissue.  The  former  is  liable  to  cretaceous  trans- 
formation (Fig.  409). 

4.  In  oedema  of  the  lung,  serum  is  efPased  into  the  air-cells;  in 
a2)opIexi/,  blood  is  extravasated  into  the  interstitial  tissue. 

5.  The  epithelialcells  undergo  a  /((tty  degeneration  in  portions  of 
the  lung  encompassed  by  a  pleuritic  effusion,  in  atelectasis  {Rein- 
hardt),  and  in  splenization. 

6.  New  formations  (bone  and  cartilage),  and  C3'-sts,  are  generally 
noticed  in  the  interstitial  tissue. 

7.  The  parenchyma  of  the  lung  is  destroyed  by  inflammation, 
gangrene,  tubercle,  or  cancer;  the  elastic  fibres  usually  being  well 
preserved,  while  the  remaining  elements  are  infiltrated  with  fine 
fatty  molecules. 

For  the  pathological  states  of  the  air-passages,  reference  may  be 
made  to  the  works  on  pathological  anatomy. 


CHAPTER    XVII. 

THE   BLOOD-VASCULAR   GLANDS. 

This  class  includes  a  series  of  organs  possessing  a  glandular 
structure,  but  no  excretory  ducts ;  and  which  are  supposed  to  ela- 
borate substances  from  the  blood  to  be  again  applied  to  some  pur- 
pose in  the  organism,  after  resorption  from  their  tissue.  As  thej 
derive  their  designation  from  a  mere  hypothesis,  it  were  doubtless 
better  to  abolish  it  altogether.  "  Ductless  glands"  {lodd  and 
Bowman)  is  a  better  designation. 

The  foilowing  organs  are  referred  at  "the  present  time  to  this  class; 
all  of  which  have  been  described  in  connection  with  other  parts 
and  organs,  except  the  last  four. 

The  anterior  lobe  of  the  pituitary  body  (p.  465);  the  solitary 
follicles  of  the  stomach  and  intestine,  and  the  aggregated  follicles  of 
the  small  intestine  (p.  530);  the  follicular  glands  in  the  root  of  the 
tongue,  the  tonsils,  and  the  pharyngeal  follicles  (p.  573),  and  the 
lymphatic  glands  (p.  510). 

The  spleen,  the  thyroid  body,  the  thymus,  and  the  supra-renal 
glands — still  remain  to  be  described. 


THE   SPLEEN. 


583 


I.  The  Spleen. 

The  spleen  consists  of  a  serous  and  a  fibrous  coat,  and  a  soft 
parenchyma, 

1.  The  seroiis  coat  is  the  peritoneal  investment,  and  adheres  so 
firmly  to  the  fibrous  coat  that  it  can  be  dissected  off'  only  in  frag- 
ments. 

2.  The  fibrous  coat  is  composed  of  areolar  tissue,  and  completely 
invests  the  spleen,  and,  at  the  hilus,  sends  sheaths  into  the  interior 
around  the  vessels,  like  Glisson's  capsule.' 

3.  The  imrenchyma  is  principally  composed  of  (1,)  the  trabeculse, 
inclosing  (2,)  the  pulp,  in  which  (3,)  the  Malpighian  corpuscles  are 
found. 

1.  The  traheculce  are  white,  shining,  flattened  or  cylindrical  bars, 
averaging  y  i  „  to  3'g  of  an  inch,  of  are- 
olar tissue,  attached  to  the  inner  sur-  -^'S-  ^■^*^* 

face  of  the  fibrous  coat,  and  sometimes 
to  the  outer  surface  of  the  sheath  of 
the  vessels,  and  which  unite  to  form  a 
network  extending  through  the  whole 
organ.  The  interstices  in  it  freely 
communicate,  and  contain  the  red  pulp 
and  the  Malpighian  corpuscles.  Be- 
'  sides  the  collagenous  and  elastic  ele- 
ments, the  trabecule  also  contain  many 
peculiar  spindle-shaped  fibres  g^^y  to 
4^^  of  an  inch  long,  and  goVo  o^  ^n 
inch  wide,  with  undulated  ends  and 
prominent  enlargements,  containing 
rounded  nuclei.  Kolliker  at  first  mis- 
took them  for  smooth  muscular  fibres. 
Their  nature  is  not  fully  understood. 
They  are  sometimes  found  coiled  up  in 
cell-like  bodies.     (Fig.  410.) 

2.  The  interspaces  of  the  trabeculse  are  filled  by  the  pulj),  in  which 
the  Malpighian  bodies  are  lodged.  The  pulp  is  a  soft,  reddish  sub- 
stance, consisting  of  three  elements:  1,  the  smallest  bloodvessels; 
2,  microscopic  fibres  and  trabeculce;  and  3,  peculiar  cells.     The  oc- 


Peciiliar  fibres  from  the  pulp  of  the 
human  spleen,  a.  The  same,  free  B. 
One  inclosed  in  a  cell. — Magnified  330 
diameters.     {KolliJcer.) 


'  In  the  ox,  dog,  pig,  ass,  and  cat,  it  contains  smooth  muscular  fibres  also. 


584: 


THE   TISSUES. 


currence  of  extra vasated  blood  in  various  stages  of  metamorphosis 
is  also  so  frequent  as  to  be  almost  regarded  as  a  normal  constituent. 
TKe  vessels  will  be  described  further  on.  The  fine  trabeculae  are 
also  composed  of  areolar  tissue,  and  are  24V o  to  xsV 0  of  9,n  inch  in 
diameter.  The  minute  fibres  are  very  numerous,  and  of  collagenous 
tissue;  some  of  them  being  the  terminations  of  the  vascular  sheaths. 
The  cells  of  the  pulp  (parenchymal  cells)  (Fig.  411),  are  round, 
uni-nucleated,  ^^jV it  to  2 4VTT  of  an  inch  in  diameter,  and  apparently 

Fig.  411. 


^  o  ®  *  <^ 


Pulp  of  )uiman  pplecn.    a,  a.  Blood-corpuscles.    6,6.  Dotted  nuclei,    c,  c.  Nucleated  vesicles,    d,  d. 
Colored  masses  of  hsematine.    (Cfray.) 


like  those  of  the  Malpighian  bodies,  soon  to  be  described.  More 
than  in  the  latter  also,  free  nuclei  are  mixed  with  them.  Pale, 
round,  homogeneous  bodies  also  are  found,  somewhat  larger  than 
blood-corpuscles,  resembling  free  nuclei,  or  homogeneous  nuclei 
surrounded  by  a  delicate  investment;  pale  larger  cells,  up  to  tsVtj 
of  an  inch  in  diameter,  with  one  or  more  nuclei — and  cells  with 
dark  colorless  fat-granules.  These  elements  also  exist,  but  in  less 
extent,  in  the  Malpighian  corpuscles.  The  cells  are  united  by  a 
reddish-yellow  fluid ;  and,  together  with  the  latter,  constitute  about 


THE   SPLEEN. 


685 


one-half  the  mass  of  the  spleen.  There  are  no  special  investments 
around  these  parenchymal  cells.  They  lie  in  direct  contact  with 
the  sheaths  of  the  vessels,  the  trabeculae,  and  the  sheaths  of  the 
Malpighian  bodies. 

The  red  pulp  of  the  spleen  presents  different  shades  at  different 
times,  as  they  depend  on  the  blood-corpuscles  in  its  vessels;  and 
which  present  all  the  various  stages  of  metamorphosis.  Kcilliker 
and  Gray'  describe  round  cells  3  4Vir  to  gJ,-^  of  an  inch  in  diameter, 
holding  more  or  less  metamorphosed  blood-corpuscles,  and  con- 
taining 1  to  10  or  even  20  of  them.  These,  with  other  masses  of 
corpuscles  without  an  investment,  finally  become  converted  into 
pigment-masses  and  pigment-cells,  after  undergoing  various  changes 
in  color.  Finally,  however,  the  last  pass  into  perfectly  colorless 
cells.  The  more  recent  investigations,  however,  of  Kemak  and  T. 
Wharton  Jones,  throw  doubt 

upon  the  existence  of  these  Fig-  412. 

red-corpuscle-inclosing  cells; 
especially  in  the  normal  state. 
Keddish  crystalline  forms 
(htematine)  are  also  occasion- 
ally found  in  the  pulp,  ((rra?/.) 

3.  The  Malpighian  hodies 
are  white,  rounded  masses  im- 
bedded in  the  red  substance 
of  the  spleen,  and  connected 
with  the  smallest  arteries. — 
Kolliker  states  that  they 
are  constant  only  in  healthy 
subjects,  and  are  found  rare- 
ly, or  not  at  all,  in  those  dy- 
ing of  disease,  or  after  long 
fasting.  Gray,  however,  as- 
serts that  they  are  always 
present  in  the  mammalia, 
though  not  always  visible  to 

the  naked  eye.  They  are  yi  o  to  g'g  (average  t^^)  of  an  inch  in  dia- 
meter ;  being  larger  after  food  has  been  taken.  Though  imbedded 
in  the  red  pulp,  and  hardly  separable  from  it,  they  are  always  at- 


A  portion  of  the  splenic  artery,  its  ramifications  be- 
ing studded  with  Malpighian  corpuscles  (dog).  (Mag- 
nified 10  diameters.) 


On  the  Structure  and  Use  of  the  Spleen.     London,  1854. 


586 


THE   TISSUES. 


Fig.  413. 


tached  to  an  arterial  twig,  and  either  rest  upon  it  laterally,  or  are 
situated  at  its  angle  of  division,  or  transfixed  by  the  artery  itself. 
(Fig.  412.)  Arteries  of  g^^  to  3^^  of  an  inch  have  5  to  10  corpus- 
cles ;  and  each  cubic  line  appears,  on  an  average,  to  contain  one  of 
them  {Kdlliker\  they  constituting  ^  to  ^  of  the  whole  pulp.  [Gray.) 
Gray  describes  the  Malpighian  bodies  as  consisting  of — 1st,  a 
closed  capsule  intimately  connected  with  the  sheath  of  the  vessel, 

formed  of  simple  membrane,  and 
T5^i)(j  to  g^Vx)  of  an  inch  thick 
{Kblliker)  (Fig.  413);  and,  2dly,  its 
contents,  a  viscid  grayish  substance, 
consisting  of — Is^,  an  amorphous, 
finely  granular  matter,  containing 
dispersed  nuclei ;  2dhj,  nuclei  like 
those  of  the  red  pulp,  ^oVtt  to  5^00 
of  an  inch  in  diameter;  and,  Sdly, 
a  few  nucleated  cells,  ^xrViy  of  ^^ 
inch  in  diameter.  No  blood-cor- 
puscles, either  free  or  in  cells, 
are  here  met  with.  Remak  and 
Leidy,  however,  have  not  found  the 
distinct  capsule  above  described ; 
but  assert  that  the  Malpighian  corpuscles  pass,  in  man  at  least,  into 
the  red  pulp.  The  external  surface  of  the  closed  capsule  is  covered 
by  a  plexus  of  capillaries.  (Gray.)  Kolliker's  idea,  of  a  clear  fluid 
within  the  capsule,  is  contradicted  by  most  recent  observers. 

Vessels.— The  subdivisions  of  the  splenic  artery  are  very  nume- 
rous, and  assume  the  peculiar  arrangement  shown  in  Fig.  412  ;  and 
finally  merge  into  capillaries  ^^Vo  to  34^1?  of  an  inch  in  diameter, 
constituting  a  network  throughout  the  pulp  and  around  the  Malpi- 
ghian corpuscles  (Fig.  414),  and  traversing  the  substance  of  the  latter 
also.  {Drs.  Sanders  and  Huxley)  The  veins  present  no  peculiarity 
requiring  mention  here.  The  lymphatics  are,  comparativel}'^,  very 
few;  and  the  lymph  of  the  deep-seated  ones  contains  blood-cor- 
puscles, perhaps  from  rupture  of  minute  bloodvessels  (p.  148).  In 
diseased  spleens,  no  trace  of  the  superficial  lymphatics  (those  be- 
tween its  two  coats)  can  usually  be  detected.  The  nerves,  consisting 
of  many  fine  and  a  few  thick  fibres,  are  derived  from  the  splenic 
plexus,  and  accompany  the  branches  of  the  artery  into  the  interior 
of  the  or";an. 


A  Malpighian  corpnsele  from  the  spleen  of 
;ui  ox.  a.  Wall  of  the  corpuscle.  6.  Con- 
tputs.  d.  Sheath  of  the  artery,  e.  Wall  of 
the  artery. — Alagnified  150  diameters.  (K'tlli- 
h-er.) 


FUNCTION"   AND   DEVELOPMENT   OF   THE   SPLEEN.       587 
Fig.  414. 


The  connection  of  a  Malpighian  corpuscle  with  the  neighboring  Tessels.  It  is  placed  at  the  angle 
of  bifurcation  of  one  of  the  small  arteries  ;  its  external  surface  being  covered  by  a  close  and  delicate 
capillary  plexus,  while  its  circumference  is  invested  by  a  mesh  of  large  veins,  radiating  from  its 
margin  in  all  directions.    The  capillary  plexus  of  the  pulp  is  also  shown.  (Grray.) 

Function  of  the  Spleen. 
Mr.  Gray  maintains  that  the  spleen  regulates  both  the  quantity 
and  the  quality  of  the  blood ;  it  being  a  diverticulum  of  the  hepatic 
circulation,  while,  at  the  same  time,  the  Malpighian  corpuscles,  more 
especially,  elaborate  albuminous  substances  from  the  blood  soon  after 
digestion,  store  them  up  for  the  time  being,  and  again  return  them 
to  the  blood  when  needed.  Though  these  statements  may  need 
some  qualification,  a  comparison  of  the  blood  in  the  splenic  veins 
(p.  175)  with  that  in  its  artery  confirms  the  idea  that  the  spleen  is 
a  blood-making  organ,  except  so  far  as  the  colored  corpuscles  are 
concerned — these  being  actually  disintegrated  in  it. 

Development  of  the  Spleen. 
The  spleen  is  developed,  independently  of  the  surrounding  or- 
gans, at  the  end  of  the  second  month,  from  a  blastema.     The  Mai- 
pighian  bodies  are  last  formed,  and  are  much  smaller  at  birth  than 
afterwards. 


588 


THE   TISSUES. 


Fig.  415. 


II,  The  Thykoid  Gland. 

The  tliyroid  gland  consists  of  closed  gland- vesicles  g^o  to  ^^^j  of 
an  inch  in  diameter,  surrounded  by  a  fibrous  stroma,  and  collected 
into  rounded  or  polygonal  lobules  ^'g  to  ^^  of  an  inch  in  diameter, 
which  are  associated  into  lobes ;  and  finally  the  latter,  invested  by 
a  fibrous  membrane,  constitute  the  whole  organ. 

Little  need  be  said  of  the  fibrous  tissue  or  stroma,  since  it  is 
mere  common  areolar  tissue.  Only  the  vesicles  need  a  special  de- 
scription. 

The  gland-vesicles  present  such  varied  conditions  of  structure, 
that  it  is  not  easy  to  decide  what  is  their  normal  state.  They  con- 
sist— Ist^  of  a  basement-mem- 
brane lying  on  the  connective 
tissue  between  them;  2dly,  of 
an  epithelium;  and,  3t^?y,  fluid 
contents.  The  basement-mem- 
brane is  15^00  of  an  inch 
thick,  and  presents  no  pecu- 
liarities. The  epithelium  con- 
sists of  a  single  layer  of  po- 
lygonal, finely  granular  cells, 
?o'oo  to  oo'oij  of  an  inch  in 
diameter,  with  simple  nuclei. 
(Fig.  415.)  The  fluid  con- 
tained in  the  cells  is  clear, 
somewhat  viscous,  with  a  tinge 
of  yellow,  and  highly  albu- 
minous. 

If,  however,  the  organ  be 
changed  from  its  normal  state,  different  conditions  are  presented. 
Frequently  no  epithelium  is  met  with,  but  only  a  fluid  mixed  with  ' 
minute  granules,  and  free  nuclei.  The  vesicles  are  also  more  or 
less  filled  with  a  colloid  substance  in  the  form  of  transparent,  amor- 
phous, light-yellowish,  soft  masses.  This,  filling  the  vesicles,  trans- 
forms the  latter  into  cysts  of  y||,  to  ^^  of  an  inch,  in  which  the 
epithelium  is  no  longer  distinct;  and  which,  causing  the  stroma  to 
disappear  by  their  pressure,  ultimately  coalesce  into  larger  sinuous 
cavities.     (Fig.  416.) 


Some  gland-vesicles  from  the  thyroid  gland  of  a 
child,  a.  Connective  tissue  between  them.  h.  Mem- 
brane of  the  gland-vesicles,  c.  Their  epithelium. 
(KoUiker.) 


THE   THYROID   GLAND. 
Fig.  416. 


589 


26.384 
1.70 
.50 
.816 

onally  numerous. 


The  vesicles  of  the  thyroid  gland,  filled  with  colloid  matter. — Magnified  50  diameters. 

{Kolliker.) 

The  following  is  Dr.  Beale's  analysis  of  the  thyroid  body : — 

Water 70.60 

Fibrinous  and  albuminous  matter,  vessels, 

and  fat   . 
Extractive  matter       .... 

Alkaline  salts 

Earthy  salts       .         .         .         . 

The  bloodvessels  of  the  thyroid  are  disproporti 
The  terminal  arteries  are  distributed  in  the  stroma  between  the 
vesicles,  and  end  in  a  capillary  plexus  around  each  of  them,  resem- 
bling that  of  the  air-cells  of  the  lungs,  except  that  it  is  less  close. 
The  veins  only  partially  accompany  the  arteries,  much  exceeding 
them  in  number.  Of  the  considerable  number  of  lymphatics^  the 
relations  in  the  interior  are  unknown.  The  few  nerves  contain  only 
vascular  nerve-fibres  from  the  cervical  portions  of  the  sympathetic. 
{Kolliher?) 

The  function  of  the  thyroid  is  unknown.  It  is  probably  a  diver- 
ticulum to  the  cerebral  circulation ;  and  is  developed  from  an  offset 
from  the  anterior  wall  of  the  pharynx. 

Pathological  enlargements  of  the  thyroid  (bronchocele)  are  very 
common.  These  may  be  due — Is^,  to  numerous  dilatations  of  the 
smaller  vessels,  the  bursting  of  which  may  also  produce  apoplectic 
cysts,  to  which  fresh  extravasations,  or  exudations  and  cretification 
of  the  vessels  may  be  added;  or,  2dly,  to  an  actual  hypertrophy  of 
the  glandular  elements,  or  a  production  of  new  gland-vesicles. 


590  THE   TISSUES. 


III.  The  Thymus  Gland. 

The  thymus  is  an  organ  more  especially  of  foetal  and  infantile 
life.  It  consists  of  lobules  grouped  around  a  central  canal,  which 
is  generally  spirally  convoluted.  The  lobules  are  collected  into 
lobes;  while  the  latter,  invested  by  areolar  tissue,  constitute  the 
whole  organ. 

The  lobules  are,  however,  composed  of  smaller  hollow  subdivi- 
sions, and  the  latter  of  rounded  corpuscles,  like  gland-vesicles, 
which  give  the  exterior  of  the  lobules  a  delicate  mosaic  aspect,  not 
unlike  that  of  the  lungs.  (Fig.  417.)  These  corpuscles  are,  how- 
Fig.  417. 


A  section  of  the  thymus  gland  at  the  eighth  montli,  showing  its  structure  ;  from  a  preparation  of 
Sir  A.  Cooper.  1.  The  cervical  portions  of  the  gland  ;  the  independence  of  the  two  lateral  glands  is 
well  marked.  2.  Secretory  follicles  seen  upon  the  .surface  of  the  .section  ;  these  are  observed  in 
all  parts  of  the  section.  3,  3.  The  pores  or  openings  of  the  secretory  follicles  and  pouches  are 
seen  covering  the  whole  internal  surface  of  the  great  central  cavity  reservoir.  Tho  continuity  of  the 
reservoir,  in  the  lower  or  thoracic  portion  of  the  gland,  with  tho  cervical  portion,  is  seen  in  tho  figure. 

ever,  not  vesicles,  but  solid  bodies,  cohering  intimately  towards  the 
cavities,  though  separated  from  each  other  on  the  outer  side. 

Each  lobule  is  inclosed  in  a  thin,  almost  homogeneous,  mem- 
brane, s^iu^  to  jjixsv^  of  ^^  if^ch  thick.  Within  this,  and  between 
it  and  the  cavity  of  the  lobule,  lies  a  grayish-Avhite  soft  substance, 
7'^  to  ^'b  of  an  inch  thick,  consisting  of  free  nuclei  and  minute  cells, 
among  which  bloodvessels  and  a  small  amount  of  white  fibrous 
tissue  are  sent;  and  thus  a  structure  is  presented  resembling  that  of 
the  contents  of  the  follicles  of  Peyer  (p.  530). 

The  cells  and  nuclei,  however,  of  the  thymus-lobules,  with  a 
small  quantity  of  a  connecting  fluid,  constitute  the  main  bulk.   The 


THE   THYMUS   GLAND. 


591 


Fig.  418. 


cells  are  much  less  numerous  than  the  free  nuclei,  and  from  ^^j'tj^j 
to  jiiss  of  ^^  iii'^^  i'^  diameter;  the  latter  being  g^V?y  to  i^^^jj  of 
an  inch. 

The  arteries  (Fig.  418)  are  sent  from  the  external  surface  through 
to  tlie  internal  cavity,  and  there  ramify  in  a  delicate  expansion  of 
areolar  tissue  lining  it.  From  this 
arterial  plexus,  branches  enter  the  ca- 
vity of  each  lohule,  and  form  a  capillary 
plexus  in  their  external  portion,  or 
the  gland-corpuscles,  entirely  filling 
them,  but  never  extending  further  than 
to  the  inner  surface  of  the  homogeneous 
membrane  investing  them. — The  fibres 
above  mentioned  support  the  capilla- 
ries just  described,  and  require  no  spe- 
cial description. — The  lymphatics  are 
numerous;  and  nerves  accompany  the 
arteries,  though  not  yet  traced  to  their 
terminations. 

The  cavities  of  the  thymus  inclose  a 
grayish- white  or  milky,  faintly  acid, 
albuminous  fluid,  containing  numerous 
nuclei,  isolated  cells,  and  Sometimes 
concentric  corpuscles,  next  to  be  de- 
scribed. 

Between  the  ages  of  12  and  20 
years,  involution  of  the  thymus  com- 
mences. During  this,  peculiar  spheri- 
cal bodies  are  found  in  the  substance  of  the  lobules,  called  the  con- 
centric corpuscles.  These  (first  noticed  by  Hassall  and  Virchow) 
are:  1.  Simple,  so'oo  to  yn'^^  of  an  inch  in  diameter,  with  a  thick 
concentrically  striated  membrane  and  a  granular  substance  within, 
appearing  sometimes  as  a  nucleus,  at  others  as  a  cell;  2.  Compound, 
■^-ho  to  Y^^  of  an  inch  in  diameter,  and  consisting  of  several  simple 
corpuscles  inclosed  in  a  common  laminated  envelop.  By  the  40th 
year,  the  thymus  is  usually  entirely  removed. 

The  function  of  the  thymus  is  not  certainly  known.  Mr.  Sim.on 
considers  it  "  a  sinking  fund  in  the  service  of  respiration."  It  is 
developed  by  two  tubular  olBfsets  from  the  larynx,  containing  blas- 
tema.   It  is  not  stationary  after  birth,  as  sometimes  stated,  but  grows 


Transverse  section  of  an  injected  lob- 
ule of  the  thymus  of  a  child,  a.  Mem- 
brane of  the  lobule.  6.  Membrane  of 
the  gland-corpuscles,  c.  Cavity  of  the 
lobule  from  which  the  larger  vessels 
branch  out  into  the  corpuscles,  on  th^ 
surface  of  which  they  terminate,  occa- 
sionally forming  loops.     (30  diameters.) 


592 


THE   TISSUES. 


Fig.  419. 


considerably  up  to  the  2d  year.    Subsequently  it  becomes  atropbied, 
and  finally  disappears,  as  above  mentioned. 

IV.  The  Supra-Kenal  Glands. 
These  bodies  are  usually  classed  with  the  blood-vascular  glands, 
though  they  do  not  strictly  belong  to  this  class.     They  consist  (1,) 

of  a  fine,  but  thin  coat  of  areolar  tis- 
sue, and  (2,)  the  proper  parenchyma. 
The  former  needs  no  special  descrip- 
tion. 

The  parenchyma  is  divisible  into  two 
parts,  the  cortical  and  the  medullary 
portions.  (Fig.  419.)  1.  The /ormer  is 
of  a  whitish-yellow  color  (more  nearly 
brown  in  its  innermost  third),  g'g  to 
2^4  of  an  inch  thick;  easily  torn  in  the 
direction  of  its  thickness,  and  when 
torn,  presenting  a  fibrous  aspect. 

2,  The  medullary  substance  is  of  a 
brighter  color  than  the  cortical,  being 
grayish -white  with  a  tinge  of  red, 
though  it  may  become  darker  when 
its  veins  afe  full  of  blood.  It  is  softer 
than  the  cortical  substance,  and  only 
7^2  to  3^6  of  an  inch  thick  at  their  bor- 
ders; while  it  is  1  to  1|  line  in  the 
middle,  and  the  lower  and  inner  half 
of  these  organs. 

In  their  intimate  structure  the  cor- 
tical and  the  medullary  portions  are 
entirely  dissimilar.  The  cortical  substance  consists  of  very  nu- 
merous compartments  (cortical  cylinders,  Kblliker),  ^l-;^  to  even 
j^^  of  an  inch  across,  formed  by  interlacements  of  areolar  tissue, 
and  extending  through  the  entire  thickness  of  the  cortex;  contain- 
ing a  granular  substance,  subdivided  by  delicate,  oblique,  or  trans- 
verse dissepiments.  (Fig.  420.)  These  generally  contain  nothing 
but  rounded  angular  cells,  ^^Vtt  to  tAtt  of  an  inch  in  diameter. 
In  the  inner  brown  layer  of  the  cortex,  the  cells  are  entirely  filled 
with  brown  pigment-granules. 

The  medullary  substance  also  has  a  stroma  of  areolar  tissue  pro- 


Transverse  section  of  the  supra-renal 
body  of  the  calf,  treated  with  soda.  a. 
Cortex,  h.  Medulla,  c.  Central  vein, 
surrounded  with  some  cortical  sub- 
stance, d.  Three  entering  nerves,  e. 
Nerves  and  their  distribution  in  the  in- 
terior.    (Magnified  about  15  diameters.) 


THE    SUPRA-RENAL    GLANDS. 


593 


Fig.  420. 


Portion  of  a  vertical  section  through 
the  cortex  of  the  supra-renal  body  in 
man.  a.  Septa  of  connective  tissue,  b. 
Cortical  cylinder  whose  composition 
from  cells  is  more  or  less  distinctly 
manifest.     (Magnified  300  diameters.) 


longed  from  tlio  cortical  larnelUe,  and  pervading  the  whole  interior, 
forming  a  network  with  rather  wide  meshes.  This  is  filled  by  a 
pale,  finely  granular  substance,  contain- 
ing pale  cells,  -xshr)  to  ^-^^  of  an  inch  in 
diameter,  resembling  the  nerve-cells  of 
the  central  organs,  though  they  cannot 
be  definitely  declared  to  be  such.  [Kol- 
liker.) 

The  bloodvessels  of  the  supra-renal 
glands  are  very  numerous.  Some- 
times even  twenty  arterial  trunks  enter 
one  of  these  glands.  A  capillary  plexus 
with  elongated  meshes  exists  in  the 
cortical  substance,  and  one  with  round- 
ed interstices  in  the  medullary.  Thus 
the  cortical  cylinders  are  surrounded 
by  blood  on  all  sides ;  and  this  capil- 
lary plexus  joins  that  of  the  medul- 
lary substance,  formed  principally  by  arteries  penetrating  at  once 
into  the  latter.  A  few  lymphatics  are  found  on  the  surface  of  the 
organ,  but  more  in  its  interior. 

The  nerves  of  the  supra-renal  glands  are  very  numerous;  being 
derived  from  the  semi-lunar  ganglion,  and  the  renal  plexus ;  and 
also,  to  a  small  extent,  from  the  pneumogastric  and  the  diaphragm- 
atic. {Bergman)}).  Kolliker  has  counted  33  trunks  entering  the  right 
supra-renal  gland,  varying  from  ^\  to  g^^  of  an  inch  in  diameter; 
and  found  that  almost  without  exception,  they  were  constituted  of 
dark-bordered,  finer,  and  medium-sized,  or  even  thick,  nerve-fibres; 
and  were  furnished  with  isolated  larger  or  smaller  ganglia.  They 
appear  to  be  all  destined  for  the  medullary  substance,  where  there 
is  an  .extremely  rich  nervous  plexus;  the  terminations  of  the  fibres 
being,  however,  nowhere  perceptible. 

The  supra-renal  glands  are  developed  simultaneously  with  the 
kidneys,  but  independently  of  them;  and  are  originally  larger  than 
they.  The  first  appearance  and  growth  of  the  blastema  where  they 
are  found  is  unknown. 

Of  the  function  of  the  supra-renal  glands,   nothing  positive  is 
known.     They,  however,  have  pretty  certainly  no  phj^siological 
connection  with  the  kidneys.     Kolliker  thinks  that  while  the  cor- 
tical portion  may  belong  to  the  class  of  blood-vascular  glands,  the 
38 


594 


THE   TISSUES. 


medullary  portion  is  physiologically  distinct  from  the  former,  and 
must  be  regarded  as  an  apparatus  pertaining  to  the  nervous  system, 
as  Bergmann  suggested.  And  Leydig's  recent  investigations  in 
regard  to  the  structure  of  these  organs  in  fishes  and  reptiles,  have 
led  him  to  conclude  that  they  have  the  same  relation  to  the  gan- 
glia of  the  sympathetic  nerves,  that  the  pituitary  body  bears  to  the 
brain  (p.  4:Qd). 


CHAPTER    XVIII. 

THE    ORGANS   OF   THE    SENSES. 

The  histological  elements  of  the  organs  of  the  senses  have  already 
been  mostly  described. 

I.  The  organ  of  touch — the  skin — in  Chap.  XI.  (pp.  476 — 494.) 

II.  The  organ  of  taste — the  mucous  membrane  of  the  tongue — 
pp.  515-18,  and  Figs.  344  to  347. 


Fi-  421. 


General  view  of  the  external,  internal,  aiul  middle  ear,  as  seen  in  a  prepared  section  through  a, 
the  auditory  canal ;  6,  the  tympanum  or  middle  ear  ;  c,  Eustachian  tube,  leading  to  the  pharynx  ; 
d,  cochlea;  c,  Boniicircular  canals,  and  vestibule,  seen  on  their  exterior  as  brought  into  view  by 
dissecting  away  the  surrounding  petrous  bono.  The  styloid  process  projects  below ;  and  the  inaer 
surface  of  tlie  carotid  canal  iaseon  above  the  iMistachian  tube.     (From  Scdrpa.) 


THE    MEMBRANOUS    LABYRINTH. 


595 


III.  The  organ  of  smell — the  olfactory  nerves  and  the  mucous 
membrane  of  the  nasal  passages — p.  448,  and  Figs.  200-2. 

IV.  The  organ  of  hearing — so  far  as  the  acoustic  nerve,  and  the 
distribution  of  its  cochlear  branch  are  concerned — has  been  de- 
scribed on  p.  453,  Figs.  300  and  301. 

Fig.  422. 


The  soft  parts  of  the  vestibule  taken  out  of  their  bony  case,  so  as  to  show  the  distribution  of  the 
nerves  in  the  ampuUas.  1.  The  superior  semicircuhir  membranous  canal  or  tube.  2.  The  external 
semicircular  tube.  3.  The  inferior  semicircular  tube.  4.  The  tube  of  union  of  the  superior  and  in- 
ferior canals.  5.  The  saccules  ellipticus.  6.  The  sacculus  sphericus.  7.  The  portio  dura  nerve,  f . 
The  anterior  fasciculus  of  the  auditory  nerve.  9.  The  nerve  of  the  sacculus  sphericus.  10,10.  The 
nervous  fasciculi  to  the  superior  and  external  ampuUte.  11.  The  nerve  to  tho  sacculus  ellipticus. 
12.  The  posterior  fasciculus  of  the  auditory  nerve  furnishing  (13),  the  filaments  of  the  sacculus 
sphericus,  and  It,  the  filaments  of  the  cochlea,  cut  off. 

Fig.  423. 


The  ampulla  of  the  external  semicircular  membranous  canal,  showing  the  mode  of  tormluation  of 

its  nerve. 


596 


THE    TISSUES. 


A  section  of  both  the  external  and  internal  ear  is  shown  by  Fig. 
421. 

The  membranous  labyrinth,  and  the  terminations  of  the  vesti- 
bular nerve,  are  shown  by  Figs.  422,  423. 

Flff.  424. 


A  view  of  tho  laljyrinth  of  the  left  side,  laid  open  iu  its  whole  extent  so  as  to  show  its  structure. 
Magnified  about  12  diameters.  1.  The  thickness  of  the  outer  covering  of  the  cochlea.  2,  2.  The 
scala  vestibuli,  or  upper  layer  of  the  lamina  spiralis.  3,  3.  The  scala  tympani  or  lower  layer  of  tho 
lamina  spiralis.  4.  The  hamulus  cochleae.  5.  Centre  of  the  infundibulum.  6.  Foramen  opening 
into  the  tympanum.  7.  The  thickness  of  the  outer  layer  of  the  vestibule.  S.  The  foramen  rotund- 
urn.  9.  The  fenestra  ovalis.  10.  The  orifice  of  the  aqueduct  of  the  vestibule.  11.  The  inferior 
semicircular  canal.  12.  The  superior  semicircular  canal.  13.  The  external  semicircular  canal.  14. 
The  ampulla  of  the  inferior  canal.  15.  The  ampulla  of  the  superior  canal.  16.  The  common  orifice 
of  the  superior  and  inferior  canals.    17.  The  ampulla  of  the  external  canal. 

Fig.  425. 


An   anterior  view  of  the  external  car,  as  well  as  of  the  meatus  auditorius,  labyrinth,  &c.    1. 
The  opening  of  the  ear  at  the  bottom  of  the  concha.     2.  Tlio  raeatus  auditorius  extcrnus,  or  carti- 
laginous canal.    3.  The  mcmbrana  tympani  stretched  upon  its  ring.    4.  Tho  malleus.    5.  The  stapes. 
The  labyrinth. 


MEMBRANES   OF   THE    EYE. 


597 


The  whole  labyrinth  (internal  ear),  consisting  of  the  cochlea  and 
semicircular  canals,  laid  open,  is  shown  by  Fig.  424.  Its  relations 
to  the  external  and  middle  ear  are  seen  in  Fig.  425. 

Y.  The  Eye. 

Some  of  the  structural  elements  of  the  eye  have  already  been 
spoken  of  (pp.  449-53) ;  and  the  rest  will  be  described  here. 

'  I.  Membranes  of  the  Eye. 

A  section  of  tlie  eyeball  is  shown  by  Fig.  426.  The  three  mem- 
branes of  its  posterior  seven-eighths,  or  more,  are  the  tunica  scle- 
rotica, the  choroid,  and  tlie  retina;  while  the  cornea  is  seen  project- 
ing in  front,  and  the  iris  is  represented  by  6,  in  the  figure. 

1.  The  sclerotic  coat  is  composed  of  white  fibrous  tissue  and  a 
few  elastic  fibres  (p.  279);  and  is  shown,  together  with  the  choroid, 
by  Fig.  427. 

2.  The  choroid cosit  is  continuous  in  front  with  the  iris;  a  narrow 
ring  of  white  fibrous  tissue — the  ciliary  ligament — connecting  them 

Fiff.  426. 


A  longitudinal  section  of  tho  globe  of  the  eye.  1.  Tlie  sclerotic,  thicker  behind  than  in  front.  2. 
The  cornea  apparently  received  within  the  anterior  margin  of  the  sclerotic,  and  connected  Tvith  it  by 
moans  of  a  bevelled  edge,  though  really  continuous  with  it.  3.  Tho  choroid,  connected  anteriorly 
with  (4),  the  ciliary  ligament  and  (5),  the  ciliary  processes.  6.  The  iris.  7.  The  pupil.  8.  The 
third  layer  of  the  eye,  the  retina,  terminating  anteriorly  (ora  serrata)  at  the  commencement  of  tho 
ciliary  processes.  9.  The  canal  of  Petit,  which  encircles  the  lens  (12)  ;  the  thin  layer  in  front  of 
this  canal  is  tho  zonula  ciliaris,  a  vascular  prolongation  of  tho  retina  to  the  lens.  10.  The  anterior 
chamber  of  tho  eye  containing  the  aqueous  humor  ;  tho  lining  membrane  by  which  the  humor  is 
secreted  is  represented.  11.  Posterior  chamber.  12.  The  lens  more  convex  behind  than  before,  and 
inclosed  in  its  proper  capsule.  13.  Tho  vitreous  humor  inclosed  in  the  hyaloid  membrane,  and  its 
cells  formed  in  its  interior  by  that  membrane.  14.  A  tubular  sheath  of  the  hyaloid  membrane, 
which  serves  for  the  passage  of  the  artery  of  the  capsule  of  tho  lens.  15.  Poriueurium  of  the  optic 
nerve.     16.  Tho  artoria  centralis  retinro,  imbedded  in  its  centre. 


598  THE   TISSUES. 

firmly  at  their  union,  with  the  sclerotica.  (Figs.  427-8.)  The  choroid 
itself  is  essentially  a  thin  lamina  of  capillaries,  with  arteries  and 
veins  external  to  it,  and  lined  on  its  internal  surface  by  a  single 
layer  of  nucleated  pigment-cells  of  a  pentagonal  or  hexagonal  shape. 
(Fig.  69.)  Between  the  capillary  network  and  the  arteries  and 
veins,  as  well  as  among  the  veins  themselves,  there  is  also  an  abun- 
dance of  pigment-cells.  The  internal  plexus  of  capillaries  is  termed 
the  tunica  Ruyscldana.  (Fig.  429.)  The  veins  of  the  choroid  are 
arranged  in  beautiful  curves,  and  are  termed  vasa  vorticosa.  For 
I  of  an  inch  behind  the  ciliary  ligament,  the  choroid  coat  is  sepa- 
rated from  the  sclerotic  by  the  ciliary  muscle,  consisting  of  smooth 
muscular  fibres.  (Fig.  428.)  The  last  is  covered  externally  by  the 
ciliary  processes,  which  are  projecting  folds  of  the  choroid,  lodged 
in  similar  folds  upon  the  vitreous  body — the  ciliary  zone.  They 
also  are  very  vascular  (Fig.  430),  and  contain  an  abundance  of  ir- 
regular pigment-cells.  The  ciliary  nerves  are  seen  on  their  way  to 
the  iris  in  Fig.  427. 

Fi".  427. 


Choroid  and  iris  exposed  by  turning  aside  the  sclerotica,  c,  c.  Ciliary  nerves  branching  in  the 
iris.  d.  Smaller  ciliary  nerve,  e,  e.  Vasa  vorticosa.  h.  Ciliary  ligament  and  muscle.  Jr.  Con- 
verging fibres  of  the  greater  circle  of  the  iris.  I.  Looped  and  knotted  form  of  these  near  the  pupil, 
with  the  converging  fibres  of  the  lesser  circle  of  the  iris  vrithin  them.  o.  The  optic  nerve.  (From 
Zinn.) 

3.  The  retina  has  already  been  described  (pp.  450-3,  and  Figs. 
295  to  299).  The  relations  of  the  crystalline  lens  and  the  vitreous 
body  are  shown  by  Fig.  431. 

4.  The  cornea  has  already  been  described  at  length  (pp.  280-1, 
and  Figs.  178  to  180). 


^MEMBRANES    OF   THE    EYE. 


599 


5,  The  iris  is  a  process  of  the  choroid,  and  continuous  behind 
with  the  ciliary  processes;  though  modified  in  structure.     For  it 


Fig.  428. 


Lig.  42^). 


Pig.  428.  Diagram  to  sho-n-  the  position  and  action  of  the  ciliary  muscle,  a.  Sclerotic,  h.  Cornea, 
e.  Choroid,  separated  a  little  from  the  sclerotic,  d.  Situation  of  the  ciliary  ligament,  and  point  from 
which  the  ciliary  muscle  radiates,  e.  Iris.  n.  Lens  connected  with  the  ciliary  processes  of  the 
anterior  wall  of  the  canal  of  Petit,  the  situation  of  which  is  marked  by  the  *.  (Magnified  3  dia- 
meters.) 

Pig.  429.  Capillary  network  in  choroid  coat  of  the  eye. 


has,  1,  a  stroma,  mostly  of  collagenous  tis- 
sue ;  2,  smooth  muscular  fibres ;  and  3,  a 
layer  of  cells  on  both  its  anterior  and  its 
posterior  surface.  The  muscular  fibres 
^orm  (1,)  a  distinct  occlusor  of  the  pupil 
{sphincter  pupillce)  in  the  form  of  a  smooth 
ring  4^g  of  an  incli  wide,  close  to  the  edge 
of  the  iris.  There  is,  besides,  another  very 
narrow  ring  ^|  ^  of  a  line  wide.  (2.)  They 
also  form  numerous  slender  fasciculi,  but 
not  a  distinct  layer,  extending  from  the 
outer  margin  of  the  iris  to  the  sphincter 
pupillce,  into  the  border  of  which  they  are 
inserted,  constituting  the  dilator  pupillm. 

The  layer  of  cells  on  the  posterior  sur- 
face of  the  iris,  constitutes  the  uvea;  they 
being  closely  filled  pigment-cells.  The 
anterior'  layer  of  cells  is  a  simple  scaly 
epithelium  without  pigment-granules. — 
The  color  of  the  iris  in  blue  eyes  depends 
merely  upon  the  pigment  in  the  uvea,  seen 
through  the  substance  of  the  iris;  in  hazel 


Vessels  of  the  choroid,  ciliary 
processes,  and  iris  ;  inner  surface. 
a.  Portion  of  the  capillary  net- 
work, or  tunica  Ruyschiana.  h. 
Ciliary  processes,  c.  Portion  of 
the  iris.  From  an  infant.  (After 
Arnold. — Magnified  14  diameters. 


6'>0  THE    TISSUES. 

and  black  eyes,  the  pigment  also  exists  in  tlie  stroma  and  among 
the  other  elements  of  the  iris  itself. 

Fig.  431. 


Position  of  the  Ions  (6)  in  the  vitreous  humor,  shown  by  an  imaginary  section.     The  dark  triangular 
space  on  each  side  of  the  lens  is  intended  to  indicate  the  position  of  the  canal  of  Petit. 

The  bloodvessels  and  the  nerves  of  the  iris  are  numerous.  The 
ciliary  branches  of  the  latter  are  shown  by  Fig.  430. 

II.  Humors  of  the  Eye. 

The  three  humors  of  the  eye  are  the  crystalline  lens,  and  the  vi- 
treous, and  the  aqueous  humor.  Fig.  431  shows  the  relation  of  the 
vitreous  body  and  the  crystalline  lens.  The  aqueous  humor  fills  up 
the  spaces  between  the  crj^stalline  lens  and  the  iris,'  and  (extending 
through  the  pupil)  between  the  iris  and  the  cornea  (Fig,  426);  these 
spaces  being  termed  the  'posterior  and  the  anterior  chambers  of  tha 
eye,     (Figs,  426  and  428.) 

The  aqueous  humor  is  so  called  from  its  resemblance  to  pure 
water.  It  is  afforded  b}'-  the  epithelial  cells  covering  the  anterior 
and  the  posterior  chambers  of  the  eye,  and  is  very  readily  repro- 
duced if  removed  experimentally  in  the  lower  animals.  It  is  one 
of  the  three  refracting  media  of  the  eye. 

The  crystalline  lens  and  the  vitreous  body  require  a  special  de- 
scription. 

1,  The  Crystalline  Lens. 

The  crystalline  lens  consists  of  concentric  lamina3  arranged  like 
the  coats  of  an  onion  (Fig,  432),  which  are  composed  of  elongated, 
flat,  hexahedral  tubes  [not  fibres),  ^gV^  to  ^^Vif  of  ^^  ii^cli  broad, 
and  1-33^  to  g|;y  of  an  inch  thick,  perfectly  transparent,  and  con- 
taining a  clear,  viscous,  albuminous  fluid.     Each  tube  is  slighth' 

'  It  is  very  doubtful  if  any  space  naturally  exists  between  the  iris  and  the  lens. 


THE   CRYSTALLINE   LEX 
Fig.  432. 


601 


a.  Cells  connecting  the  body  of  the  lens  to  its  capsule  (human),  b.  Tubes  of  the  lens,  with 
slightly  sinuous  edges,  c.  Tubes  from  the  ox,  with  finely  serrated  edges,  d.  Tubes  from  the  cod ; 
the  teeth  much  coarser.     (Magnified  320  diameters.) 

serrated  at  its  edges  (Fig.  432),  and,  as  it  enters  into  tlie  formation 
of  a  lamina,  is  surrounded  by  six  others.  Thus  their  transverse 
section  resembles  a  wall  built  of  hexagonal  bricks.  (Fig.  433.) 
The  serrations  are  much  more  beautifully  marked  in  the  lower 

Fig.  433. 


Tubes  of  the  lens.     1.  From  the  ox,  with  slightly  toothed  borders.     2.  Transverse  section  of  the 
lenticular  tubes  of  man  —Magnified  350  diameters.    (KCUiker.) 

animals,  especially  fishes.    (Fig.  432,  d)     The  tubes  are  more  solid, 
slender,  and  opaque  in  the  central  part  of  the  lens. 

The  tubes  lie  with  their  sides  parallel  to  the  surface  of  the  lens, 


602 


THE    TISSUES. 


and,  being  here  less  coherent  than  on  their  largest  surfaces,  they 
are  more  easily  separated  into  laminae  in  this  direction. 

In  the  separate  lamellee,  both  the  superficial  and  the  deeper  tubes 
generally  radiate  from  the  centre  of  the  lens  towards  the  margin, 
and  then  curve  round  upon  the  other  surface,  anterior  or  posterior; 
but  never  extend  through  the  entire  semi-circumference  of  the 
lens.  Indeed,  a  peculiar  appearance  called  the  "star"  is  produced 
where  they  terminate  on  both  surfaces  of  the  lens,  as  shown  by 


Fis.  434. 


i^'^ 


ii|^' 


y 


^•tsmMssM^"' 


Lous  of  the  ailult  (itt'ior  Arnold),  to  gliow  tlii5  "star."     1    Anterior  aspect.     2.  Posterior  aspect.' 

(Kolliker.) 

Fig.  484.  In  these  there  are  no  tubes,  but  a  substance  partly  clear 
and  partly  finely  granular. 

The  cajysule  of  the  lens  is  formed  of  simple  membrane,  and  is 
perfectly  transparent  and  very  elastic.  It  admits  neither  vessels 
nor  nerves  to  the  completely  inclosed  lens.  It  is,  however,  readily 
permeable  to  fluids;  and  it  is  the  transmission  through  it,  after 
death,  of  the  aqueous  humor  of  the  eye,  that  mainly  gives  rise  to 
the  "liquor  Morgagni" — this  not  being  a  normal  condition,  as  has 
been  supposed.  A  single  layer  of  clear,  polygonal,  epithelial  cells, 
however,  covers  the  anterior  half  of  the  inner  surface  of  the  cap- 
sule; and  these,  disintegrated,  also  help  to  form  the  "liquor." 

Chemical  analysis  (of  the  lens)  detects  the  presence  of  crystalline, 
described  on  page  97.     It  contains  about  58  per  cent,  of  Avater. 

The  crystalline  lens  is  not  vascular  at  any  period  of  its  develop- 
ment. The  capsule  is  so,  however,  during  early  foetal  existence; 
the  central  artery  of  the  retina  expanding  upon  its  posterior  layer 
(after  having  traversed  the  vitreous  humor),  and  sending  branches 


THE   VITREOUS   BODY.  603 

round  its  margin  to  unite  with  twigs  from  tbe  ciliary  processes 
upon  tlic  anterior  surfiice.  Tlie  loops  of  the  latter  gradually  retire 
from  the  centre  towards  the  margin,  and  finally  the  posterior  layer 
also  ceases  to  be  vascular.  In  inflammatory  conditions,  however, 
the  vascularity  may  return. 

Uses. — The  crystalline  lens  is  of  the  highest  importance  as  one 
of  the  refracting  media  of  the  eye. 

The  fibres  of  the  crystalline  lens  are,  apparently,  developed  ori- 
ginally from  cells  like  those  shown  in  Fig.  432. 

The  groivth  of  the  lens  is,  probably,  secured  b}'  the  absorption, 
through  its  capsule,  of  the  aqueous  or  the  vitreous  humor.  {K'ol- 
Ulcer) 

The  crystalline  lens  has  been,  though  very  rarely,  regenerated^ 
in  very  young  subjects,  after  its  entire  extraction. 

An  opacity  of  the  crystalline  lens,  or  its  dapsule,  or  both  at  the 
same  time,  constitutes  cataract. 

2.   The  Vitreous  Body. 

This  body  (Figs.  426  and  431)  is  a  close  web  of  transparent 
fibres,  enveloping  a  transparent  fluid  in  its  meshes;  and  is  inclosed 
in  a  simple  membrane  (membrana  hyaloidea),  on  the  exterior  of 
which  vessels  are  distributed.  [Todd  and  Boivman.)  The  central 
artery  of  the  retina  passes  through  the  centre  of  the  vitreous  body, 
but  does  not  give  off  any  branches  to  it.  Its  nourishment  is  pro- 
bably in  part  sustained  by  the  plexiform  arrangement  of  vessels  ■ 
constituting  the  ciliary  processes.     (Fig.  430.) 

The  fluid  of  the  vitreous  humor  is  a  weak,  watery  solution  of 
salts  and  albumen. 

Daring  foetal  life,  this  body  is  supplied  with  vessels  in  its  inte- 
rior also. 

Use. — This  is  also  one  of  the  refracting  humors  of  the  eye. 


The  eyeball  is  covered  anteriorly  by  the  conjunctiva,  which  is 
essentially  a  mucous  membrane;  though  the  portion  in  front  of  the 
cornea  is  merely  a  compound  scaly  epithelium,  without  a  corium. 
This  also  continues  over  the  sclerotica,  where  there  is  a  pale,  thin 
corium,  without  any  papilliB,  and  attached  to  the  sclerotic  by  a 
loose  and  abundant  areolar  tissue  containing  fat-cells.     The  mem- 


604  THE   TISSUES. 

brane  is  reflected  from  the  sclerotica  above  and  below,  and  lines 
the  lids.  The  latter  also  have  a  compound  scaly  epithelium.  Pa- 
pilla, occur  on  the  palpebral  conjunctiva,  especially  towards  the 
line  of  reflection,  where  they  are  y^^  of  an  inch  long.  At  the 
line  of  reflection  they  are  sometimes  even  ^^  of  an  inch.  (Krause.) 
Their  enlargement  constitutes  the  granular  h'd,  so  called ;  the  lower 
lid  being  most  frequently  affected,  since  they  are  most  abundant 
there. 

The  eyelids  consist  of — \st^  the  mucous  membrane  just  described; 
2dhj^  the  fibres  of  the  levator  palpebrge  superioris,  and  the  orbicu- 
laris palpebrarum;  and,  2>dly^  the  skin,  only  gV  to  ^^  of  an  inch 
thick ;  all  these  elements  being  connected  together  by  a  lax  con- 
nective tissue.  The  skin  is  furnished  throughout  with  minute 
sweat-glands  {^Is  to  y^^  of  an  inch),  and  generally  with  minute 
hairs  and  sebaceous  glands.  The  free  borders  of  the  lids  are 
bounded  by  the  tarsi^  improperly  termed  tarsal  cartilages.  They 
consist  merely  of  fasciculi  of  white  fibrous  tissue,  though  occasion- 
ally containing  a  few  minute  cartilage-cells.  Into  their  free  edges 
the  cilia  (eyelashes)  are  inserted,  immediately  in  relation  with  the 
Meibomian  glands.     (Fig.  133.) 

But  for  a  full  description  of  the  remaining  appendages  of  the 
eye  (the  muscles  and  the  lachrymal  passages,  &c.)  the  works  on 
descriptive  anatomy  may  be  consulted,  since  they  present  no  pecu- 
liar histological  elements.  For  the  very  numerous  pathological 
conditions  to  which  this  organ  is  liable,  reference  must  be  had  to 
the  special  treatises  on  this  subject. 


INDEX. 


Absorption  by  cells,  128 

Acarus  folliculorum,  226 

Accessory  organs  of  skin ;  sebaceous  and 
sweat  glands,  486-92 

Acid,  carbonic,  44;  hippuric,  64  ;  lactic,  60  ; 
pneumic,  67;  uric,  61 

Acne,  135 

Acoustic  nerve,  453-54 

Adhesions,  497. 

Adipose  cells,  286 

Adipose  tissue,  295-312  ;  fat-cells,  peculiari- 
ties, 296  ;  intercellular  areolar  tissue,  296  ; 
vessels,  297  ;  crystals  in  cells,  297  ;  pecu- 
liarities in  lower  animals,  298  ;  chemical 
composition,  298;  distribution,  299;  pe- 
culiarities in  distribution,  300  ;  circum- 
stances modifying  its  amount,  302  ;  distri- 
bution in  lower  animals,  303  ;  uses  of  fat, 
304;  development,  305;  growth,  306; 
pathological  states,  306  ;  stearosis,  or  fatty 
degeneration,  309-12 

Aerating  process,  its  object,  44 

Age,  eiFects  on  composition  of  blood,  173 

Air-cavities  in  hairs,  254 

Air-cells,  577  ;  hypertrophy  of,  581 ;  oblitera- 
tion of,  581 

Air-passages,  572  ;  function  of,  580 

Albinoes,  132-3 

Albumen,  84—7;  physical  and  chemical  pro- 
perties, 84 ;  occiirrence,  origin,  uses,  85, 
120  ;  remarks,  86  ;  pathological  relations, 
87  ;  albuminuria  in  various  states,  87  ;  al- 
bumen in  various  secretions,  87  ;  antidote 
to  corrosive  sublimate,  86 ;  the  pabulum 
of  the  tissues,  86,  120,  158 ;  amount  in 
blood-serum,  153  ;  uses,  158  ;  in  what  dis- 
eases increased,  179  ;  in  what  diminished, 
179 

Albuminuria  in  various  pathological  states, 
87,  220  ;  the  blood  in,  178 

Albuminose,  87  ;  uses,  88  ;  results  from  diges- 
tion, 200 

Alimentary  canal  and  appendages,  514-41 ; 
oral  cavity,  514-22;  pharynx,  522;  ceso- 
phagus,  522  ;  stomach,  523-26  ;  duodenum, 
527;  jejunum  and  ileum,  527-31;  large 
intestine,  531-2;  liver,  632-40;  pancreas, 
540 

Alternating  calculus,  66 


Ammonia  free  in  the  blood,  95,  iiote;  hydro 
chlorate  of,  51;  carbonate  in  blood  in  dis 
ease,  155 

Ammonio-magnesian  phosphate,  56 ;  forms 
of  its  crystals,  57 

Amphiarthrosis,  346 

AnEemia,  the  blood  in,  178- 

Analysis,  histological,  of  body,  32  ;  chemical 
of  liquor  sanguinis,  152;  do.  of  blood-cor 
puscles,  163  ;  dry  blood,  167  ;  bone,  332-5 
diseased  do.,  334;  nervous  centres,  473 
muscular  fibre,  396  ;  milk,  204  ;  urine,  217 
dentine,  368 ;  enamel,  372 ;  cementum, 
373;  liver,  539;  thyroid  gland,  589 

Anasarca,  294 

Anastomosing  fibres  of  heart,  394 

Aorta  of  whale,  272 

Apolar  nerve-cells,  436 

Aponeurosis,  structure  of,  278 

Apoplexy  of  lungs,  582 

Appendages  of  alimentary  canal,  532—40  ;  of 
skin,  249-55 

Arachnoid,  469 

Arcus  senilis,  282 

Areola  darker  in  pregnancy,  136  ;  its  struc- 
ture, 570 

Areolae  of  areolar  tissue,  285  ;  their  contents, 
286 

Areolar  tissue,  284-95  ;  its  two  kinds  of  fibres, 
its  areolae,  285 ;  their  contents ;  emphy- 
sema, 286  ;  chemical  composition  ;  proper- 
ties ;  vessels,  287;  uses;  distribution,  288; 
peculiarities,  289  ;  subcutaneous  areolar 
tissue,  289-90:  development,  291-3;  re- 
generation, 293;  pathological  states  of, 
294 ;  new  formations,  295 

Areolitis,  294 

Arrectores  pili,  267,  477 

Arterial  blood  compared  with  venous,  174 

Arteries,  500-504;  external  tunic,  500;  mid- 
dle do.,  501;  inner  do.,  502;  vasa  vaso- 
rum,  503;  development  of  arteries,  511; 
arteries  of  bone,  337 

Articular  cartilages,  342— i ;  peculiarities; 
the  bone  under  them,  343  ;  pathological 
states,  344 

Ascites,  496 

Ass,  milK  of,  206 

Atelectasis  pulmonum,  582 

Atheroma,  312;  of  arteries.  513 

Atrophy  of  cells,  130  ;  of  white  fibrous  tissue. 


606 


INDEX. 


283;  areolar  tissue,  293;  adipose  tissue, 
306  ;  cartilage,  320  ;  bone,  365  ;  smooth 
muscular  fibre,  392;  striated  do.  do.,  406; 
tendons  and  aponeuroses,  422 ;  mucous 
membrane,  495 

Axile-corpu.scles,  483 

Axis-fibre,  425 


B 


Bat,  hair  of,  257  ^ 

Beard,  uses  of,  265 

Belly  of  muscles,  410 

Bile,  from  fat  of  the  blood,  77;  properties, 
210  ;  amount,  origin,  211 ;  uses,  212  ;  patho- 
logical states,  213 

Biliary  calculi,  213 

Bladder,  541-2 

Blastema,  120,  7Wte 

Blood,  151-70  ;  properties,  specific  gravity, 
coagulation,  151;  liquor  sanguinis,  analy- 
sis of,  152  ;  amount  of  fibrine,  water,  and 
albumen  in,  153;  blood  serum,  153;  fats 
in  serum;  glucose;  mineral  constituents, 
155  ;  origin  and  uses  of  each  constituent, 
156-59  ;  uses  of  fibrine  ;  albumen  the  pabu- 
lum of  the  tissues ;  colorless  corpuscles, 
159-61;  colored  do.,  162-72;  quantity  of 
blood,  172  ;  composition  in  various  physio- 
logical states,  173  ;  normal  differences  in 
different  vessels,  174  ;  changes  in  various 
diseases,  176  ;  the  life  of  the  blood,  170 

Blood-corpuscles,  colorless  {see  Colorless  cor- 
puscles, Ac.)  ;  do.  colored  {see  Colored  cor- 
puscles of  the  blood) 

Blood-vascular  glands,  582-93  ;  the  spleen, 
58.3-7 ;  thyroid  gland,  688-90 ;  thymus 
gland,  590-3;  supra-renal  do.,  592-3 

Bloodvessels  of  arteries,  503;  of  bones,  337; 
of  muscles,  413  ;  of  nerves,  438  ;  nervous 
centres,  472;  of  membranes  of  brain,  Ac, 
470  ;  of  .skin,  482 

Blubber  of  seal  and  whale,  303 

Bone,  structure  of,  336-42 ;  vessels,  337 ; 
nerves,  338 ;  marrow,  339 ;  periosteum, 
341 ;  articular  cartilage,  342-4  ;  fibro-car- 
tilages  of  circumference,  342 ;  synovial 
membranes,  344  ;  inter-articular  fibro-car- 
tilages  and  ligaments,  345-6  ;  connection 
of  tendons  and  ligaments  with  bones,  346  ; 
joints,  their  structure,  346-7  ;  strength  of 
bones,  348 ;  their  uses,  348-9 ;  develop- 
ment of  bones,  350-60  ;  remarks  on,  360-2  ; 
growth  of  bone,  363  ;  reparation,  363-5  ; 
pathological  conditions,  365-7 

Bone  tissue  (see  osseous  tissue,  321-26) 

Bronchi,  575 

Bronchial  arteries,  576;  dilatation,  681 

Bronchocele,  589 

Brunner's  glands,  629 

Buffy  coat  of  blood,  93,  165 

Butter,  contains  no  stearine,  76 

Bursse  mucosa;,  418 ;  do.  subcutaneous,  486 


C. 

Calcification,  .367 
Calcium,  36  ;  fluoride  of,  51 


Calculi,  biliary,  213 ;  vesical,  22.3-4 

Cancellated  bone  structure,  326-8  ;  develop- 
ment, 351-5 

Cancellus,  326  ;  contents  of,  328 ;  develop- 
ment, 355 

Cancer,  varieties  of,  137  ;  cancer  of  bone,  366 
i  Cancer  cells,  138  143  ;  nuclei,  138  ;  nucleoli: 
6  forms  of  cells,  139  ;  polygonal  cells,  139 ; 
caudated,  fusiform,  140  ;  concentric  ;  mo- 
ther cells,  agglomerated  nuclei,  141  ;  ele- 
ments mistakable  for  cancer  cells  and 
nuclei ;  fusiform  corpuscles  and  fibro-plastic 
tissue,  fibro-plastic  cells,  and  free  nuclei, 
cells  of  enchondroma,  tubercle-corpuscles, 
epithelial  cells,  142  ;  the  microscope  in  the 
diagnosis  of  cancer,  144 ;  epithelial  can- 
cer, 247 

Capillaries,  504  ;  structure,  505  ;  plexuses  of, 
505  ;  development,  512  ;  vasa  serosa,  506  ; 
capillaries  of  muscles,  414 

Cajiillary  network  of  liver,  539  ;  do.  plexuses, 
505 ;  do.  plexus  of  lungs,  579 ;  capillary 
lymphatics,  509 

Caput  gallinaginis,  553 

Carbonate  of  ammonia,  in  blood,  155  ;  do. 
lime,  where  found,  its  form  in  urine,  its 
source,  52 ;  do.  and  bicarbonate  of  po- 
tassa,  53;  do.  magnesia,  58  ;  do.  of  soda, 
53 

Carbonic  acid,  where  found  free  in  the  body, 
44  ;  its  amount ;  is  dissolved  in  the  blood  ; 
how  formed,  44  ;  exists  in  all  animal  fluids, 
44  ;  note  ;   in  sweat,  230 

Carcinoma,  the  blood  in,  178 

Caries,  of  cartilage,  326  ;  of  bone,  335 ;  of 
teeth,  383 

Cartilage,  31.3-20 ;  simple  do.,  compound, 
313;  fibro-cartilage,  reticular  do.,  314; 
hyaline  cartilage,  315  ;  perichondrium, 
chemical  composition,  315  ;  properties  and 
uses,  316;  development,  growth,  317; 
articular  cartilages,  318 ;  pathological 
states  of  cartilage,  319-20 

Cartilage  cells,  multiplication  of,  126 

Cartilageine,  peculiar  to  cartilage  and  fibro- 
cartilage,  99  ;  relation  to  chondrine,  uses, 
100 

Cartilaginous  skeleton,  350 

Caseine,  properties,  88  ;  origin  and  uses,  89 

Castoreum,  227 

Casts  in  uriniferous  tubes,  550 

Cataract,  603 

Cells,  114-30;  cell  wall,  114;  contained 
fluid,  115;  nucleus,  116;  pathological  de- 
velopments of  nuclei,  117-19;  tubercle- 
corpuscles,  118;  glomerulus,  119;  the 
nucleolus,  119;  cell-development,  122-6; 
free  do.,  120-2;  endogenous,  122-5;  do. 
by  multiplication,  126;  growth  of  cells, 
functions,  127-8;   pathological  states,  129 

Cellular  tissue  (see  areolar  tissue),  284 

Cemcntum,  372;  analysis  of,  373  ;  changes 
in  the  aged,  374  ;  development  of,  381 

Cerebellum,  462-4  ;  its  convolutions,  463  ; 
its  crura,  464 

Cerebral  hemispheres,  465-8  ;  their  white 
substance,  465  ;  gray  matter,  466  ;  nerve- 
fibres,  407 

Cerebrum,   its  ganglia,   464-6;    optic  lobes 


INDEX. 


60 


and  thalami,  and  corpus  etriatum,  4G4 ; 
pineal,  and  pituitary  body,  405 

Cerumen,  228 

Ceruniinous  glands,  492 

Cervix  uteri,  602 

Chemical  formulao  (refer  to  each  particular 
compound)  ;  do  ,  composition  (refer  to 
each  partii'ular  tissue) 

Chloride  of  sodium  ;  in  every  human  solid 
and  fluid;  quantity;  forms  of  crystals, 
49  ;  its  uses  in  the  blood,  and  in  food  ;  how 
leaves  the  body  ;  its  crystals  in  urine,  50  ; 
most  abundant  in  cartilage,  .'ilO 

Chloride  of  potassium  ;  where  found  in  the 
body  ;  amount  in  muscle  and  in  milk;  may 
be  formed  in  the  body,  50 

Chlorine,  30 

Chlorophyl,  135 

Chlorosis,  the  blood  in,  178 

Cholesterine,  75  ;  how  formed,  76 

Cholera,  the  blood  in,  177 

Cholesteatoma,  309 

Chololithi,  213 

Chondrine,  not  an  immediate  principle,  83, 
99 

Chordne  vocales,  573  ;  do.  tendineao,  499 

Chorea,  403 

Choroid  coat  of  the  eye,  597-8 

Chyle,  properties ;  li((uor  ch3ii,  149  ;  do. 
corpuscles,  145,  150  ;  quantity  of  chyle  ; 
origin,  150  ;   uses,  151 

Cilia,  243-4 

Ciliary  motion,  244  and  7iotc ;  do.  ligament, 
595  ;  do.  processes,  599 

Ciliated  epithelium,  143,  246 

Cirrhosis  of  liver,  283,  540 

Clavus,  247,  493 

Cleavage  fibres,  113;  do.  masses,  124 

Clitoris,  559,  569 

Coagulation,  81,  93;  how  modified  by  va- 
rious agents,  94  ;  coagulation  of  blood,  151 

Cochlear  nerve,  454 

Cod-liver  oil,  79,  170,  7iote 

Collagenous  tissue  {see  White  fibrous  tissue) 
278-84 

Colloid,  137 

Color,  of  hair,  134,  255  ;  of  eyes,  1.34  ;  of 
blood-corpuscles,  how  modified,  166 ;  of 
muscular  fibre,  397 

Colored  blood-corpuscles,  original  develop- 
ment, 126,  169;  description,  162;  size  in 
mau  and  lower  animals,  162 ;  analysis, 
163  ;  gases  in,  164  ;  iron,  164,  note;  fibrin- 
ous flakes,  165  ;  tendency  to  sink,  165  ; 
color,  how  modified,  106;  number,  167; 
development,  169-70  ;  functions,  171  ;  me- 
tamorphoses, 172;  amount  in  lower  ani- 
mals, 174;  variations  in  various  diseases, 
179 

Colorless  blood-corpuscles,  145,  150  ;  deve- 
lopment, 166  ;  use.-i,  100  ;  stearosis  of,  162  ; 
increased  in  what  diseases,  179 

Colostrum,  203 

Columntv;  carnetc,  499 

Columns  of  Bertini,  545 

Columns  of  spinal  cord,  456  ;  of  medulla  ob- 
longata, 401 

Compact  bone  structure,  328-31  ;  develop- 
ment, 356-8 


Composition  of  the  blood  ;  variation."?  in  dif- 
ferent healthy  conditions,  173  ;  do.  in  dif- 
ferent vcsseLs,  174  ;  in  arteries,  portal  vein, 
174;  hepatic  vein,  splenic  vein,  placental 
ves.sels,  175;  menstrual  blood,  176;  in  in- 
flammation, fever,  cholera,  and  dysentery, 
177;  acute  exanthemata,  puerperal  fever, 
albuminuria,  pleUiora,  hydrajmiii,  anscmia, 
chlorosis,  leucicinia,  pyaemia,  carcinoma, 
diabetes,  etherization,  178 

Concretions,  in  muscle,  407 

Condyloma,  247 

Connective  tissue,  274,  284,  288;  do.  do. 
cells,  189 

Contents  of  cells,  114,  127;  changes  in,  128; 
do.  of  blood-corpuscles,  163-4 ;  do.  of 
nerve-cells,  435 

Contractile  fibre-cells,  384 

Contractility,  401 

Contraction,  by  cells,  129 ;  do.  muscular, 
changes  during,  407 

Conjunctiva,  603 

Convolutions  of  cerebellum,  463 

Cornea,  its  structure,  280-2  ;  arcus  senilis, 
282 

Corpora  lutea,  567;  do.  quadrigemina,  464; 
do.  olivaria,  pyramidalia  and  restiformia,  , 
461 ;   do.  striata,  464 

Corpulence,  its  remedy,  77,  301;  cases  of. 
300 

Corpus  cavernosum,  550-1;  do.  Ilighmorian- 
um,  554 ;  do.  spongiosum,  550 

Cowper's  glands,  551 

Cow's  milk,  analj'sis  of,  206  ;  quantity  of, 
205,  7wte 

Creatine,  its  crystals,  origin,  67 

Creatinine,  68 

Crura  cerebelli,  464 

Crystalline,  not  identical  with  globuline,  97 

Crystalline  lens,  600-603  ;  its  tubes,  601 ;  its 
capsule,  602  ;  cataract,  602 

Cuticle  of  hair,  255  ;  of  skin,  479 

Cutaneous  secretions,  225-31  :  sebaceous  do., 
225-28  ;  perspiration,  229-31 

Cutis  anserina,  207,  493 

Cystic  duct,  536 

Cystine,  69 

Cysts,  in  the  kidney,  549 

Cytoblast,  120,  note 

Cytoblastema,  120,  note 

Cytogeny,  120-0 

Cytoid  corpusgles,  144-5 ;  development  of, 
146  ;  uses,  147 

Cytology,  114-30 


D 


Decidua  vera,  and  ri^fl^xa,  565 

Dentinal  globules,  370 

Dentine,  367-70 ;  intertubular  ."sub.stance, 
368  ;  analysis  of,  368;  the  tubuli,  369 

Dental  tissues,  367 

Development  of  cells,  122,  126  ;  of  pigment- 
cells,  35;  of  colorless  bio  )d-eorpuscles, 
146,  160;  of  colored  ilo.  do.,  l()8-70  ;  oi 
pus-corpuscles,  191 :  mucus-corpuscles,  197; 
milk  globules,  205  ;  spermatozoids,  209  ; 
epithelium,   244;    nails,   252;    hair,   262; 


608 


IXDEX. 


elastic  tissue,  272-4;  wliite  fibrous  tissue, 
282-3:  areolar  tissue,  291-3;  adipose  tis- 
sue, 305  ;  cartilage,  317  ;  bone,  350-62 

Development  of  kidney,  548 

of  membranes,  421 

of  nerve-cells,  437 

'  of  sebaceous  glands,  488 

^  of  smooth  muscular  fibres,  391 

of  sweat  glands,  491 

of  tendons,  421 

of  teeth,  370-82 

of  vascular  system,  511-13 

of  striated  muscular  fibre,  399 

Diabetic  sugar,  70 

Diabetes,  glucose  in  secretions,  70  ;  state  of 
blood  in,  178 

Diapbysis,  336,  note 

Diatheses,  346 

Digestion,  effects  on  composition  of  blood, 
173  ;  part  effected  by  gastric  fluid,  200  ; 
do.  do.  intestinal  fluid,  201  ;  do.  do.  the 
saliva,  210 

Distribution  of  smooth  muscular  fibres,  587- 
88  ;  do.  in  lower  animals,  389  ;  of  striated 
muscular  fibres,  397;  do.  in  lower  animals, 
398 

of  nerve-fibres,  429 

of  nerve-cells,  435 

Dropsy,  of  cells,  130 

Ductus  communis  choledochus,  536 

Ductless  glands,  582-93 

Dura  mater,  470 

Duverney's  glands,  559 

Dysentery,  the  blood  in,  177 


Ear,  its  structure,  594-0 

Ecchymosis,  294 

Eczema,  493 

Efficient  force  of  muscle,  420 

Ejaculatory  ducts,  553 

Ejaculatio  seminis,  558 

Elasticine,  peculiar  to  elastic  tissue  ;  uses,  100 

Elastic  tissue,    268 — 275   [see  Yellow  fibrous 

tis.sue) 
Elasticity  of  muscles,  419 
Elements,   chemical,   in    human    body,    35; 

sulphur,  phosphorus,  calcium,  magne.-iuin, 

sodium,  potassium,  chlorine,  3C ;  fluorine, 

silicura,  iron,  manganese.  37. 

necessary  in  the  food,  37 

Elephantiasis  Graecorum,  404 
Emaciation,  307 
Emaciated  muscles,  407 
Emphy.sema,  286,  294 

of  lungs,  581 

Empyema,  496 

artificially  produced,  94 

most  common  when,  188 

Enamel,  370-2 

analysis  of,  372 

development  of,  380 

Encephaloid,  137 

its  cells,  125 

Encephalic  nerves,  446-54 

their  endowments,  440-7 


Encej)halon,  455 


Enchondroma,  319 

Encysted  tumors,  308 

Endocardium,  499 

Endogenous  cell-development,  122-25 

Endosmosis,  defined,  110,  ttote 

Endosteum,  340 

Ependyma  ventriculorum,  469 

Ephelis  hepatica,  137 

Epididymis,  556 

Epiglottis,  573-4 

Epilepsy,  463 

Epiphysis,  335,  note 

Epithelium,    234-49 ;     definition,    235 ;    its 
thickness,   size   of    cells,  236 ;    varieties 
simple    scaly,    238-9 ;    peculiarities,   238 
compound  scaly,   240 ;   peculiarities,  240 
epithelial  plates,   241 ;    in  lower  animals 
simple  conoidal  epithelium,  241 ;  distribu 
tion,  242;    compound  conoidal   do.,  243 
ciliated  epithelium  ;  the  cilia,  243  ;  distri- 
bution,  244 ;    varieties  of  epithelium   are 
respected  by  disease,  244  ;  development  of 
epithelium,  244  ;  reparation  of,  245  ;  func- 
tions of,  245-46  ;  action  of  chemical  agents 
upon,  246  ;  pathological  conditions  of,  247- 
9  ;    warts,  corns,  condylomata,   epithelial 
cancer,    247 ;     new    formations    of,    248 ; 
oidium  albicans,  248 

Epithelial  cancer,  247 

Epithelium  of  skin,  development,  484 

Eiiithelioma,  247 

Epithelial  cells,  young,  143;  of  mouth,  143; 
no  peculiarity  of  form  and  contents,  at  first, 
235  ;  their  size,  236 

Etherization,  state  of  the  blood  in,  178 

Euplastic  and  cneoplastic  exudations,  186 

E.xantbemata,  493 

acute,  blood  in,  178 


Exosmosis,  defined,  110,  iiote 
Exostosis,  320-3 
of  teeth,  382 


Extractive  matters  of  liquor  sanguinis,  152  ; 
increased  in  what  diseases,  179 

Exudations,  distinguished  from  serous  .secre- 
tions and  transudations,  180-4  ;  definition, 

184  ;  not  always  due  to  inflammation,  184  ; 
differ  from  transudations  in  composition, 

185  ;  origin,  185  ;  uses,  186 ;  varieties, 
euplastic  and  cacoplastic,  186 ;  changes 
occurring  in,  186  ;  absorption,  organiza- 
tion, and  suppuration,  187  ;  organization 
of  exudation  modified  by  condition  of  the 
blood,  and  seat,  and  intensity,  of  inflam- 
mation, 188  ;  pus,  how  formed  in  exuda- 
tion, 189 

Exudation  cells,  188 

Exudation  corpu.scles,  118,  145  ;  relations  to 

pus  corpuscles,  188 
Eye,  597—004  ;  its  membranes,  594—600  ;  its 

humors,  600-3  ;  the  conjunctiva,  603 
Eyelids,  structure  of,  604 


F 


Facial  nerve,  447 

Fallopian  tubes  {see  Oviducts,  563) 

False  memlirane,  497 

Fascia),  417 


INDEX. 


609 


Fat  flrops,  or  jrlobule?,  where  found,  74,  78 

Fat  in  Mood,  iiniount,  152;  uses  of,  77;  do. 
in  milk,  Ac,  78;  do.  in  brain,  79,  473 

Fats,  saponifia))le  and  non-saponifiable,  77 

Fatty  degeneration,  74-78,  309-13 

Fatty  principles,  73-80 

Fenestrated  layer  of  vessels,  502 

Ferruginous  layer  of  cerebellum,  117 

Fevers,  the  blood  in,  177 

Fibres  of  Remak,  429,  445 

Fibre,  simple,  112-14 

Fibrilla;,  of  striated  fibres,  396 

Fibrillation  of  fibrine,  when  most  perfect, 
93-4 

Fibrinous  flakes,  165 

Fibrine,  89  ;  properties ;  appearance  of  co- 
agulum,  90 ;  is  not  oxydated  albumen  , 
possesses  vitalitj' ;  uses  ;  91  ;  its  metamor- 
phosis; its  coagulation,  92;  its  fibrillation  ; 
when  most  perfect ;  buffy  coat,  93 ;  not 
the  sole  plastic  element  of  the  blood,  95, 
156;  amount  in  the  blood,  162;  uses  there, 
158;  increased  in  what  diseases,  178;  di- 
minished in  do.  do.,  179 

Fibrous  cancer,  137 

Fibro-cartilages,  structure  of,  278,  314 

Fibro-cartilages  with  tendons,  419 

Fibro-cartilages  of  circumference,  342 

Fibro-plastic  cells,  fusiform  and  spherical, 
142 

Fifth  pair  of  nerves,  446 

Fissiparous  cell  development,  125 

Fluoride  of  calcium ;  amount  in  bones  and 
teeth  ;  its  source  unknown,  51 

Fluorine,  37 

Follicular  glands,  520,  529 

Formulae,  chemical;  refer  to  each  particular 
compound 

Fractures,  how  repaired,  364 

Freckles,  137 

Free  cell  development,  120-22  ;  pathological 
do.  do.  do.,  122 

Free  nuclei,  115,  117,  119 

Fontanelles,  360 

Functions  of  cells,  128  ;  primordial  cells,  pig- 
ment do.,  colorless  blood-corpuscles,  161  ; 
colored  do.  do.,  171 

Function  of  smooth  muscular  fibres,  39 ;  of 
striated  do.  do.,  401 


G. 


Gall-stones,  75 

Ganglia  of  sympathetic  nerves,  444;  of  cere- 
brum, 464 

Ganglion  cells,  439  ;  do.  of  sympathetic 
nerves,  444 

Ganglion  fibres,  439 ;  do.  of  sympathetic 
nerves,  445 

Ganglionic  nerves,  444  ;  structure  of,  444-6  ; 
copimunicating  branches,  444 ;  their  gan- 
glia, 444 ;  ganglion  cells  and  ganglion 
fibres,  445  ;  their  distribution,  445 

Gases,  in  blood,  164 

Gastric  fluid, "  characters  and  composition, 
193;  quantity,  origin,  199  ;  uses,  200 

Gastric  peptic  glands,  199  ;  do.  favuli,  199 

Gelatinous  nerve  fibres,  429 


Germinal   eminence,    565  ;  do.    vesicJe,   do. 

spot,  567 
Germinal  spot,  116  ;  do.  vesicle,  116 
Giraffe,  ligamentum  nuchsc  of,  269,  272 
Glands,  various  forms  of,  476 
Glands  of  oral  cavity,  519 — 522 
follicular,  520 


Glandula)  solitaria3,  530  ;  of  colon,  531 
agminatae,  529 


Glandular  secretions,  202  to  224  ;  milk,  202 
to  207  ;  semen,  207  to  209  ;  saliva,  209  to 
210;  bile,  210  to  213;  pancreatic  fluid, 
213  ;  urine,  214  to  224  ;  lachrymal  fluid, 
225 

Glandular  epithelium,  237 

Globulinc,  properties,  origin,  uses,  96 

Glomeruli,  78,  119 

Glossopharyngeal  nerve,  446 

Glucose,  70 

Glutin,  not  an  immediate  principle,  83,  98 

Glycerine,  76 

Goat's  milk,  206 

Graafian  follicle,  565 

Granules  in  cells,  115  ;  in  ova,  116  ;  and  in 
spermatophori,  116,  208 

Grape  sugar,  70 

Gray  commissure,  456   - 

Growth  of  bones,  363  ;  action  of  madder, 
363 

of  corium  of  skin,    485  ;    sebaceous 


glands,  489 

of  teeth,  382 

of  cells,  127  ;   epithelium,  245  ;  nails. 


39 


251  ;  hair,  266  ;  elastic  tissue,  274;  white 
fibrous  tissue,  283  ;  adipose  do.  306  ;  car- 
tilage, 317 ;  of  other  tissues,  {see  each 
particular  tissue) 

Gubernaculum  dentis,  376 

Gums,  structure  of,  375 


H 


Haematine,  only  in  red  blood-corpuscles  ;  pro- 
portion, 101  and  163;  iron  combined  with 
it ;  proportion  ;  origin  ;  uses  ;  transforma- 
tion, 102  ;  crystals  from  blood  ;  relations 
to  haematine,  103 

Hfematoidine  ;  occurrence,  origin,  102 

Haematosis,  540 

Hsemato-globuline,  96,  163 

Hairs,  253  to  268  ;  the  shaft ;  its  fibrous  sub- 
stance, 253  ;  plates  of  latter  ;  pigment  gra- 
nules ;  cavities  filled  with  air,  254  ;  color 
of  fibrous  substance  ;  the  cuticle;  its  plates; 
the  medulla,  255  ;  hair  sacs,  root-sheath, 
257;  papilla,  250;  chem.  composition  and 
physical  properties  of  hair,  259  ;  distribu- 
tion and  size,  260 ;  development,  262  :  fall- 
ing out,  264  ;  uses  and  physiological  rela- 
tions, 265  to  267  ;  hair  dyes,  267;  patho- 
logical states,  267  ;  alopecia,  porrigo,  plica 
Polonica,  268 

Haptogen  membrane,  115,  note 

Haversian  canals,  324  ;  do.  spaces,  325 

Heart,  498-9  ;  pericardium,  498  ;  endocar- 
dium, 499  ;  the  valves,  499  ;  vessels,  499  ; 
lymphatics,  500  ;  nerves,  500 

Heiicine  arteries,  552 


m. 


INDEX. 


Hemispheres  of  cerebrum,  465 

Hepatic  arteries,  539 

Hepatic  cells,  533  ;  do.  ducts,  53-1-5  ;  rela- 
tions to  the  cells,  536 

Hepatization,  red  and  gray,  188,  581 

Hepatic  sugar,  70 

Hepatic  vein,  peculiarities  of  its  blood,  175 

Herpes,  493 

Hippuric  acid  ;  in  urine  ;  form  of  crystals  ; 
hippurate  of  lime,  soda,  and  potassa,  64 

Histology  ;  definition  ;  subdivisions,  105 

Histological  elements,  82  ;  homogeneous  sub- 
stance, 107-9  ;  simple  membrane,  109-11  j 
simple  fibre,  112 

Homogeneous  connective  tissue,  276 

Homogeneous  substance  ;  definition,  distri- 
bution, 107;  two  varieties;  origin,  func- 
tions, 108  ;  stearosis  of,  109 

Hottentot  women,  corpulence  of,  300 

Housemaid's  knee,  423 

Humors  of  the  eye,  600-3  ;  crystalline  lens, 
600-3  ;  vitreous  body,  603 

Hyaline  substance,  108;   do.,  cartilages,  314 

Hydrieraia,  the  blood  in,  178 

Hydrochloric  acid,  in  gastric  juice,  199 

Hydrochlorate  of  ammonia,  where  found  in 
the  body,  51 

Hj'drogen,  where  found  free  in  the  body,  43 

carburetted  and  sulphuretted,  formed 

in  disease,  44,  7iote 

■protoxide  (see  "Water). 

Hj'drocele,  496 

Hj'drops  pericardii,  496 

HyJrothorax,  495 

Hygrology,  145 

Hyperinosis,  178 

Hypertrophy  of  areolar  tissue,  293  ;  of  bones, 
365 

of  thyroid  gland,  589 

of  smooth  muscular  fibre,  391 

of  striated       "  "405 

Hypinosis,  179 

Hypoglossal  nerve,  447 


Immediate  principles ;  definition,  38  ;  classi- 
fication, 39—41 

of  mineral  origin,  42-7  ;  oxygen,  43  ; 

hydrogen,  43  ;  nitrogen,  and  carbonic  acid, 
44  ;  water,  45 

■  saline  ;  classification,  40  ;  are  usually 


dissolved  in  water;  uses;  ijhosphates  and 
carbonates  of  soda  replace  each  other  in 
food,  48;  observations  of  B.  Jones,  49 

of  organic  origin  ;    not  assimilable  ; 


quite  numerous  ;  contain  but  9  simple  ele- 
ments, 69  ;  classification,  40-1 ;  lactic  acid, 
60  ;  uric  acid,  61  to  64 ;  hippuric  do.,  64  ; 
oxalate  of  lime,  64 

•  fatty  ;  in  3  forms,  74  ;  fat  globules  ; 


origin,  74 ;  uses ;  formed  in  liver,  75  ; 
cholesterine,  75 ;  oleine,  margarine,  and 
stearine,  76  ;  uses  of  fatty  principles,  77 ; 
secretions  containing  fat,  78 ;  remarks  on 
cod-liver  oil,  70 

organic,  or  coagulable,   80   to    104; 


general  remarks,  80  to  83 ;  have  no  definite 


chemical  composition,  80  ;  those  naturally 
fluid,  83  to  95 ;  solid  and  demisolid,  96  to 
101  ;  coloring  substances,  101  to  104 

Inflammation,  composition  of  the  blood  in, 
176 

Infundibula  of  lungs,  577 

Inosite,  97,  fwte 

Interarticular  fibro-cartilages  and  ligaments, 
345-6 

Intestinal  fluid,  composition  and  characters, 
200  ;  quantity,  origin,  uses,  201 

Intrinsic  force  of  muscles,  420 

Involution  of  cells,  130 

Involution  of  muscular  fibres  of  uterus,  389 

Islets  of  liver,  532 

Iris,  its  structure,  599  ;  muscular  fibres,  dila- 
tor and  sphincter  pupillae,  599 

Iron,  37,  102,  164 

Iron  with  hajmatine,  102;  in  blood-cells,  164, 
'note 

Isolated  cells,  131,  144;  pigment  cells,  131- 
7  ;  cancer  cells,  137 — 144 


Jacobson's  membrane,  452 

Jaundice,  540 

Joints,  their  structure,  340 


Keloid  tumors,  283 

Keratine,  100,  283 

Kidney,  542-48  ;  tubuli  uriniferi  and  eon- 
torti,  543  ;  number  of  latter,  543  ;  vascular 
portion,  Malpighian  bodies,  545  ;  vessels 
and  nerves,  547 ;  chemical  composition, 
548;  function  and  development,  548; 
pathological  conditions,  549 

Kiesteine,  not  allied  to  caseine,  89 


Lachrymal  fluid,  225 

Lactate  of  soda,  potassa,  and  lime,  61 

Lacteal     gland,    fabricates    sugar,    72;     its 

structure,   569-71 ;   structure  in  new-born 

child,  571 
Lacteals,  528 
Lactic  acid,  60  ;  lactates  of  soda,  potassa  and 

lime,  61;  in  gastric  juice,  199;  in  urine, 

218 
Lactine,  72 
Lactose,  72 
Lacunas  and  pores  of  bone,   323,  328,  330 ; 

development  of,  354 
Lambert,  Daniel,  his  corpulence,  300 
Lamellse  of  bone,  fundamental,  328;  special, 

329 
Lanugo,  260  _ 

Large  intestine,  structure,  531-2 
Larynx,  its  structure,  673 
Leucicmia,  KiO-l ;  the  blood  in,  175 
Lieberkiihn's  glands,  528,  531 
Ligaments,  structure  of,  278  ;  do.  of  tendons, 

418 


INJJEX. 


611 


Lime,  carbonate  of,  51 ;  oxalate,  64 ;  phos- 
phate, 54  ;  sulphate,  53 

Lipoma,  308 

Lipyl,  oxide  of,  76 

Liquor  sanguinis,  analysis,  152  ;  origin,  153  ; 
uses,  155 

Littre's  glands,  551 

Liver,  fabricates  sugar,  71  ;  its  structure, 
632-40;  Glisson's  capsule,  hepatic  cells, 
533;  ducts,  534—6;  their  sacculi,  537; 
capillary  network,  539  ;  composition  of 
liver,  540 ;  function  and  pathological 
states,  540 

Lobular  passages,  576-7 

Lobults  of  liver,  533;  do.  of  lungs,  577 

Loose  cartilages  in  joints,  319 

Lungs,  575-80  ;  pleura  ;  the  bronchi,  575  ; 
pulmonary  arteries,  576  ;  bronchial  do., 
576  ;  nerves  of  lung,  576  ;  lobules  of  lung, 
577;  terminal  air  tubes,  577;  air  cells, 
577 ;  infundibula,  lobular  passages,  577  ; 
plexus  of  capillaries,  579 ;  function  of 
lungs,  580  ;  development,  680  ;  pathologi- 
cal states  of,  581 

Lupus  exedens,  284 

Lymph,  147-8  ;   lymph  corpuscles,  148 

Lymphatic  vessels,  509  ;  do.  glands,  510 ; 
development,  513 


M 


Madder,  action  on  bones,  363 

Magnesia,   phosphate  of,  55  ;  carbonate,  58 

Magnesium,  36 

Malpighian  bodies  of  kidney,  645  ;  do.  of 
spleen,  585-6  ;  do.  layer  of  skin,  thickness, 
481 

Mammary  gland  (see  Lacteal  gland),  569 

Manganese,  37 

Mares'  milk,  206 

Margaric  acid,  crystals  in  fat-cells,  295 

Margarine,  76 

Marrow,  of  bones,  339  ;  two  varieties,  struc- 
ture, 340 

Medulla,  of  hair,  256 ;  of  bone,  339  ;  of 
nerve-fibres,  426  ;  do.  oblongata,  and  pons 
Varolii,  460-2 

Medullary  cavity  of  bones,  uses,  349 

Meibomian  glands,  487;   do.  secretion,  228 

Melanine,  104 

Melanotic  cancer,  138 

Membrana  granulosa,  239;  do.  hyaloidea, 
603  ;  praeformativa,  379 

Membrane,  simple,  109 

Membranes,  the,  473-97;  skin,  476-86; 
mucous  membranes,  494-6  ;  serous  mem- 
branes, 496  ;  false  membranes,  497  ;  sy- 
novial membranes,  344 

of  the  eye,  594—600  ;  sclerotic,  597  ; 

choroid,     597-8 ;    cornea,     280 ;     retina, 
450-2 

-of  nervouscentres,  468-75;  pia mater. 


468  ;  arachnoid,  469  ;  ependyma  of  ven- 
tricles, 469  ;  dura  mater,  470  ;  nerves  of 
the  membranes,  471 

Menstruation,  changes  in  uterus  during,  664 

Menstrual  fluid,  176 

Microscope  in  diagnosis  of  cancer,  144 


Miliaria,  493 
Milium,  494 
Milk,  202-6  ;  do.  of  lower  animals,  206 

globules,  115,  203 

sugar,  72 


Milk-teeth,  time  of  eruption,  381 

Minerals  necessary  in  food,  37 

Moles,  137 

Mother-cells,  141 

Mulberry  calculus,  66 

Multiplication  of  cells  by  division,  126 

Mummy,  weight  of,  32 

Mucosine,  84 

Mucous  membranes,  494-96 ;  pathological 
states,  495-6  ;  have  no  specific  character, 
195 

Mucus,  198-200  ;  quantity,  197  ;  uses,  198  ; 
varieties;  and  synovia,  198;  gastric  fluid, 
198-200;  intestinal  fluid,  200-2 

corpuscles,  146  ;  not  peculiar  to  mu- 
cus, 196 

Muscles,  structure,  408-22 ;  aponeuroses, 
tendons,  409  ;  belly  of  muscles,  its  struc- 
ture, 410  ;  connection  of  tendons  with  it, 
411  ;  do.  do.  do.  with  the  bones,  412-13  ; 
vessels  of  muscles,  413  ;  lymphatics  of  do., 
414;  nerves  of  do.,  414;  physical  proper- 
ties, 419  ;  intrinsic  and  efiective  force,  420  ; 
sensibility,  421  ;  development,  421 

Muscular  envelops,  417;  do.  fluid,  67,  97, 
386,  396 

tissue,  384—408;  no7i-stri'ated vnnscular 


tissue,  384 ;  its  vessels,  386  ;  chemical 
composition,  muscular  fluid,  386  ;  distribu- 
tion, 387-8;  do,  in  lower  animals,  389; 
those  of  uterus,  388  ;  function,  390  ;  de- 
velopment, 391  ;  pathological  conditions, 
391;  striated  muscular  tissue,  391-408 

Musculine,  97  ;  its  nourishing  properties  di- 
minished by  boiling  ;  its  transformations, 
98  ;  its  muscular  fibres,  384-96 

Myolemma,  393-6 

Myoline,  394 


N 


Nails,  249-253  ;  bed  of  nail,  249  ;  its  wall, 
body,  and  root;  lunula;  two  layers  of  nail, 
250  ;  structure,  growth,  natural  length, 
251;  development;  are  imperfectly  rege- 
nerated, uses,  252  ;  pathological  states  of 
nails,  252  ;  in  phthisis  and  cyanosis,  253 

Nasmyth's  membrane,  371 

Necrosis,  366 

of  cartilage,  320-5 

of  teeth,  383 


Negro,  cuticle  of,  133 

nearly  white  at  birth,  135,  485 


Nerve  cells,  434-37 ;  various  forms,  434 ; 
contents,  435  ;  distribution,  physical  pro- 
perties, 435  ;  functions,  435  ;  development, 
437  ;  pathological  states,  437 

Nerve  fibres,  coarse  and  fine,  423,  427  ;  de- 
velopment of,  431 ;  function,  430 ;  pale 
nerve  fibres,  428 

Nerves  of  heart,  500 

of  kidney,  548 

of  muscles,  415-16  ;  do.  in  lower  ani- 


mals, 416 


612 


INDEX. 


Nerves  of  pin-mater  and  dura-mater,  471 

of  skin,  483 

of  teeth,  375 

of  the  bones,  338;  of  short  do.,  flat 

do.,  339 

■  structure   of,    438-54 ;    perineurium, 


483  ;  bloodvessels,  483 
■  of  vessels,  503 


Nervous  centres,  structure  of,  455-72 ;  the 
spinal  cord,  456-60  ;  the  encephalon,  460- 
75  ;  medulla  oblongata,  400-2  ;  the  cere- 
bellum, 402  ;  ganglia  of  cerebrum,  464-5  ; 
cerebral  hemispheres,  465-8  ;  membranes 
of  nervous  centres,  468-72  ;  chemical  com- 
position of  nervous  centres,  473  j  functions, 
474  ;  pathological  states,  475  \ 

Nervous  system,  structure  of,  437-75  ;  struc- 
ture of  nerves,  438-54  ;  structure  of  nerv- 
ous centres,  465-72 

Nervous  tissue,  423-37  ;  fibrous  nerve  tissue, 
423-34 ;  the  nurilemma,  neurine,  425 ; 
axis-fibre,  425 ;  medulla  or  pulp,  426 ; 
coarse  fibres,  424-27;  nervine,  426;  non- 
medullated  fibres,  426  ;  fine  fibres,  427-29; 
chemical  composition,  function,  430  ;  de- 
velopment, 431-3 ;  growth,  regeneration, 
433  ;  pathological  state  and  new  forma- 
tions, 433  ;  cellular  nerve  tissue,  434-37 

Neurilemma,  425 

New  formation  of  bone,  366 

New  formations  of  epithelium,  248  ;  of  hair, 
267  ;  elastic  tissue,  274 ;  white  fibres,  do. 
283  ;  areolar  tissue,  295 

New  formations  of  nerve  cells,  437 

of  smooth  muscular  fibre,  392 

of  striated  do.  do.,  407 

of   sweat-ducts,    494  ;    of  sebaceous 

glands,  494 

New  membranes,  497 

Nitrogen,  where  found  free  in  the  body,  44  ; 
its  amount ;  is  dissolved  in  the  blood,  44  ; 
in  the  sweat,  230 

Non-striated  muscular  fibre,  384—92 

Nuclear  fibres,  113,  273 

Nuclei,  116;  pathological  do.  117-19;  free 
do.,  115 

Nucleoli,  119 

Number  of  blood  corpuscles,  167 


0. 


Obe.sity,  cases  of,  300  ;  remedy  for,  300 
(Edema,  294 


■  of  lungs,  582 


<T]sophngus,  its  structure,  522 

Oidium  albicans,  248 

Oleine,  76 

Olfactory  nerve,  448  ;  structure  and  distri- 
bution. 448-9 

Optic  chiasma,  449,  464 

Optic  nerve,  449-53  ;  optic  chiasma,  449  ; 
the  retina ;  its  five  layers,  450-53  ;  the 
rods  and  cones,  452  ;  optic  thalami,  464 

Oral  cavity,  514-22  ;  epithelium  ;  corium, 
522  ;  papillw  of  tongue,  515-18  ;  glands 
of  oral  cavity,  519-20  ;  tonsils,  521;  sali- 
vary glands,  521 

Organic  immediate  principles,  definition,  80; 


classification,  41 ;  general  remarks,  80-3  ; 
are  alone  assimilable,  82  ;  their  metamor- 
phosis, 83  ;  have  no  fixed  chemical  compo- 
sition, 80  ;  source  of  materials  for  their 
formation,  81  ;  earthy  salts  unite  with 
them,  80  ;  contain  much  water,  46  ;  natu- 
rally fluid  ;  albumen  ;  caseine  ;  fibrine, 
&c.,  84-96;  solid  or  demisolid ;  muscu- 
line,  osteine  <fcc.,  96-101 ;  coloring,  do^; 
urine  pigments ;  bile  pigments ;  do.  in 
diseases,  101 ;  haematine,  101-3 ;  melan- 
ine,  103 

Organs  of  senses,  594-604;  of  touch,  476-94; 
of  taste  515-18  ;  smell,  448  ;  hearing,  453, 
594-6  ;  vision,  449-53,  597-604 

Osseous  tissue,  321-36  ;  ultimate  granules, 
321  ;  lacunas  and  pores,  323  ;  Haversian 
canals,  324 ;  Haversian  spaces,  325  :  can- 
cellated bone  structure,  327  ;  compact  do., 
328-31;  chemical  composition,  332-5  ;  pro- 
perties and  uses  ;  distribution,  335  ;  do.  in 
lower  animals,  336 

Ossification  of  muscles,  407 ;  in  various  tis- 
sues, 366 

Osteine  in  bone  and  white  fibrous  tissue  ; 
relation  to  glutin,  98;  amount  in  bones; 
how  formed  ;  uses ;  is  nutritious ;  glutin 
not  so,  99 

Osteomalacia,  335 

Osteophytes,  335,  365 

Osteoporosis,  335,  366 

Osteopsathyrosis,  366 

Osteosclerosis,  365 

Otoliths,  453 

Ovaries,  565;  ovisac,  566 ;  corpora  lutea,  567 

Oviducts,  563 

Ovisac,  565 

Oxalate  of  lime  ;  where  found,  64 ;  origin, 
66  ;  forms  of  crystals,  65  ;  do.  do.  calculus, 
66; 

Oxalic  acid,  66 

Oxalic  diathesis,  a  fiction,  67 

Oxygen,  where  found,  free,  in  the  blood,  43; 
its  amount,  43  ;  uses,  quantity  annually 
consumed  by  an  adult,  43  ;  in  a  liquid 
state  in  the  blood,  43 


Pacchionian  bodies,  406 

Pacinian  bodies,  442;   on  bones,  339 

Pancreas,  540  ;  its  ducts,  vessels,  and  nerves, 

541 
Pancreatine,  83,  213 
Pancreatic  fluid,  properties,  quantity,  origin, 

uses,  213 
Panniculus  adiposus,  289,  299,  twte 
Papillaj   of  tongue,  filiform   and  fungiform, 

615 

circumvnllatiV),  516 

of  hair,  259 


Papilloma,  247 
Paralysis,  403 
Paralyzed  muscles,  406 
Parasites  in  muscles,  407 
Pathological  states  of  sebaceous  glands,  494 
Pathological   states  of   nerve-cells,   437 ;    of 
other  tissues  {sec  each  tissue) 


INDEX. 


613 


Pavement-epithelium,  237 

Penis,  itfi  structure,  551-3 ;  its  nerves,  553  ; 

erection  of,  558 
Pemphigus,  493 
Pepsine,  109  ;  action  of,  200 
Peptic  glands,  525 
Peptones,  200 
Pericardium,  498 

Perichondrium,  279  ;  perichondritis,  320-5 
Perimysium,  289 

Perineurium,  276,  280,  286,  410,  438 
Periosteum,  279,  341 ;  structure  of  two  layers, 
342  ;  bone  surfaces  not  covered  by  it,  342 ; 
pathological  states  of,  366 
Permanent  teeth,  382 

Perspiration,   properties,   228  ;    composition, 
229  ;  gases  contained  in  it,  amount,  229  ; 
origin,  uses,  effects  of  a  "  check  of  perspi- 
ration," 231 
Perspiratory  glands,  229 
Peyer's  patches,  530 
Pharynx,  its  structure,  522 
Phosphates  of  ammonia,  and  magnesia,  56 

of  magnesia,  distribution  ;   in  bone, 

varies  with  phosphate  of  lime  ;  more  abun- 
dant than  the  latter  in  muscle,  origin  ; 
how  evacuated,  56 
Phosphate  of  lime,  in  every  fluid  and  solid 
of  the  body ;  proportion  in  different  parts, 
bones,  blood,  &c.,  54;  combined  in  bone 
with  osteine  ;  forms  as  a  urinary  deposit ; 
uses  ;  origin  ;  how  leaves  the  body  ;  acid 
phosphate  of  lime,  65  ;  calculus  of  phos- 
phate of  lime,  54 
Phosphate  of  potassa,  abounds  in  muscles  of 

calf;  origin,  68 
Phosphates  (neutral  and  acid),  of  soda,  as 
immediate  principles,  67-68;  in  urine,  218 
Phosphates  in  brain,  &c.,  473 
Phosphorus  in  brain,  &c.,36  ;  with  albumen, 

85 
Physiology  of  cells,  126-129 
Pia  mater,  468-9 

Pigment-cells,  131-137 ;  peculiarities,  distri- 
bution, 131;  in  skin  of  negro  ;  in  lungs; 
freckles,  132  ;  peculiar  forms ;  pigmentum 
nigrum  ;  do.  of  lower  animals,  133  ;  color 
of  hair  and  eyes,  134 ;  acne  ;  development 
of  pigment-cells  ;  function,  135  ;  regenera- 
tion, 136  ;  pathological  formations,  137 
Pigmentary  degeneration,  of  cells,  130 
Pigmentum  nigrum,  133 
Pineal  body,  466 
Pituitary  body,  465 
Plasma,  95 

Plethora,  the  blood  in,  178 
Pleura,  675 
Pneumate  of  soda,  67 
Pneumic  acid,  67 
Pneumatosis,  294,  5 
Pneumogastric  nerve,  446 
Polypi,  of  the  stomach,  498;  do.  heart,  95 
Pons  Varolii,  460 
Portal  canals,  633 
Portal-hepatic  plexus,  532 
Portal  vein,  633  ;  peculiaritj'of  its  blood,  174 
Potassa,  carbonate  and  bicarbonate  of,  53 

sulphate  of,  63 

Potassium,  36  (sec  Chloride  of  potassium) 


Pores  of  bone,  323 

Pregnancy,  changes  in  uterus  during,  505 
composition  of  the  blood  in,  173 


Primary  bones,  350 
Principles,  immediate  (see  Immediate  princi- 
ples) 
Primordial  cells,  130 
Proteine,  83  ;  its  compounds,  83,  90,  note 
Prostate  gland,  553 
Prurigo,  494 

Puerperal  fever,  the  blood  in,  178 
Pulmonary  arteries,  570 
Pulp  of  spleen,  584 

of  teeth,  375,  378 


Pus,  albumen  in,  87 ;  origin  of,  189  ;  compo- 
sition, 189  ;  liquor  puris,  189  ;  pus-corpus- 
cles, 190  ;  how  long  is  pus  in  forming,  192 

Pus-corpuscle,  116,  145,  190,  192  j  uses,  193; 
how  formed,  191 ;  relation  to  exudation- 
corpuscle,  188  ;  time  required  for  their  de- 
velopment, 191;  stearosis  of,  192:  "ste- 
rile cells,"  192 

Ptyaline,  83 

Pyemia,  160 ;  the  blood  in,  178 

Pyramids  of  Malpighii,  542 

of  Ferrein,  543 


Q 

Quantity  of  the  blood,  173 


R 

Rachitis,  335 

Regeneration  of  areolar  tissue,  293  ;  of  the 
other  tissues  (5ee  each  particular  tissue),  486 

Reparation  of  bones,  363;  after  fracture,  364 

Respiratory  organs,  572,  582  ;  air-passages  ; 
nasal  passages,  572  ;  larynx,  673  ;  trachea, 
674;  lungs,  575,  580  ;  development;  func 
tion  of  respiratory  apparatus,  580  ;  patho- 
logical states  of  lungs,  581 

Reticular  cartilages,  314 

Retina,  five  layers  of,  450-3 ;  its  rods  and 
cones,  452 

Richardson,  Dr.,  on  causes  of  fluidity  of  the 
blood,  95,  note 

Rigor  mortis,  403-5  ;  duration  ;  order  of  ap- 
pearance ;  how  modified  by  electricitj', 
404—5  ;  in  smooth,  muscular  fibres  also,  405 

Rodentia,  hairs  of,  267 

Roots  of  spinal  nerves,  439 

Rubeola,  403 

RugSB  of  vagina,  562 

Ruptured  muscular  fibre,  407 


S 


Sacculi  of  hepatic  ducts,  537 

Saliva,  properties,  209  ;  do    of  each  salivary 

gland  ;    quantity,   209  ;    origin  and   uses  ; 

chemical  agency,  210 
Salivary  glands,  structure  of,  521 
Salt,  common  {scr  Chloride  of  sodium) 
Salts  in  human  body,  47-58  ;  general  remarks. 

48  ;  in  liquor  sanguinis,  uses,  166  ;  in  what 

diseases  increased  or  diminished,  179 


39= 


614 


INDEX. 


Saponifiable  fats,  77 

Sarcomatous  tumors,  283 

Scarlatina,  493 

Scirrhosis,  137 

Sclerosis,  334,  365 

Sclerotic  coat,  597 

Sebaceous  glands,  486-8  ;  minute  structure, 
488  ;  development,  488 

Sebaceous  secretion,  properties,  225  ;  acarus 
folliculorum,  226  ;  vernix  caseosa ;  casto- 
reum  ;  origin  of  sebaceous  fluid,  227;  uses, 
228  ;  Meibomian  fluid  ;  cerumen,  228 

Secondary  bones,  350-8  ;  development,  359- 
362 

Secretion  by  cells,  129  ;  on  serous  membrane, 
179—181 

Semen,  207-9  ;  liquor  seminis  ;  spermatozoids, 
207  ;  agents  destroying  their  motion,  192  ; 
seminal  granules  or  spermatophori,  208 ; 
development  of  spermatozoids ;  recognition 
of,  208  ;   origin  and  uses,  209 

Seminiferous  tubes,  556-7 

Sensibility  of  muscles,  421 

of  teeth,  376 

Sepia,  134 

Seroline,  a  compound  substance,  75 

Serous  membrane,  496  ;  function,  496 

pathological  state  of,  496 

Serous  secretions,  179-181 ;  distinguished 
from  transudations  and  exudations,  180  ; 
enumeration  and  composition,  180  ;  vary- 
ing amounts  of  albumen  in,  181 ;  their 
quantity,  origin,  and  uses,  181 

Serum  of  blood,  153—4  ;  composition,  153 

Sesamoid  bones,  419 

Sex,  efiect  on  composition  of  blood,  173 

Sexual  organs,  550 — 572  ;  of  the  male,  550-8  ; 
of  the  female,  559 — 572  ;  male  urethra,  550  ; 
penis,  551;  prostate  gland,  553;  vesiculae 
seminales,  553  ;  testes,  554—7  ;  the  semen, 
558  ;  the  vulva  ;  vagina,  559  ;  uterus  and 
oviducts,  560-5  ;  ovaries,  565  ;  ovum,  556  ; 
corpora  lutea,  567  ;  sensibility  of  the  ute- 
rus, 569  ;  lacteal  glands,  569 — 571 ;  nipple 
and  areola,  570 

Sheaths  of  tendons,  418 

Sheep,  milk  of,  206 

Silicum,  37 

Simple  fibre  ;  description  ;  in  membranaputa- 
minis ;  in  inflammatory  exudation,  112; 
uses  ;  four  forms  in  morbid  growths,  113 

Simple  membrane,  description;  microscopic 
appearance,  109 ;  two  forms ;  its  proper- 
ties ;  distribution,  110 ;  basement  mem- 
brane, uses,  111 ;  simple  membrane  in  vege- 
table cells,  110,  twte 

Sixth  pair  of  nerves,  447 

Skin,  structure  of,  476-86 

its  corium,  476-7  ;  papillae,  477  ;  their  size 
and  distribution,  478;  basement  membrane 
of  skin,  epithelium,  479 ;  its  thickness, 
480  ;  thickness  of  stratum  Malpighii,  481  ; 
composition  and  properties  of  skin,  482  ; 
vessels,  482  ;  lymphatics,  483  ;  nerves,  483  ; 
development,  484 ;  its  growth,  485 ;  re- 
generation, 486  ;  functions,  492-3  ;  patho- 
logical conditions,  493 

Skeleton,  its  comparative  weight,  348,    iwte 


Small  intestine,  structure,  526-31 ;  glands 
of,  528-31 

Smegma  prseputii,  226  and  iwte,  485 

Smooth  muscular  fibres,  384 

Soda,  carbonate  and  bicarbonate,  52  ;  phos- 
phates, 57  ;  sulphates  of,  53 

Sodium,  36  [see  Chloride  of) 

Softening  of  muscles,  407 

Solids  and  fluids,  proportion  in  human  body, 
32 

Spasm,  various  kinds,  403 

Spermaceti,  303 

Spermatophori,  208 

Spermatozoids,  116;  description  of,  207;  de- 
velopment, 208,  557  ;  in  urine,  214;  move- 
ments of,  558 

Spinal  nerves,  structure  of,  439^3 ;  their 
roots,  439  ;  ganglia,  439 ;  ganglion-cells, 
439  ;  ganglion-fibres,  441 ;  proportion  of 
coarse  fibres  in  spinal  nerves,  441 ;  Pacinian 
bodies,  442-3 

Spinal  accessory  nerve,  447 

Spinal  cord,  456-60 ;  longitudinal  fibres,  456  ; 
horizontal  do.,  457;  fibres  in  gray  sub- 
stance, 457 ;  motor  fibres,  458 ;  sensitive 
roots,  458  ;  gray  substance  of  cord,  459 

Spiral  fibre  of  insects,  113,  note 

Spleen,  583-87;  its  envelops,  583;  pulp,  584; 
Malpighian  bodies,  585-6 ;  vessels,  586  ; 
functions,  development,  587 

Splenic  vein,  peculiarities  of  its  blood,  175 

Splenization  of  lungs,  582 

Sputa  of  acute  pneumonitis,  192 

Stearine,  76 

Stearosis,  74,  78  ;  of  cells,  179  ;  bones,  309, 
366 ;  heart,  muscles,  kidney,  310,  549 ; 
liver,  311;  arteries,  312;  cartilage,  320; 
capillaries,  513  ;  of  epithelial  cells  of  bron- 
chial tubes,  582  ;  of  smooth  muscular  fibre, 
392;  do.  of  striated  do.  do.,  406 

Steatoma,  308 

Sterile  cells,  192 

Stoechiology,  definition,  35 

Stomach,  its  structure,  523  ;  hepatic  glands, 
524-5 

Strength  of  bones,  348-9 

Striated  muscular  fibre,  392-408 ;  the  myo- 
lemma,  393,  396  ;  myoline,  fibrill»,  394  ; 
chemical  composition  of,  394,  396  ;  muscu- 
lar fluid,  395;  musculine,  color  of  striated 
fibres,  their  distribution,  397  ;  do.  and  pe- 
culiar forms  in  lower  animals,  398 ;  de- 
velopment, 399  ;  function  of  striated  fibres, 
contractility,  401-20  ;  heat  evolved  during 
contraction,  tonicity,  402;  modified  con- 
tractility, spasm,  403  ;  rigor  mortis,  403-5  ; 
pathological  states  of  striated  fibres,  406-7 

Striped  lamellae,  503,  508,  509 

Styptics,  action  explained,  86 

Substantia  grisea,  do.  gelatinosa,  456-8 

Sudoriferous  glands  {see  Sweat  glands),  489- 
92 

Sugar  of  liver  and  of  milk,  remarks  on,  70  ; 
of  milk,  its  quantity,  origin,  uses,  72;  its 
metamorphoses,  72 

Sulphate  of  soda,  where  found  in  the  body, 
uses,  origin,  53 

of  potassa,  amount  in  the  blood,  uses. 


53 


INDEX. 


615 


Sulphate  of  lime,  as  an  immediate  principle, 
54 

Sulphur,  36  ;  with  albumen,  85 

Superficial  fascia,  289-90 ;  its  attachment, 
thickness,  relation  to  arteries,  290 

Supra-renal  glands,  592-3  ;  cortical  and  me- 
dullary portions,  593  ;  nerves  and  vessels, 
function,  development,  693 

Suppuration,  187 ;  when  desirable,  193  ;  when 
not,  193 

Sweat  ducts,  490 

Sweat  glands,  229,  489-92 ;  number,  aggre- 
gated length,  480  ;  minute  structure,  490  ; 
development,  491 ;  pathological  states, 
494  ;  ceruminous  glands,  492 

Sweat  {see  Perspiration),  228 

Synarthrosis,  347 

Synovial  bursas,  195 

Synovial  membranes,  344,  496 ;  not  closed 
sacs,  intimate  structure,  epithelium,  vas- 
cular processes,  synovia,  345 ;  synovial 
sacs,  418 

Sympathetic  nerve-fibres,  so  called,  428 


Tarsal  cartilages,  604 

Tartar  of  teeth,  388 

Teeth,  374-83 ;  cortical  portion ;  pulp,  375, 
378  ;  the  gum  ;  alveolar  periosteum,  375  ; 
uses  of  teeth,  375  ;  their  sensibility,  376  ; 
development,  376-81  ;  formative  stages, 
376  ;  development  of  dentine,  379  ;  of  ena- 
mel, 380  ;  cementum,  381 ;  eruption  of 
milk  teeth,  381 ;  of  permanent  teeth,  382  ; 
growth  of  teeth,  382  ;  pathological  states, 
382  ;  abnormal  developments  of,  383 

Tendency  to  sink,  of  blood-corpuscles,  165 

Tendons  and  ligaments,  how  connected  with 
bones,  346 

Tendons,  structure  of,  408-9 ;  composition, 
409 

connection  with  bones,  &c.,  411-12 

development,  422 

vessels  of;  structure;  do.  of  aponeu- 
roses, 278 

Tessellated  epithelium,  237 

Testes,  554-7;  structure  of  seminiferous  tubes, 
556-7 

Testis,  section  of,  279 

Tetanus,  403 

Third  pair  of  nerves,  447 

Thoracic  duct,  509 

Thymus  gland,  590-2 ;  its  structure,  590 ; 
involution  ;  function,  591 

Thyroid  gland,  588-9  ;  its  vessels  ;  patholo- 
gical enlargements,  589  ;  analysis  of,  589 

Tissues,  classification  of  the,  233 

Tongue,  its  mucous  membrane  and  papilla?, 
515-18  ;  affections  in  disease,  518 

Tonicity,  402 

Tonsils,  structure  of,  521 

Tcrula  cerevisiae,  70,  note  ;  in  urine,  216 

Trachea,  its  structure,  574 

Trachese  of  insects,  113,  note;  and  172 

Transudations,  86,  181-3  ;  distinguished  from 
serous  secretions  and  exudations,  180  ; 
enumeration,  colliquative  sweats,  diarrhoea, 


Ac,  181 ;  are  a  physical  necessity,  when, 
182;  normally  contain  no  fibrine  ;  vary- 
ing quantity  of  albumen  in,  182 ;  do.  com- 
po.fition  of,  183  ;  do.  quantity  ;  uses,  183 

Trigeminus  nerve,  446 

Trismus,  403 

Tubercle-corpuscles,  117;  analysis  of,  118; 
contain  little  fat,  distinguished  from  pus- 
corpuscles,  118 ;  cretaceous  transformation, 
118 

Tubercle  in  air-cells  of  the  lungs,  582 ;  of 
bone,  366 

Tubes  of  crystalline  lens,  601 

Tubuli  of  teeth,  369 

Tubuli  uriniferi ;  do.  contorti,  543 


U 


Ulceration,  of  cartilage,  319 

Urate  of  soda,  63;  do.  of  ammonia,  63 

Urea  diathesis  disproved,  69 

Urea ;  its  crystals ;  where  found  ;  where  in  dis- 
ease, 69  ;  origin  ;  increased  in  delirium  tre- 
mens, 69  ;  amount  in  urine,  217-18 

Ureters,  542 

Urethra,  of  female,  541;  of  male,  550 

Uric  acid  diathesis  disproved,  66 

Uric  acid  ;  proportion  in  urine  ;  various  forms 
of  its  crystals  ;  circumstances  increasing  it, 
62  ;  calculus  of  uric  acid  ;  urate  of  soda  do. ; 
lateritious  sediment,  63  ;  urate  of  ammonia  ; 
form  of  crystals,  64 ;  amount  in  urine,  218 

Urinary  concretions  (calculi) ,  22.3-4 

Urinary  apparatus,  541 — 550  ;  bladder,  541 ; 
ureters,  542;  kidney,  542-8 

Urinary  deposits,  222-3 

Urinary  passages,  541 

Urine  ;  properties  ;  morphological  elements 
in,  214  ;  spermatozoids  in  ;  epithelial  cells  ; 
pus-corpuscles;  mucus  do.,  214;  blood-cor- 
puscles ;  casts  of  tubuli  ;  fibrinous  casts  ; 
organic  globules,  large  and  small,  215  ; 
torula ;  vibriones,  2 ;  sarcina  ventriculi, 
216  ;  chemical  analysis  ;  urea  increases  with 
spec,  gravity,  217  ;  and  with  other  circum- 
stances, 218;  uric  acid,  formic,  lactic,  crea- 
tine, creatinine,  chlorides,  and  sulphates, 
218  ;  substances  passing  unaltered  into  the 
urine  ;  rapidity  of  passage,  219  ;  abnormal 
elements  in  urine,  219,  220  ;  quantity  of 
urine,  220  ;  origin  of,  221 ;  uses,  222  ;  uri- 
nary deposits,  223  ;   urinary  calculi,  223-4 

Uterus  and  oviducts,  560-5  ;  structure  of  ute- 
rus, 560-3  ;  its  glands,  561  ;  its  cervix,  struc- 
ture, 562-3  ;  ovulaNabothi,  563  ;  oviducts, 
563  ;  round  ligaments ;  broad  do.  ;  do.  ova- 
rian, 564  ;  changes  in  the  uterus  during 
menstruation,  564  ;  do.  during  pregnane}-, 
566  ;  its  smooth,  muscular  fibre,  3SS-9 


Vagina,   560  ;   its  papilla; ;  nerves ;  vessels 

560  ;  its  sensibility,  569 
Valves,  auriculo-ventricular ;  do.  semilunar 

499 
Variety  of  aliment  necessary,  37 


616 


INDEX. 


Varix,  513 

Vasa  deferentia,  554 

Vasa  serosa,  606 

Yasa  vasorum,  503 

Vascular  membranes,  279 

Vascular  system,  498,  513 ;  functions,  deve- 
lopment, 511-13 

Veins,  506  ;  coats  of  smallest,  506  ;  do.  of 
medium-sized,  507  ;  do,  of  large  veins,  508  ; 
peculiarities,  508;  valves  of  veins,  608;  de- 
velopment, 511 

Veins  of  bones,  337 

Vernix  caseosa,  226-7,  485 

Verruca  (warts),  247,  494 

Vesieulaj  seminales,  553 

Vesical  calculi,  223-4 

Vessels,  adipose,  297 ;  of  heart,  499  ;  of 
smooth  muscular  fibre,  386  ;  do.  of  striated 
do.,  413  ;  of  teeth,  375  ;  of  other  tissues 
(see  each  particular  tissue) 

Vestibular  nerves,  453 

Villi,  326-28  ;  function  of,  528 

Vibriones  in  mucus,  196  ;  do.  in  milk,  203 

Vitreous  body,  603 

Vulva,  559 ;  its  sensibility,  569 


W 


Water,  in  every  tissue  and  fluid  of  body  ; 
quantity  ;  mass  ;  proportional  amount  in 
several  tissues  and  fluids  ;  as  a  remedy  for 
disease,  46  ;  is  in  a  solid  state  in  the  tis- 
sues ;  great  amount  fixed  by  the  organic 
substances;  more  in  muscles  of  young  ani- 


mals ;  source  of  the  water,  46 ;  quantity 
consumed  annually  by  an  adult ;  uses  in 
the  body ;  how  leaves  the  body,  47  ;  amount 
in  the  blood,  153  ;  uses  there,  155  ;  in  bone, 
332 

Whale,  aorta  of,  272  ;  fat  of,  303 

White  fibrous  tissue,  276  to  284  ;  description, 
276  ;  chemical  composition,  276  ;  proper- 
ties, uses,  distribution,  277 ;  structure  of 
tendons  and  ligaments ;  fibro-cartilages, 
278 ;  fibrous  membranes,  tunics  of  testis, 
ovaries,  &c. ;  vascular  membranes,  279  ; 
the  cornea,  its  structure,  280  ;  connection 
with  sclerotica,  vessels  of  cornea,  281 ;  dis- 
tribution of  collagenous  tissue  in  lower  ani- 
mals, 282  ;  development,  282  ;  growth  ;  re- 
paration ;  pathological  states;  cirrhosis; 
condylomata;  keloides,  283;  lupus  exe- 
dens,  284 


Yeast  fungus,  70,  note 

Yellow  fibrous  tissue,  268,  275  ;  three  forms, 
268  ;  arrangement,  chemical  composition, 
270;  properties  and  uses ;  distribution,  271; 
distribution  in  lower  animals,  272  ;  deve- 
lopment, 272  ;  growth  and  reparation,  274  ; 
pathological  formations  of,  274 

Yolk  of  ovum,  116 

Yolk  sac,  116 


Zona  pellueida,  566 


PRINCIPAL  WORKS  REFERRED  TO  IN  THIS  VOLUME. 


Gerber's  Elements  of  the  General  and  Minute  Anatomy  of  Man,  and  the  Mam- 
malia.    London, 1842. 

SchwA-Nn's  Microscopical  Researches  into  the  Structure  and  Growth  of  Animals 
and  Plants.     Sydenham  Society.     London,  1847. 

Hassall's  Microscopic  Anatomy  of  the  Human  Body,  in  Health  and  Disease.  New 
York,  1855. 

Todd  and  Bowman's  Physiological  Anatomy  and  Physiology  of  Man.  IV.  Parts. 
London,  1845—57.     (Philadelphia,  1857.) 

Cyclopedia  of  Anatomy  and  Physiology.     London,  1839 — '57. 

Paget's  Lectures  on  Inflammation,  in  Medical  Gazette,  1850. 

Carpenter's  Elements  of  Physiology,  including  Physiological  Anatomy.  Second 
American  edition.     Philadelphia,  1851. 

Gross's  Pathological  Anatomy.     Second  edition.     Philadelphia,  1857. 

G.  Bird,  on  Urinary  Deposits.     Second  American  edition.     Philadelphia,  1851. 

Bowman's  Medical  Chemistry.     Philadelphia,  1853. 

Carpenter's  Principles  of  Human  Physiology.  Fifth  American  edition.  Phila- 
delphia, 1853. 

Simon's  Animal  Chemistry.     Philadelphia,  1846. 

VoGEL,  Pathological  Anatomy  (General).     Philadelphia,  1847. 

Simon  on  the  Thymus  Gland.     London,  1845. 

Gluge's  Pathological  Histology.  1  vol.  folio.  American  edition.  Philadelphia, 
1855. 

Robin  and  Verdeil,  Anatomical  and  Physiological  Chemistry.   3  vols.   Paris,  1853. 

Queckett's  Lectures  on  Histology.     2  vols.     London,  1852 — 54. 

Gray  on  the  Structure  and  Use  of  the  Spleen.     London,  1854. 

Kollikek's  Human  Microscopic  Anatomy.  2  vols.  Sydenham  Society.  London, 
1854—56. 

.Jones  and  Sieveking's  Pathological  Anatomy.     Philadelphia,  1854. 

Lehmann's  Physiological  Chemistry.     2  vols.     Philadelphia,  1855. 

W.  Tyler  Smith  on  the  Pathology  and  Treatment  of  Leucorrhoea.  Philadelphia, 
1856. 

Wedl's  Pathological  Histology.     1  vol.     Sydenham  Society.     London,  1855. 

Lehmann's  Chemical  Physiology.     Philadelphia,  1856. 

Carpenter  on  the  Microscope.     Philadelphia,  1856. 

Beale  on  the  Anatomy  of  the  Liver.     London,  1856. 


ERRATA. 


Page    44,  2d  line  from  bottom,  for  "pneumonic  "  read  " pneumic." 
"       71,  2d  line     "  "         of  foot  note,  for  "proportions,"  read 

"propositions." 
"     236,  line  12th,  and  page  508,  line  17tli  from  bottom,  for  "  when," 

read  "  where." 
"     265,  4th  line  from  bottom,  for  "  J,"  read  "  yV-" 
"     425,  line  10th,  for  "  its,"  read  "  their." 

"     428,  lines  6th  and  15th,  for  "Pacchionian,"  read  "Pacinian.'^ 
"     489,  line  9th  from  bottom,  for  "  39,653,"  read  "  39,653(?)." 


HEIsTRY    C.     LEA.'S 

(LATE  LEA  &  BLANCHARD'S,) 

MEDICAL  AND  SURGICAL  PUBLICATIONS. 


TO  THE  MEDICAL  PROFESSION. 

The  prices  on  this  Catalogue  are  tliose  at  which  these  books  can  generally  be 
furnished  by  booksellers,  who  can  readily  procure  for  their  customers  any  which 
they  may  not  have  on  hand.  Where  access  to  bookstores  is  not  convenient,  I 
will  forward  them  at  these  prices,  free  hy  mail,  to  any  post  office  in  the  United 
States.  In  all  cases  the  amount  must  accompany  the  order,  as  accounts  are  opened 
only  with  dealers ;  I  assume  no  risks  of  the  mail,  either  on  the  money  or  the 
books,  and  can  supply  nothing  but  my  own  publications.  Gentlemen  desirous 
of  purchasing  will,  therefore,  find  it  more  advantageous  to  deal  with  the  nearest 
bookseller  whenever  practicable,  or  to  send  orders  through  their  merchants  visit- 
ing the  larger  cities.  HENRY  C,  LEA. 

Nos.  706  and  708  Sansom  Street,  Philadelphia,  March,  1866. 

*^*  Just  issued,  a  revised  Illustrated  Catalogue  of  Medical  and  Scientific 
Publications,  forming  an  octavo  pamphlet  of  80  large  pages,  containing  specimens 
of  illustrations,  notices  of  the  medical  press,  &c.  &c.  It  has  been  prepared  with- 
out regard  to  expense,  and  will  be  found  one  of  the  handsomest  specimens  of 
typographical  execution  as  yet  presented  in  this  country.  Copies  will  be  sent  to 
any  address,  by  mail,  free  of  postage,  on  receipt  of  nine  cents  in  stamps. 

Catalogues  of  publications  in  miscellaneous  and  educational  literature  forwarded 
on  application- 


s'^ The  attention  of  physicians  is  especially  solicited  to  the  following  important  new  works 
and  new  editions,  just  issued  or  nearly  ready : — 

Ashton  on  the  Recluni,  new  edition, See  page 


Brinton  on  the  Stomach, 

Bennett  on  the  Uterus,  sixth  edition,     .... 

Bowman's  Medical  Chemistry,  Jourth  edition, 
Bunibiead  on  Venereal,  second  edition, 
Barclay  on  Medical  Diagnosis,  third  edition, 
Brande  and  Taylor's  Chemistry,  ...... 

Dalion's  Human  Physiology,  3d  edition, 

Dunglison's  Medical  Dictionary,  a  revised  edition,  1865, 

Eilib' Formularj^,  new  edition, 

Erichsen's  System  of  Surgery,  a  revised  edition,         , 
Flint's  Practice  of  Medicine,  now  ready. 
Gross's  System  of  Surgery,  third  edition,     ... 
Gray's  Anatomy,  Descriptive  and  Surgical,  2d  edition, 

Hillier  on  Skin  Diseases, 

Hamilton  on  Fractures  and  Dislocations,  second  edition, 

Hodge's  Obstetrics, 

Pereira's  Materia  Medica,  condensed  edition,  preparing, 

Roberts  on  Urinary  Diseases,  now  ready, 

Parrish's  Practical  Pharmacy,  a  new  edition, 

Smith  on  Consumption,  ...... 

Stille's  Therapeutics  and  Materia  Medica,  second  edition, 
Wilson  on  the  Skjn,  tilth  edition,  ..... 

Winslow  on  the  Brain  and  Mind,  second  edition. 
West  on  Children,  fourth  edition,  .... 


4 

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5 

6 

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12 

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14 

15 

16 

17 

18 

18 

19 

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26 

27 

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32 

32 


THE  AMERICAN  JOURNAL  OF  THE  MEDICAL  SCIENCES 

AND  THE  MEDICAL  NEWS  AND  LIBRARY, 
For  FIVE  DOLI^ARS  per  auaiuiii,  invariably  iu  Advance. 

To  avoid  raising  the  price  at  which  the  "Medical  Journal"  has  been  published  for  nearly  fifty 
years,  subscriptions  are  now  only  taken  payable  in  advance.  The  result  of  this  policy  during  1S65 
has  been  a  largely  increased  subscription  list,  which  has  exhausted  the  whole  edition  prmted.  J4c 
copies  can  be  supplied  for  1865,  and  subscriptions  can  novf  only  be  received  for  1866 


HENRY   C.    LEA'S  MEDICAL 


BUDD  (GEORGE),  M.  D.,  F.  R.  S., 

Professor  of  Medicine  in  King's  College,  London. 

ON   DISEASES   OF   THE   LIVER.      Third   American,  from   the  third   and 

enlarged  London  edition.    In  one  very  handsome  octavo  volume,  extra  cloth,  with  four  beauti- 
fully colored  plates,  and  numerous  wood-cuts.     pp.  500.     $4  GO. 


Has  fairly  established  for  itself  a  place  among  the 
classical  medical  literature  of  England.— SrifMA 
and  Foreign  MedUo-Chir.  Review. 


the  text  the  most  striking  novelties  which  have  cha- 
racterized the  recentprogress  of  hepatic  physiology 
ind  pathology :  so  thatalthough  the  size  of  the  book 
r    u     I-  is  not  perceptibly  changed,  the  history  of  liver  di8- 

Dr.  Budd'B  Treatise  on  Diseases  of  the  biver  is  j  eases  is  made  more  complete,  and  is  kept  upon  a  level 
now  a  standard  work  in  Medical  literature,  and  dur-  .5^,;^!,  ^^^  progress  of  modern  science.  It  is  the  best 
ing  the  intervals  which  have  elapsed  between  the  ^^rk  on  Diseases  of  the  Liver  in  any  language- 
successive  editions,  the  author  has  incorporated  into    London  Med.  Times  and  Gazette . 


BUCKNILL  (J.  C),   M.  D.,  and        DANIEL   H.   TUKE,    M.  D., 

Medical  Superintendent  of  the  Devon  Lunatic  Asylum.        Visiting  Medical  Officer  to  the  York  Retreat. 

A  MANUAL  OP   PSYCHOLOGICAL   MEDICINE;   containing  the  History, 

Nosology,  Description,  Statistics,  Diagnosis,  Pathology,  and  Treatment  of  INSANITY.  With 
a  Plate.  In  one  handsome  octavo  volume,  of  5.36  pages,  extra  cloth.  $4  25. 
The  increase  ot  mental  disease  in  its  various  lorms,  and  the  difficult  questions  to  which  it  is 
constantly  giving  rise,  render  the  subject  one  of  daily  enhanced  interest,  requiring  on  the  part  of 
the  physician  a  constantly  greater  familiarity  with  this,  the  most  perplexing  branch  of  his  profes- 
sion. Yet  until  the  appearance  of  the  present  volume  there  has  been  for  some  years  no  work  ac- 
cessible  in  this  country,  pre.-enting  the  results  of  recent  investigations  in  the  Diagnosis  and  Prog- 
nosis of  Insanity,  and  the  greatly  improved  methods  of  treatment  which  have  done  so  much  in 
alleviating  the  condition  or  restoring  the  health  of  the  insane. 

BENNETT   (HENRY).  M.  D. 
A  PRACTICAL   TREATISE   ON  INFLAMMATION  OF  THE  UTERUS, 

ITS  CERVIX  AND   APPENDAGES,  and  on  its  connection  with  Uterine  Disease.     Sijilh 

American,  from  the  fourth  and   revised  English  edition.     In  one  octavo  volume,  of  about  500 

pages,  extra  cloth.  $3  75.     (Just  Issued.) 

This  standard  work,  which  has  done  so  much  to  introduce  the  modern  and  improved  treatment 
of  female  dii-eases,  has  received  a  very  careful  revision  at  the  hands  of  the  author.  In  his  preface 
be  states  :  "  During  the  past  two  years  this  revinon  of  former  U.bors  has  been  my  principal  occupa- 
tion and  in  its  present  state  the  vi/ork  may  be  considered  to  embody  the  matured  experience  of  the 
many  years  I  have  devoted  to  the  study  of  uterine  disease." 

BRINTON   (WILLIAM),    M.  D      F.  R.  S., 

Physician  to  St.  Tlionias's  Hospital. 

LECTURES  ON  THE  DISEASES  OF  THE  STOMACH,  with  an  introduc- 
tion on  its  Anatomy  and  Physiology.  From  the  second  and  enlarged  London  edition.  With 
illustrations  on  wood.  In  one  large  and  handsome  octavo  volume.  $3  25.  (Jnst  R'ady.) 
The  entire   series  of  lectures   embraced   in   the 

volume  before  us  are  well  worthy  of  a  close  study 

on  the  part  of  every  one  desirous  of  acquiring  cor- 
rect views  in  relation  to  the  naturf  and  treatment 

of  the  diseases  of  the  stomach.     |Nowhere  can  be 

lound  a  more  full,  accurate,  plain,  and  instructive 

history  of  these  diseases,  or  more  rational   views 

rtsptcting  their  piilliology  and  therapeutics.— .4/we- 

rir.an  .1  ournal  of  Ike  Med.  Sciences,  April,  18G5. 
This  is  n«  mere  ct  mpilalion,  no  crude  record  of 

cases,  but  the  carefully  elaborated  production  of  an  | 


accomplished  physician,  who,  for  many  years,  has 
devoted  special  attenticm  to  the  symptomatology, 
pathology,  and  treatment  of  gastric  diseases. — 
Edinburs;k  Med.  Journal. 

Dr.  Brinton's  position  as  a  laborer  in  medical 
science  and  a  medical  author  is  fully  established, 
and  these  lectures  have  only  added  to  a  reputation 
based  on  many  solid  grounds.  The  work  is  an  im- 
portant one,  and  we  argue  for  it  a  great  place  in 
medical  literature. — London  Lancet,  Dec.  3,  IbOi. 


BOWMAN  (JOHN   E.),  M.D. 
PRACTICAL  HANDBOOK   OF   MEDICAL   CHKMISTRT.    Edited  by  C. 

L  Bix)XAM.    Fourth  American,  from  the  fourth  and  revised  English  Edition.    In  one  neat  volume, 

royal  l2mo., extra  cloth  wiihnumerousilluslrutions.    pp.  35L    $225. 

Of  tliis  well-known  handbi>ok  we  may  say  that 
it  retains  all  its  <.ld  simplicity  and  clcKmess  of  ar- 
rangement and  ciescription,  whilst  it  has  received 
from  the  able  edit  «r  those  finishing  touches  which 
the  progress  of  chemistry  has  rend(  red  necessary  — 
London  Med.  Times  and  Gazette,  Nov. '^9,  lb02. 

Nor  is  anything  huiried  oyer,  anything  shirked  ; 


ject  in  view  lucidly  detailed  and  explained.  And 
this  new  edition  is  not  merely  a  reprint  of  the  last. 
With  a  laudable  desire  to  keep  the  book  up  to  the 
scientific  mark  of  the  present  age,  every  improve- 
ment in  analytical  method  has  been  introduced.  In 
conclusion,  we  would  only  say  that,  familiar  from 
long  acquaintance  with  each  page  of  the  former 
iBKiies  of  this  little  book,  we  gladly  place  iM-side 


best  process  for  the  attaiLiiicnt  01  llie  particular  00-  |  • 


BY  THE  SAME  AUTHOR. 


BY  I  UK  SAME  AUTMUK.. 

INTRODUCTION  TO  PRACTICAL  CHEMISTRY,  INCLUDING  ANA- 
LYSIS. Third  American,  from  the  third  and  revised  London  edition.  With  numerous  illus- 
trations.   In  one  neat  vol.,  royal  12ino.,  extra  cloth.     Sv!  '^5 

This  favorite  little  muiMial  luis  received  a  very  thorough  and  careful  revision  at  the  hands  of  a 
com{)eieiil  editor,  and  will  he  /uiiiid  liilly  brought  up  lo  the  present  condiiion  of  chemical  science. 
Many  portions  have  been  rewriltcn,  the  subjects  of  the  blow-pipe  and  volumetric  analysis  have  re- 
ceived special  attention,  and  an  additional  chapter  has  been  appended.  Siudents  of  practical  chem- 
istry will  therefore  find  it,  as  here  ofore,  a  most  convenient  iuid  condensed  text-book  and  guide  in 
the  operations  of  the  laboratory. 


AND    SCIENTIFIC    PUBLICATIONS. 


BUMSTEAD  (FREEMAN  J  )  M.  D. 
Lecturer  on  Venereal  Diseases  at  tlie  College  i<{  PnyMicmns  urnl  Surijf 


iriB,  New  York,  tea. 


THE   PATHOLOGY   AND   TREATMENT   OF   VENEREAL  DISP]ASES, 

including  the  results  of  recent  invest igui ions  upon  the  subject.     Second  edition,  thorouffhly  re- 
vised and  much  improved.     With  illustriitions  on  wood.    In  one  very  handaome  octavo  volume, 
of  about  700  pages.     S5  00     {Jie.st  Issued.) 
By  far  the  most  valuable  contrihution  to  this  par- 
ticular branch  of  practice  that  lins  seen  the  light 

wittiin  the  last  score  of  years.     His  clear  .-md  accu- 
rate descriptions  of  the  various  forms  of  venereul 

disease,  and  especially  the  methods  of  treatment  he 

projjoses,  are  worthy  of  the  highest  encomium.     In 

these  respects  it  is  better  adapted  for  the  assistance 

of  the  every-day  practiti<mer  than  any  other  with 

which  we  are  acquainted.     In  variety  of  methods 

proposed,  in  minuteness  of  directi(m,  guided  by  eare- 

lul  discrimination  of  varying  forms  and  complica- 
tions, we  write  down  the  book  as  unsurpassed.     It 

is  a  work  which  should  be  in  the  possession  of  every 

practitioner. — Chicago  Med.  Journal.  Nov.  1861. 

The  foregoing  admirable  volume  comes  to  us,  em- 
bracing the  whole  subject  of  syphilohigy,  resolving 

many  a  doubt,  correcting  and  confirming  many  an 

entertained  opinion,  and  in  our  estimation  the  best, 

completest,  fullest  monograph  on  this  subject  in  our 

language.     As  far  as  the  author's  labors  themselves 

are  concerned,  we  feel  it  a  duty  to  say  that  he  has 

not  only  exhausted  his  subject,  but  he  has  presented 

to  us,  without  the  slightest  hyperbole,  the  best  di- 
gested treatise  on  these  diseases  in  our  language. 

He  has  carried  its  literature  down  to  the  present 

moment,   and  has  achieved  his  task   in  a   manner 

which  cannot  but  redound   to  his  credit. — British 

American  Journal,  Oct.  1861. 

We  believe  this  treatise  will  come  to  be  regarded 

as  high  authority  in  this  branch  of  medical  practice, 

and  we  cordially  commend  it  to  the  favorable  notice 

of  our  brethren  in  the  profession.    For  our  own  part, 

we  candidly  confess  that  we  have  received  many 

new  ideas  from  its  perusal ,  as  well  as  modified  many 

views  which  we  have  long,  and,  as  we  now  think. 

erroneously  entertained  on  the  subject  of  syphilis. 


To  sum  up  all  in  a  few  words,  this  book  laone  which 
no  practising  physician  or  medical  student  can  very 
well  afford  to  do  without. — American  Med  Times, 
Nov.  2,  1801. 

The  whole  work  presents  a  cfimplete  history  of 
venereal  diseases,  comprising  mu"h  interesting  and 
valuable  material  that  has  been  spread  through  med- 
ical journals  within  the  last  twenty  years — the  pe- 
riod of  many  experiments  and  investigations  on  the 
subject — the  whole  carefully  digested  by  the  old  of 
the  author's  extensive  personal  experience,  and 
offeied  to  the  profession  in  an  admirable  form.  Its 
completeness  is  secured  by  good  plates.,  which  are 
especially  full  in  the  anatomy  of  the  genital  organs. 
We  have  examined  it  with  great  satisfaction,  and 
congratulate  the  medical  profession  in  America  on 
the  nationality  of  a  work  that  may  fairly  he  called 
original. — Berkshire  Med.  Journal,  Dec.  Ib6l. 

One  thing,  however,  we  are  impelled  to  say,  that 
we  have  met  with  no  other  book  on  syphilis,  in  the 
English  language,  which  gave  so  full,  clear,  and 
impartial  views  of  the  important  subjects  on  wiiich 
it  treats.  We  cannot,  however,  refrain  from  ex- 
pressing our  satisfaction  with  the  full  and  perspicu- 
ous manner  in  which  the  subject  has  been  presented, 
and  the  careful  attention  to  minute  details,  so  use- 
ful— not  to  say  indispensable — in  a  practical  ireatise. 
In  conclusion,  if  we  may  be  pardoned  the  use  of  a 
phrase  now  become  stereotyped,  but  which  w^e  here 
employ  in  all  seriousness  and  sincerity,  we  do  not 
hesitate  to  express  the  opinion  that  Dr.  Bumstead'a 
Treatise  on  Venereal  Diseases  is  a  "  work  without 
which  no  medical  library  will  hereafter  be  consi- 
dered complete." — Boston  Med.  and  Surg.  Journal 
Sept.  5,  1861. 


BARCLAY  (A.  W.),  M.  D., 

Assistant  Physician  to  St.  George's  Hospital,  &C. 

A  MANUAL  OF  MEDICAL  DIAGNOSIS;   being  an  Analysis  of  the  Signs 

and  Symptoms  of  Disease.     Third  American  from  the  second  and  revised  London  edition.     In 

one  neat  octavo  volume,  extra  cloth,  of  451  pages.     $3  50. 

The  demand  for  another  edition  of  this  work  *hows  that  the  vacancy  which  it  attempts  to  sup- 
ply has  been  recognized  by  the  profession,  and  that  the  eflbrts  of  the  author  to  meet  the  want  have 
been  successful.  The  revision  which  it  has  enjoyed  will  render  it  better  adapted  than  before  to 
afford  assistance  to  the  learner  in  the  prosecution  of  his  studies,  and  to  the  practitioner  who  requires 
a  convenient  and  accessible  manual  for  speedy  reference  in  the  exigencies  of  his  daily  duties.  For 
this  latter  purpose  its  complete  and  extensive  Index  renders  it  especially  valuable,  ofleriug  facilities 
for  immediately  turning  to  any  class  of  symptoms,  or  any  variety  of  disease. 


The  task  of  composing  such  a  work  is  neither  an 
easy  nor  a  light  one;  but  Dr.  Barclay  has  performed 
it  in  a  manner  which  meets  our  most  unqualified 
approbation.  He  is  no  mere  theorist;  he  knows  his 
work  thoroughly,  and  in  attempting  to  perform  it, 
hasnot  exceeded  his  powers. — British  Med.  Journal . 

We  venture  to  predict  that  the  work  will  be  de- 
servedly popular,  and  soon  become,  like  Watson'e 
Practice,  an  indispensable  necessity  to  the  practi- 
tioner.— N.  A.  Med.  Journal. 

An  inestimable  work  of  reference  for  the  young 
practitioner  and  student. — Nashville  Med.  Journal . 


We  hope  the  volume  will  have  an  extensive  cir- 
culation, not  among  students  of  medicine  only,  but 
practitioners  also.  They  will  never  regret  a  faith- 
ful study  of  itspages. — Cincinnati  Lancet. 

An  important  acquisition  to  medical  literature. 
It  is  a  work  of  high  merit,  both  from  the  vast  im- 
portance of  the  subject  upon  which  it  treats,  and 
also  from  the  real  ability  displayed  in  'ts  elabora- 
tion. In  conclusion,  let  us  bespeak  for  this  volume 
that  attention  of  every  student  of  our  art  whieli  it 
so  richly  deserves  —  that  place  in  evsry  medical 
library  which  it  can  so  well  adorn.-  Pininsular 
Medical  Journal. 


BARTLETT  (ELISHA),  M.  D. 
THE  HISTORY,  DIAGNOSIS,  AND  TREATMENT  OF  THE  FEVERS 

OF  THE  UNITED  STATES.  A  new  and  revised  edition.  By  Alonzo  Clark  ,  M.  D.,  Prof. 
of  Pathology  and  Practical  Medicine  in  the  N.  Y.  College  of  Physicians  and  Surgeons,  &c.  la 
one  octavo  volume,  of  six  hundred  pages,  extra  cloth.    Price  $4  25. 

BROWN    (ISAAC    BAKER), 

Surgeon- Accoucheur  to  St.  Mary's  Hospital,  ic. 

ON  SOME  DISEASES  OF  WOMEiN  ADMITTING  OF  SURGICAL  TREAT- 

M.ENT.     With  handsome  illustrations.     One  vol.  Svo.,  extra  cloth,  pp.  276.     $160. 

Mr.  Brown  has  earned  for  himself  a  nigh  reputa- 1  and  merit  the  careful  attention  of  every  aarKeoo- 
tion  in  the  operative  treatment  of  sundry  diseases  accoucheur. — Association  Journal. 
and  injuries  to  which  females  are  peculiarly  subject. 
We  can  truly  say  of  his  work  that  it  is  an  important 
addition  to  obstetrical  literature.  The  operative 
suggestions  and  contrivances  which  Mr.  Brown  de- 
scribes, exhibit  much  practical  sagacity  and  skill, 


We  have  no  hesitation  in  recommending  this  book 
to  t;ie  careful  attention  of  all  surgeons  who  make 
female  complaints  a  part  of  their  atudy  and  practice. 
—Dublin  Qvarterlj/  Journal. 


HENRY  C.   LEA'S   MEDICAL 


BRANDE  (WM.  T.)  D.  C. 
Of  iier  Majfesty's  Mint,  &c. 


AND  ALFRED  S.  TAYLOR,  M .  D.,  F.  R.  S. 

Professor  of  Chemistry  and  Medical  Jurisprudence  in 
Guy's  Hospital. 


CHEMISTRY.     In  one  handsome  8vo.  volume  of  696  pages,  extra  cloth.    $4  50. 

"  Having-  been  engaged  in  teaching-  Chemistry  in  this  Metropolis,  the  one  for  a  period  of  forty, 
and  the  other  for  a  period  of  thirty  years,  it  has  appeared  to  us  that,  in  spite  of  the  number  of  books 
already  exi>tiiig,  there  -was  room  for  an  additional  volume,  which  should  be  especially  adapted  for 
the  use  of  students.  In  preparing  such  a  volume  tor  the  press,  we  have  endeavored  to  bear  in 
mind,  that  the  student  in  the  present  day  lias  much  to  learn,  and  but  a  short  time  at  his  disposal  for 
the  acquisition  of  this  learning." — Authors'  Preface. 

In  reprinting  this  volume,  its  passsge  through  the  press  has  been  superintended  by  a  competent 
chemist,  who  has  sedulously  endeavored  to  secure  the  accuracy  so  necessary  in  a  work  of  this 
nature.  No  notes  or  additions  have  been  introduced,  but  the  publishers  have  been  favored  by  the 
authors  with  some  corrections  and  revisions  of  the  first  twenty-one  chapters,  which  have  been  duly 
inserted. 

In  so  progressive  a  science  as  Chemistry,  the  latest  work  always  has  the  advantage  of  presenting 
the  subject  as  modified  by  the  results  of  the  latest  investigations  and  discoveries.  That  this  advan- 
tage has  been  made  the  most  of,  and  that  the  work  possesses  superior  attractions  arising  from  its 
clearness,  simplicity  of  style,  and  lucid  arrangement,  are  manifested  by  the  unanimous  testimony 
of  the  English  medical  press. 


It  needs  no  great  sagacity  to  foretell  that  this  book 
will  be,  literally,  the  Handbook  in  Chemistry  of  the 
student  and  practitioner.  For  clearness  of  language, 
accuracy  of  description,  extent  of  information,  and 
freedom  from  pedantry  and  mysticism  of  modern 
cliemistry,  no  other  text-hook  comes  into  competition 
■with  it.  The  result  is  a  work  which  for  fulness  of 
matter,  for  lucidity  of  arrangement,  for  clearness  of 
style,  is  as  yet  without  a  rival.  And  long  will  it  be 
without  a  rival.  For,  although  with  the  necessary 
advance  of  chemical  knowledge  addenda  will  be  re- 
quired, there  will  be  little  to  take  away.  The  funda- 
mental excellences  of  the  book  will  remain,  preserv- 
ing it  for  years  to  come,  what  it  now  is,  the  best  guide 
to  the  study  of  Chemistry  yet  given  to  the  world. — 
London  Lancet,  Dec.  20,  1862. 

Most  assuredly,  time  has  not  abated  one  whit  of  the 
fluency,  the  vigor,  and  the  clearness  with  which  they 
not  only  have  composed  the  work  before  us,  but  have, 
60  to  say,  cleared  the  ground  for  it,  by  hitting  right 


and  left  at  the  affectation,  mysticism,  and  obscurity 
which  pervade  some  late  chemical  treatises.  Thus 
conceived,  and  worked  out  in  the  most  sturdy,  com- 
mon sense  method,  this  book  gives,  in  the  clearest  and 
most  summary  method  possible,  all  the  facts  and  doc- 
trines of  chemistry,  with  more  especial  reference  to 
the  wants  of  the  medical  student. — London  Medical 
Times  and  Ga.zttte,  Kov.  29,  1S62. 

If  we  are  not  very  much  mistaken,  this  book  will 
occupy  a  place  which  none  has  hitherto  held  among 
chemists  ;  for,  by  avoiding  the  errors  of  previous  au- 
thors, we  have  a  work  which,  for  its  size,  is  certainly 
the  most  perfect  of  any  in  the  English  language. 
There  are  several  points  to  be  noted  in  this  volume 
which  separate  it  widely  from  any  of  its  compeers — 
its  wide  a])plication,  not  to  the  medical  student  only, 
nor  to  the  student  in  chemistry  merely,  but  to  every 
branch  of  science,  art,  or  commerce  which  is  in  auy 
way  connected  with  the  domain  of  chemistry. — Lon- 
donMed.  Review,  Feb.  1SG3. 


BARWELL  (RICHARD,)   F*  R.  C.  S., 

Assistant  Surgeon  Charing  Cross  Hospital,  tec. 

A  TREATISE  ON  DISEASES  OF  THE  J  JINTS.     Illustrated  with  engrav- 

ings  on  wood.     In  one  very  handsome  octavo  volume,  of  about  500  pages,  extra  cloth ;  $.5  00. 

inp;  and  faithful   delineations  of  distase. — London 


At  the  outset  we  may  state  that  the  work  is 
worthy  of  much  praise,  and  bears  evidence  of  much 
thoughtful  and  careful  inquiry,  and  here  and  there 
of  no  slight  originality.  We  have  already  carritd 
this  notice  further  than  we  intended  to  do,  but  not 
ti'  the  extent  the  work  deserves.  We  can  only  add, 
that  tlie  perusal  of  it  has  afforded  us  great  pleasure. 
The  author  has  evidently  worked  very  hard  at  his 
subject,  and  his  investigations  into  the  Physiology 
and  Pathology  of  Joints  have  been  carried  on  in  a 
manner  which  entitles  hiui  to  be  listened  to  with 
attention  and  respect.  We  must  not  omit  to  men- 
tion the  very  admirable  plates  with  which  the  vo- 
lume isenriched.    We  seldom  meet  with  sueli  strik- 


Med.  Ti7nes  and  Gazette,  Feb.  9,  1801. 

This  volume  will  be  welcomed,  as  the  record  of 
much  honest  research  and  careful  investigation  into 
the  nature  and  treatment  of  a  most  important  class 
of  disorders.  We  cannot  conclude  this  notice  of  a 
valuable  and  ustful  book  without  calling  attention 
to  the  amount  of  6o?mji'/e  work  it  contains.  It  is  no 
slight  matter  for  a  volume  to  show  laborious  inves- 
tigation, and  at  tlie  same  time  original  thought,  on 
the  part  of  its  author,  whom  w  e  may  congratulate 
on  the  successful  completion  of  his  arduous  task. — 
London  Lancet,  March  9,  IStil. 


CARPENTER  (WILLIAM    B.),  M.  D.,  F.  R.  S,,  Sec, 

Examiner  in  Physiology  and  Comparative  Anatomy  in  the  University  of  London. 

THE  MICROSCOPE  AND  ITS  REVELATIONS.  With  an  Appendix  con- 
taining the  Applications  of  the  Microscope  to  Clinical  Medicine,  &c.  By  F.  G.  Siwith,  M.  D. 
Illustrated  by  four  hundred  and  thirty-four  beautiful  engravings  on  wood.  In  one  large  and  very 
handsome  octavo  volume,  of  724  pages,  extra  cloth,  $0  2C). 

The  great  importance  of  the  microscope  as  a  means  of  diagnosis,  and  the  number  of  microsco- 
pists  who  are  also  physicians,  have  induced  the  American  publishers,  with  the  author's  approval,  to 
add  an  Appendix,  carefully  prepared  by  Professor  Siuith,  on  the  applications  of  tne  instrument  to 
clinical  medicine,  together  with  an  account  of  American  Microscopes,  their  modifications  and 
accessories.  This  portion  of  the  work  is  illustrated  with  nearly  one  hundred  wood-cuts,  and,  it  ia 
hoped,  will  adapt  the  volume  more  particularly  to  the  u.se  of  the  American  student. 

The  additions  by  Prof.  Smith  give  it  a  positive 
claim  upon  the  profession,  for  which  we  doubt  not 
he  will  receive  their  sincere  thanks.  Indeed,  we 
know  not  wliere  the  student  of  medicine  will  find 
Buchacomplete  and  satisfactory  collection  of  micro- 


ThoBC  who  are  acquainted  with  Dr.  Carpenter's 
previous  writings  on  Animal  and  Vegetable  Physio- 
lofry,  willfully  understand  how  vasta  store  of  know- 
ledge he  is  able  to  bring  to  bear  upon  so  comprelien- 
«ive  a  subject  as  the  revelations  of  the  microscope ; 
und  even  those  who  have  no  pievitms  acquaintance 
with  the  construction  or  uses  of  this  instruuient, 
will  find  abundance  of  information  conveyed  in  clear 
uid   simple  laiiguajre. — Med     Times  ana   (iazellt. 


seopic  facts  bearing  upon  physiology  and  practical 
medicine  as  is  contained  in  Prof.  Smith 'e  appendix; 
and  this  of  itself,  it  seems  to  us,  is  fully  worth  the 
cost  of  tlic  volume. — Louiiviile  Medico,  Revietr, 


AND    SCIENTIFIC    PUBLICATIONS. 


CARPENTER  (WILLIAM   8.),   M.  O.,  F.  R.  S., 

Examiner  in  PliyBiology  and  Oonipunitive  Anatomy  in  the  University  of  London. 

FlilNCIPLES  OF  HUMAN  PHYSIOLOGY;  with  their  chief  applicationB  to 

Psychology,  Pathology,  TherapKiilics,  Hygiene,  and  Foroii.-i*'  Medicine.  A  new  American,  from 
the  last  and  revised  London  ediliori.  Wiih  nearly  three  hundred  illuslrations.  Edited,  with  addi- 
tions, by  Francis  Giirney  S.mith,  M.  D.,  Professor  olthe  Iiisliiiites  of  Medicine  in  the  Pennsyl- 
vania Medical  College,  &c.  In  one  very  large  and  beautil'ul octavo  volume, ol  about  nine  hundred 
large  pages,  handsomely  printed,  extra  cloth,  $5  50 

For  upwards  of  tliirteen  years  Dr.  Carpcnior's  i  To  eulogize  thispreat  work  would  be  Buperfluous. 
work  has  been  considered  by  the  profession  gene-  j  We  should  observe,  iiowever,  that  in  this  edition 
rally,  both  in  this  country  and  Kngiand,  as  the  most  the  author  has  remodelled  a  large  portion  of  tha 
valuable  compendium  on  the  subject  of  physiology  ,  former,  and  the  editor  has  added  much  matter  of  in- 
inour  language.  This  distinction  it  owes  to  the  high  ;  terest,  especially  in  the  form  of  illustrations.  We 
attainments  and  unwearied  industry  of  its  aceom- j  may  ecmfidently  recommend  it  as  the  most  complete 


plished  author.  Thepresenteditiim  (whicli,like  the 
last  American  one,  was  prepared  by  the  author  him- 
self), is  the  result  of  such  extensive  revision,  that  it 
may  almost  be  considered  a  new  work.  We  need 
hardly  say,  in  concluding  this  briefnotice,  that  while 
the  work  is  indispensable  to  every  student  of  medi- 
cine in  this  country,  it  will  amply  repay  the  practi- 
tioner for  its  perusal  by  the  interest  and  value  of  its 
c  intents. — Boston  Med.  and  Surg.  Journal. 

This  is  a  standard  work — the  text-book  used  by  all 
medical  students  who  read  the  English  language. 
(t  has  passed  through  several  editions  in  order  to 
keep  pace  with  the  rapidly  growing  science  of  Phy- 
siology.    Nothing  need  be  said  in  its  praise,  for  its 


work   on   Human    Physiology   in  our    language. — 
Southern  Med.  and  Surg.  Journal. 

Ttie  most  complete  work  on  the  science  in  our 
language. — Am.  Med.  Journal. 

The  most  complete  work  now  extant  in  our  lan- 
guage.— N.  O.  Med.  Register. 

The  best  text-book  in  the  language  on  this  ex 
tensive  subject. — London  Med.  Times. 

A  complete  cyclopaedia  of  this  branch  of  scienca. 
—N.  Y.  Med.  Times. 

The  profession  of  this  country,  and  perhaps  also 
of  Europe,  have  anxiously  and  for  some  time  awaited 
the  announcement  of  this  new  edition  of  Carpenter's 


merits  are  universally  known  J  we  have  nothing  to    Human  Physiology.    His  former  editions  have  for 
say  of  its  defects,  for  tliey  only  appear  where  the  i  many  years  been  almost  the  only  text-book  on  Phy 


science  of  which  it  treats  is  incomplete. — Western 
Lancet. 

The  most  complete  exposition  of  physiology  which 
any  language  can  at  present  give. — Brit,  and  For. 
M.ed.-Ckirurg.  Revieva. 

The  greatest,  the  most  reliable,  and  the  best  book 


Biology  in  all  our  medical  schools,  and  its  circula- 
tion among;  the  profession  has  been  unsurpassed  by 
any  work  in  any  department  of  medical  scienj;;e. 

It  is  quite  unnecessary  for  us  to   speak    of  this 
work  as  its  merits  would  justify.    The  mere  an- 
nouncement of  its  appearance  will  afford  the  highest 
pleasure  to  every  student  of  Physiology,  while  ito 
OQ  the^subject  which  we  know  of  in  the  English  j  perusal  will  be  of   infinite   service  in    advancing 
language. — Stethoscop*.  '  physiologicalscience. — Ohio  Med.andSurg.  JoKr». 


BY   THE  SAME   AUTHOR. 

ELEMENTS  (OR  MANUAL)  OF  PHYSIOLOGY,  INCLUDING  PHYSIO- 

LOGICAL  ANATOMY.     Second  American,  from  a  new  and  revised  London  edition.     With 

one  hundred  and  ninety  illustrations.    In  one  very  handsome  octavo  volume,  leather,     pp.  566. 

$4  00. 

In  publishing  the  first  edition  of  this  work,  its  title  was  altered  from  that  of  the  London  volume, 
by  the  substitution  of  the  word  "  Elements"  for  that  of  "  Manual,"  and  with  the  author's  sanction 
Jhe  title  of  "  Elements"  is  still  retained  as  being  more  expressive  of  the  scope  of  the  treatise. 

BY  THE   SAME   AUTHOR. 

PRINCIPLES  OF  COMPARATIVE   PHYSIOLOGY.     New  American,  from 

the  Fourth  and  Revised  London  edition.     In  one  large  and  handsome  octavo  volume,  with  over 
three  hundred  beautiful  illustrations,     pp.  752.     Extra  cloth,  $5  00. 

This  book  should  not  only  be  read  but  thoroughly  i  no  man,  we  believe,  could  have  brought  to  so  sue 


Bcudied  by  every  member  of  the  profession.  None 
are  too  wise  or  old,  to  be  benefited  thereby.  But 
espeotally  to  the  younger  class  would  we  cordially 
commend  it  as  best  fitted  of  any  work  in  the  English 
language  to  qualify  them  for  the  reception  and  coin- 
prehension  of  those  truths  which  are  daily  being  de- 
veloped in  physiology. — Medical  Counsellor. 

Without  pretending  to  it,  it  is  an  encyclopedia  of 
the  subject,  accurate  and  complete  in  all  respects — 
a  truthful  reflection  of  the  advanced  state  at  which 
the  science  has  now  arrived. — Dublin  Quarterly 
Journal  of  Medical  Science. 

A  truly  magnificent  work — in  itself  a  perfect  phy- 
Biological  study. — RuTiking^s  Abstract. 

This  work  stands  without  its  fellow.  It  is  one 
few  men  in  Europe  could  have  undertaken;  it  is  one 


cessful  an  issue  as  Dr.  Carpenter,  ft  required  for 
its  production  a  physiologist  at  once  deeply  read  in 
the  labors  of  others,  capable  of  taking  a  general, 
critical,  and  unprejudiced  view  of  those  labors,  ana 
of  coml)ining  the  varied,  heterogeneous  materials  at 
his  disposal,  so  as  to  form  an  harmouious  whole. 
We  feel  that  this  abstract  can  give  the  reader  a  very 
imperfect  idea  of  the  fulness  of  this  work,  and  no 
idea  of  its  unity,  of  the  admirable  mai  ner  in  which 
material  has  been  brought,  from  the  most  various 
sources,  to  conduce  to  its  eonipletenesi ,  of  the  lucid- 
ity of  the  reasoning  it  contains,  or  of  the  clearnesB 
of  language  in  which  the  whole  is  clothed.  Not  ihe 
profession  only,  but  the  scientific  world  at  large, 
must  feel  deeply  indebted  to  Dr.  Carpenter  for  thi« 
great  work.  It  must,  indeed,  add  largely  even  to 
his  high  reputation. — AUdieal  Tim$i. 


BY  THE  SAME  AUTHOR.     (Prepari7ig.) 

PRINCIPLES  OF   GENERAL   PHYSIOLOGY,    INCLUDING    ORGANIC 

CHEMISTRY  AND   HISTOLOGY.     With   a  General  Sketch  ol   the  Vegetable  and  Animal 
Kingdom.     In  one  large  and  very  handsome  octavo  volume,  with  several  hundred  illustraiioni. 

BY   THE   SAME   AITTHOE. 

A  PRIZE  ESSAY  ON  THE  USE  OF  ALCOHOLIC  LIQUORS  IN  HEALTH 

AND  DISEASE.     New  edition,  with  a  Preface  by  D.  F.  Condie,  M.  D.,  and  eiplunatUD^  ol 
•cientilic  words.    In  oae  neat  12mo.  volume,  extra  cloth     pp.  178.     60  ceats. 


8 


HENRY  C.    LEA'S   MEDICAL 


CONDIE  (D.  F."),  M.  D.,  ice. 
A  PRACTICAL  TREATISE  ON  THE  DISEASES  OF  CHILDREN.    Fifth 

edition,  revised  and  augmented.  In  one  large  volume,  8vo.,  extra  cloth,  of'over  750  pages.  f4  50. 
In  presenting  a  new  and  revised  edition  ol  this  favorite  work,  the  publishers  have  only  to  state 
that  the  author  has  endeavored  to  render  it  in  every  respect  "a  complete  and  faithful  exposition  of 
the  pathology  and  therapeutics  of  the  maladies  incident  to  the  earlier  stages  of  existence — a  full 
and  exact  account  of  the  diseases  of  infancy  and  childhood."  To  accomplish  this  he  has  subjected 
the  whole  work  to  a  careful  and  thorough  revisi-^n,  rewriting  a  considerable  portion,  and  adding 
several  new  chapters.  In  this  manner  it  is  hoped  that  any  deficiencies  which  may  have  previously 
existed  have  been  supplied,  that  the  recent  labors  of  practitioners  and  observers  have  been  tho- 
roughly incorporated,  and  that  in  every  point  the  work  will  be  found  to  maintain  the  high  reputation 
it  has  enjoyed  as  a  complete  and  thoroughly  practical  book  of  reference  in  infantile  afl'ections. 
A  few  notices  of  previous  editions  are  subjoined. 

We  pronounced  the  first  edition  to  be  the  beel 
work  on  the  diseases  of  children  in  the  English 
language,  and,  notwithstanding  all  that  has  been 
published,  we  still  regard  it  in  that  light. — Medical 
Examiner. 


Dr.  Condie's  scholarship,  acumen,  industry,  and 
practical  sense  are  manifested  in  this,  as  in  all  his 
numerous  contributions  to  science. — Dr.  Holmes's 
Report  to  the  American  Medical  Association. 

Taken  as  a  whole,  in  our  judgment,  Dr.  Condie's 
Treatise  is  the  one  from  the  perusal  of  which  the 
practitioner  in  this  country  will  rise  with  the  great- 
est satisfaction. — Western  Journal  of  Medicine  and 
Surgery . 

One  of  the  best  works  upon  the  Diseases  of  Chil- 
dren in  the  English  language. — Western  Lancet. 

We  feel  assured  from  actual  experience  that  no 
physician's  library  can  be  complete  without  a  copy 
of  this  work. — A'^.  Y.  Journal  of  Medicine. 

A  veritable  paediatric  encyclopaedia,  and  an  honot 
to  American  medical  literature. — Ohio  Medical  and 
Surgical  Journal. 

We  feel  persuaded  that  the  American  medical  pro- 
fesskm  will  soon  regard  it  not  only  as  a  very  good, 
but  as  the  very  best  "Practical  Treatise  on  the 
Diseases  of  Children." — ATnerican  MedicalJournal 

In  the  department  of  infantile  therapeutics,  the 
work  of  Dr.  Condie  is  considered  one  ot  the  tiest 
which  has  been  published  in  the  English  language. 
— The  Stethoscope. 


The  value  of  works  by  native  authors  on  the  dis- 
eases which  the  physician  is  called  upon  to  combat, 
will  be  appreciated  by  all ;  and  the  work  of  Dr.  Con- 
die  has  gained  for  itself  the  character  of  a  safe  guide 
for  students,  and  a  useful  work  for  consuftation  by 
those  engaged  in  practice. — N.  Y.  Med   Times. 

This  is  the  fourth  edition  of  this  deservedly  popu- 
lar treatise.  During  the  interval  since  the  last  edi- 
tion, it  has  been  subjected  to  a  thorough  revision 
by  the  author;  and  all  new  observations  in  the 
pathology  and  therapeutics  of  children  have  been 
included  in  the  present  volume.  As  we  said  btfore, 
we  do  not  know  of  a  better  book  on  diseases  of  chil- 
dren, and  to  a  large  part  of  its  recommendations  wa 
yield  an  unhesitating  concurrence.— B«#o/o  Med. 
Journal. 

Perhaps  the  mostfull  and  complete  work  now  be- 
fore the  profession  of  the  United  States;  indeed,  we 
may  say  in  the  English  language.  It  is  vastly  supe- 
rior to  mostof  its  predecessors.— jTransjfZ'uanioilledl. 
Journal 


CHRISTISON  (ROBERT),  M .  D.,  V.  P.  R.  S.  E.,  See. 
A  DISPENSATORY;  or.  Commentary  on  the  Pharmacopujias  of  Great  Britain 

and  the  United  States;  comprising  the  Natural  History,  Description,  Chemistry,  Pharmacy,  Ac- 
tions, Uses,  and  Doses,  of  the  Articles  of  tiie  Materia  Medica.  Second  edition,  revised  and  im- 
proved, with  a  Supplement  containing  the  most  important  New  Remedies.  With  copious  .Addi- 
tions, and  two  hundred  and  thirteen  large  wood-engravings.  By  R.  Eglesfeld  Grifflt-H;,  M.  D. 
In  one  very  large  and  handsome  octavo  volume,  extra  cloth,  of  over  1000  pages.   $4  CO 


COOPER  (BRANSBY   BJ,  F.  R.  S. 

LECTURES  ON  THE  PRINCIPLES  AND   PRACTICE  OF   SURGERY- 

In  one  very  large  octavo  volume,  extra  cloth,  of  750  pages,    $2  00. 


COOPER  ON  THE  ANATOMY  AND  DISKASES 
OF  THE  BREAST,  with  twenty-five  Miscellane- 
ous and  Surgical  Papers.  One  large  volume,  im- 
perial bvo.,  extra  cloth,  with  252  figures,  on  36 
plates.     S3  00. 

COOPER  ON  THE  STRUCTURE  AND  DIS- 
EASES OF  THE  TESTIS,  AND  ON  THE 
THYMUS  GLAND.  One  vol.  imperial  Bvo. ,  ex- 
tra cloth,  with  177  ligures  on  29  plates.    $2  50. 


CLYMER  ON  FEVERS;  THEIR  DIAGNOSIS} 
PATHOLOGY,   AND    TREATMENT.     In   ona 

octavo  volume,  leather,  of  600  pages.  $1  75. 
COJ-OMBaT  DE  L'lSERE  ON  THE  DISEASES 
OF  FEMALl-ye,  and  on  the  special  Hygiene  of 
their  Sex.  Translated,  with  many  Notes  and  Ad- 
ditions, by  C.  D.  Meigs,  M.  D.  Second  edition, 
revised  and  improved  In  one  large  volume,  oc- 
tavo, leather,  with  numerous  wood-cutB.  pp.  720. 
»3  75. 


CARSON  (JOSEPH),  M.  D., 
ProfesBOr  of  Materia  Medica  and  Pharmacy  in  the  University  of  Pennsylvania 

SYNOPSIS  OF  THE  COURSE  OP  LECTURES  ON  MATERIA  MEDIOA 

AND  PHARMACY,  delivered  in  the  University  of  Pennfcylvania 
the  Modus  Operandi  of  Medicines.     Third  edition,  revised. 
%2  50. 


Wiih  three  Lectures 
In  one  handsome  octavo  volume. 


CURLING    (T.    B.),    F.R.S., 

Surgeon  to  the  London  Hospital,  President  of  the  Hunterian  Society ,  &a. 

A  PRACTICAL  TREATISE  ON  DISEASES  OF  THE  TESTIS,  SPERMA- 

TIC  CORD,  AND  SCROTUM.    Second  American,  from  the  second  and  enlarged  English  edi- 
Hon.    iu  one  huadsume  octavo  volume,  extra  cloth,  with  numeruubiilustralioas.  pp.  420.  $2  00 


AND    SCIENTIFIC   PUBLICATIONS. 


CHURCHILL  (FLEETWOOD),  M.  D.,  M.  R.  I.  A. 
ON  THE  THEORY  AND  PRACTICE  OF  MIDWIFERY.     A  new  American 

from  the  fourth  revised  and  enlarged  London  edition.  With  Notes  and  Additions,  by  D.  Francis 
CoNDiE,  M.  D.,  author  of  a  "Practical  Treati»<e  on  the  Di.seases  of  Children,"  &c.  With  194 
illuKtrations.  In  one  very  handsiome  octavo  volume,  ofnearly  700  large  pages,  extra  clolh,  $4  00. 
This  work  has  been  so  long  an  established  favorite,  both  as  a  text-book  for  the  learner  and  an  a 
reliable  aid  in  consultation  lor  the  practitioner,  that  in  presenting  a  new  edition  it  is  only  necessary 
to  call  attention  to  the  very  extended  improvements  which  it  has  received.  Having  had  the  benefit 
of  two  revisions  by  the  author  since  the  last  American  reprint,  it  has  been  materially  enlarged,  and 
Dr.  Churchill's  well-known  conscientu»us  mdustry  is  a  guarantee  that  every  portion  has  been  tho- 
roughly brought  up  with  the  latest  results  of  European  iuvestigation  in  all  departments  of  the  sci- 
ence and  art  of  obstetrics.  The  recent  date  of  the  last  Dublin  edition  has  not  left  much  of  novelty 
for  the  American  editor  to  introduce,  but  he  has  endeavored  to  insert  whatever  has  since  appearecl, 
together  with  such  matters  as  his  experience  has  shown  him  would  be  desirable  for  the  American 
student,  including  a  large  number  of  illustrations  Wiih  the  sanction  of  the  author  he  has  added 
in  the  form  of  an  appendix,  some  chapters  from  a  little  "Manual  for  Mid  wive.-  and  Nurses,"  re- 
cently issued  by  Dr.  Churchill,  believing  that  the  details  there  presented  can  hardly  fail  to  prove  ot 
advantage  to  the  junior  practitioner.  The  result  of  all  these  auditions  is  that  the  work  now  con- 
tains fully  one-half  more  matter  than  the  last  American  edition,  with  nearly  one-half  more  illus- 
trations, so  that  notwithstandhig  the  use  of  a  smaller  type,  the  volume  contains  almost  two  hundred 
pages  more  than  before. 

No  effort  has  been  spared  to  secure  an  improvement  in  the  mechanical  execution  of  the  work 
equal  to  that  which  the  text  has  received,  and  the  volume  is  confidently  presented  as  one  of  the^ 
handsomest  that  has  thus  far  been  laid  before  the  American  profession;  while  the  verv  low  price 
at  which  it  is  offered  should  secure  for  it  a, place  in  every  lecture-room  and  on  every  office  table. 


A  better  book  in  which  to  learn  these  important 
points  we  have  not  met  than  Dr.  Churchill's.  Every 
page  of  it  is  full  of  instruction;  the  opinion  of  all 
v/nters  of  authority  is  given  on  questions  of  diffi- 
culty, as  well  as  the  directions  and  advice  of  the 
learned  autuor  himself,  to  which  tie  adds  the  result 
of  statistical  inquiry,  putting  statistics  in  their  pro 
per  place  and  giving  them  their  due  weight,  and  no 
raore.  We  have  never  read  a  book  more  free  from 
professional  jealousy  than  Dr.  Churchill's.  It  ap- 
pears to  be  written  w^ith  the  truedesignof  abook  on 
medicine,  viz :  to  give  all  that  is  known  on  the  sub- 
ject of  which  he  tVeats,  both  theoretically  and  prac- 
tically, and  to  advance  such  opinions  of  his  own  as 
he  believes  will  benefit  medical  science,  and  insure 
the  safety  of  the  patient.  We  have  said  enough  to 
convey  to  the  profession  that  this  book  of  Dr.  Chur- 
ehill'e  is  admirably  suited  for  a  book  of  reference 
for  the  practitioner,  as  well  as  a  text-book  for  the 
atudent,  and  we  hope  it  may  be  extensively  pur- 
chased amongst  our  readers.  To  them  we  most 
strongly  recommend  it. —  Dublin  Medical   Press. 

To  bestow  praise  on  a  book  that  has  received  such 
marked  approbation  would  be  superfluous.  We  need 
only  say,  therefore,  that  if  the  first  edition  was 
thought  worthy  of  a  favorable  reception  by  the 
medical  public,  we  can  confidently  affirm  that  this 
virill  be  found  much  more  so.  The  lecturer,  the 
practitioner,  and  the  student,  may  all  have  recourse 
to  its  pages,  and  derive  from  their  perusal  much  in- 
terest and  instruction  in  everything  relating  to  theo- 
retical and  practical  midwifery. — Dublin  Quarterly 
Journal  of  Medical  Science. 

A  work  of  very  great  merit,  and  such  as  we  can 
confidently  recommend  to  the  study  of  every  obste- 
tric practitioner. — London  Medical  Gazette . 

Few  treatises  will  be  found  better  adapted  as  n 
text- book  for  the  student,  or  as  a  manual  for  th< 
frequent  consultation  of  the  young  practitioner. - 
American  Medical  Journal. 


Were  we  reduced  to  the  necessity  of  having  but 
>ne  work  on  midwifery,  and  permitted  to  choose, 
we  would  unhesitatingly  take  Churchill. —  Western 
Med.  and  Surg.  Journal. 

It  is  impossible  to  conceive  a  more  useful  and 
'.legant  manual  than  Dr.  Churchill's  Practice  of 
Vlidwifery. — Provincial  Medical  Journal. 

Certainly,  in  our  opinion,  the  very  best  work  on 
he  subject  which  exists. — N.  Y.  Annalist. 

No  work  holds  a  higher  position,  or  is  more  de- 
serving of  being  placed  in  the  hands  of  the  tyro, 
the  advanced  student,  or  the  practitioner. — Medical 
ExaTniner. 

Previous  editions  have  been  received  with  mark- 
ed favor,  and  they  deserved  it;  but  this,  reprinted 
from  a  very  late  Dublin  edition,  carefully  revised 
and  brought  up  by  the  author  to  the  present  time, 
does  present  an  unusually  accurate  and  able  expo- 
sition of  every  important  particular  embraced  in 
the  departmentof  midwifery.  *  *  The  clearness, 
directness,  and  precision  of  its  teachings,  together 
with  the  great  amount  of  statistical  research  which 
its  text  exhibits,  have  served  to  place  it  already  in 
the  foremost  rank  of  works  in  this  department  of  re- 
medial science. — N.  O.  Med.  and  Surg.  Journal. 

In  our  opinion,  it  forms  one  of  the  best  if  not  the 
very  best  text-book  and  epitome  of  obstetric  scienc« 
which  we  at  f  resent  possess  in  the  English  lan- 
guage.—  Monthly  Journal  of  Medical  Science. 

The  clearness  and  precision  of  style  in  which  it  ia 
written,  and  the  greatainount<.f  statistical  research 
which  it  contains,  have  served  to  place  it  in  the  first 
rankof  works  in  this  departmentof  medical  science. 
—  N.  Y.  Journal  of  Medicine . 

This  is  certainly  the  most  perfect  system  extant. 
It  is  the  best  adapted  for  the  purposes  of  a  text- 
jook,  and  that  which  he  whose  necessities  confine 
"liTi  to  one  book,  should  select  in  preference  to  all 
others. — Soutkern  Medical  and  Surgical  Journal. 


BY   THE   SAME  AUTHOR. 

ON  THE  DISEASES  OF  INFANTS   AND  CHILDREN.     Second  American 

Edition,  revised  and  enlarged  by  the  author.    Edited,  with  Notes,  by  W.  V.  Keating,  M.  D.    In 

one  large  and  handsome  volume,  extra  cloth,  of  over  700  pages.    $4  50. 

In  preparing  this  work  a  second  time  for  the  American  profession,  the  author  has  spared  no 
labor  in  giving  it  a  very  thorough  revision,  introducing  several  new  chapters,  and  rewriting  others, 
while  every  portion  of  the  volume  has  been  subjected  to  a  severe  scrutiny.  The  efforts  of  the 
American  editor  have  been  directed  to  supplying  such  information  relative  to  matters  peculiar 
to  this  country  as  might  have  escaped  the  attention  of  the  author,  and  the  whole  may,  there- 
fore, be  safely  pronounced  one  of  the  most  complete  works  on  the  subject  accessible  to  the  Ame- 
rican Profession.  By  an  alteration  in  the  size  of  the  page,  these  very  extensive  additions  have 
been  accommodated  without  unduly  increasing  the  size  of  the  work. 

BY  the  same  author. 

ESSAYS  ON  THE  PUERPERAL  FEVER,  AND  OTHER  DISEASES  PE- 
CULIAR TO  WOMEN.  Selected  from  the  writings  ot  British  Authors  previous  to  the  close  ot 
tiie  Eighteenth  Century.    In  one  neat  octavo  volume,  extra  clolh,  of  about  450  pages.    $2  50. 


act  and  comprehensive  expositions  of  tlie  present 
Btate  of  medical  knowledge  in  respect  to  the  diseases 
of  women  f  liat  has  yet  been  published. — Ain.Journ. 
Mfd.  Sciences. 


10  HENRY   C.   LEA'S   MEDICAL 

CHURCHILL  (FLEETWOOD),    M .  D.,  M .  R.  ! .  A.,    &c. 

ON  THE  DISEASES  OF  WOMEN;  including  those  of  Pregnancy  and  Child- 
bed.   A  new  American  edition,  revised  by  the  Author.    With  Notes  and  Additions,  by  D    Fram- 
cis  CoNDiE,  M.  D.,  author  ol  "  A  Practical  Treatise  on  the  Diseases  ofChiidren."    With  nume- 
rous illustrations.     In  one  large  and  handsome  octavo  volume,  extra  cloth,  of  768  pages.    $4  00. 
This  edition  of  Dr.  Churchill's  very  popular  treatise  may  almost  be  termed  a  new  work,  so 
thoroughly  has  he  revised  it  in  every  portion.     It  will  be  found  greatly  enlarged,  and  completely 
brought  up  to  the  most  recent  condition  o(  the  subjecU,  while  the  very  handsome  series  of  illustra- 
tions introduced,  representing  such  pathological  conditions  as  can  be  accurately  portrayed,  present 
a  novel  feature,  and  afford  valuable  as.  isiance  to  the  young  practitioner.     Such  additions  as  ap- 
peared desirable  for  the  American  student  have  been   made  by  the  editor,  Dr.  Condie,  while  a 
marked  improvement  in  the  mechanical  execution  keeps  pace  with  the  advance  in  all  other  respects 
which  the  volume  has  undergone,  while  the  price  has  been  kept  at  the  former  very  moderate  rate. 
It  comprises,  unquestionably,  one  of  the  most  ex-  |  extent  that  Dr.  Churchill  does.     His,  indeed,  is  th« 

only  thorough  treatise  we  know  of  on  the  subject; 
and  it  may  be  commended  to  practitioners  and  stu- 
dents as  a  masterpiece  in  its  particular  dejiartment. 
—  Th)  Western  Journal  of  Medicine  and  Surgery. 
This  work  is  the  most  reliable  which  we  possess  [      Ab  a  comprehensive    manual  for  students,   or   a 
on  this  subject;  and  is  deservedly  popular  with  the  [  work  of  reference  for  practitioners,  it  surpasses  any 
prt'fess'um— Charleston  Med.  Journal,  July,  1857.        other  that  has  ever  issued  on  the  same  subjectfrom 

We  know  of  no  author  who  deserves  that  appro-     the  British  press. — Dublin  Quart.  Journal. 
Ration,  on  "the  diseases  of  females,"  to  the  same  1 

DICKSON   (S.    H.),    M.  D., 

Professor  of  Practice  of  Medicine  in  the  Jefferson  Medical  College,  Philadelphia. 

ELEMENTS  OF  MEDICINE;   a  Compendious  View  of  Pathology  and  Thera- 

peutics,  or  the  History  and  Treatment  of  Diseases.     Second  edition,  revised.    In  one  large  and 

handsome  octavo  volume,  of  750  pages,  extra  cloth.     $4  00. 

The  steady  demand  which  has  so  soon  exhausted  the  first  edition  of  this  work,  sufficiently  shows 
that  the  author  was  not  mistaken  in  supposing  that  a  volume  of  this  character  was  needed — an 
elementary  manual  of  practice,  which  should  present  the  leading  principles  of  medicine  with  the 
practical  results,  in  a  condensed  and  perspicuous  manner.  Disencumbered  of  unnecessary  detail 
and  fruitless  speculations,  it  embodies  what  is  most  requisite  for  the  student  to  learn,  and  at  the 
same  time  what  the  active  practitioner  wants  when  obliged,  in  the  daily  calls  of  his  profession,  to 
refresh  his  memory  on  special  points.  The  clear  and  attractive  style  of  the  author  renders  the 
whole  easy  of  comprehension,  while  his  long  experience  gives  to  his  teachings  an  authority  every- 
where acknowledged.  Few  physicians,  indeed,  have  had  wider  opportunities  for  observation  and 
experience,  and  few,  perhaps,  have  used  them  to  better  purpose  As  the  result  of  a  long  life  de- 
voled  to  study  and  practice,  the  present  edition,  revised  and  brought  up  to  the  date  of  publication, 
will  doubtless  maintain  the  reputation  already  acquired  as  a  condensed  and  convenient  American 
text-book  on  the  Practice  of  Medicine. 


DRUITT   (ROBERT),   M.R.C.S.,   &c. 
THE  PRINCIPLES  AND  PRACTICE  OF  MODERN  SURGERY.     A  new 

and  revised  American  from  the  eighth  enlarged  and  improved  London  edition.     Illustrated  with 

four  hundred  and  thirty-two  wood-engravings.    In  one  very  handsomely  printed  octavo  volume 

of  nearly  700  large  pages,  extra  cloth,  $4  GO. 

A  work  which  like  Druitt's  Surgery  h«s  for  so  many  years  maintained  the  position  of  a  lead- 
ing favorite  with  all  classes  of  the  profession,  needs  no  special  recommendation  to  attract  attention 
to  a  revised  edition.  It  is  only  necessary  to  state  that  the  author  has  spared  no  pains  to  keep  the 
work  up  to  its  well  earned  reputation  of  presenting  in  a  small  and  convenient  compass  the  latest 
condition  of  every  department  of  surgery,  considered  both  as  a  science  and  as  an  art;  and  that  the 
services  of  a  competent  American  editor  have  been  employed  to  introduce  whatever  novelties  may 
have  escaped  the  author's  attention,  or  may  prove  of  service  to  the  American  practitioner.  As 
several  editions  have  appeared  in  London  since  the  issue  of  the  last  American  reprint,  the  voluii^ 
has  had  Ihe  benefit  of  repeated  revisions  by  the  author,  resulting  in  a  very  thorough  alteration  and 
improvement.  The  extent  of  these  additions  may  l)e  estimated  from  the  fact  that  it  now  contains 
about  one-third  more  matter  than  the  previous  American  edition,  and  that  notwithstanding  the 
adoption  of  a  smaller  type,  Ihe  pages  have  been  increased  by  about  one  hundred,  while  nearly  two 
hundred  and  fifty  wood-cuts  have  been  added  to  the  former  list  of  illustrations. 

A  marked  improvement  will  also  be  perceived  in  the  mechanical  and  artistical  execution  of  the 
work,  which,  printed  in  the  l)est  style,  on  new  type,  and  fine  paper,  leaves  little  to  be  desired  as 
reerards  external  finish;  while  at  the  very  low  price  alfixed  it  will  be  found  one  of  the  cheapest 
Volumes  accessible  to  the  profession. 


This  popular  volume,  now  a  most  comprehensive 
work  on  surgery,  has  undergone  many  correcticms, 
improvemeni.s,and  additions,  and  the  principles  and 
tlie  practice  of  the  art  have  been  brought  down  to 
the  latest  record  and  observation.  Of  the  operations 
in  surgery  it  is  impossible  to  speak  too  highly.  The 
deHcripiioDS  are  so  clear  and  concise,  and  the  illus- 
trations 80  accurate  and  numerous,  that  the  student 
can  have  no  difficulty,  with  instrument  in  hand,  and 
bi ok  by  his  side,  over  the  dead  body,  in  ol)tainine; 


nothing  of  real  practical  importance  has  been  omit- 
ted ;  it  presents  a  faithful  epitome  of  everything  re- 
lating t )  surgery  up  to  the  present  hour.  It  is  de- 
servedly a  popular  manual,  both  with  the  student 
and  practitioner. — London  Lancet.  Nov.  19,  IB-W. 

In  closing  this  brief  notice,  we  recommend  as  cor- 
dially as  ever  thi.s  most  useful  and  comprehensive 
hand-book.  It  must  prove  a.  vast  assistance,  not 
only  to  the  student  of  surgery,  but  also  to  the  busy 


i^i.iiK  uy  iilH  Blue,  over  mi-   in-uu    uouy,    iii    \nnu.iiiiiia  '        .  ,  ..  t  .1      i    ■       .„  «..  ,1..,...^^ 

a  proper  knowledge  and  sufficient  tact  in  this  much  pract,  .oner  wli.  may  not  have  he  >f'«»re  t"  ^'^"te 
neglected  deparlmentofmedicaleducation.-/;r,««A  '"'"^j-'f  L^i  tlie  study  "^ '""^«  ""^t' VJ"  "I^"— 
and  Foreign  Medico-Chirurg.  Review,  Jan.  1S60        I  i"«''«"  ^«'^    ^""'''  ""'^  ^-°»e««,  Oct  i2,  18a9. 

In  the  present  edition  the  author  has  entirely  re-  In  a  word,  this  eighth  edition  of  Dr.  Druitt'i 
written  many  of  the  chapters,  and  has  incorporated  !  Manual  of  Surgery  is  all  that  the  surgical  stmlent 
the  various  improvemrnls  anil  adifilions  in  inodern  or  practitioner  eoahl  desire.  —  Ow6/in  Quartirlf 
•urgery.    On  carefully  going  over  it,  we  find  that ;  Journal  of  M»d.  Sciences,  Nov.  1859. 


AND    SCIENTIFIC    PUBLICATIONS. 


n 


DALTON,  JR.  (J.   C),   M.  D. 
Profeesorof  Physiology  in  the  CDllcge  of  I'liysiciuns,  New  York. 

A  TREATISE  ON  HUMAN  PHYSIOLOGY,  designed  for  the  use  of  Studcuts 

and  Practitioners  of  Medicine.  Third  edition,  revised,  with  nearly  three  hundred  illu->trati<>ns 
on  wood.  In  one  very  beautiful  oetavo  volume, of  700  pa-^es,  extra  cloth,  $■)  2^).  (Just  I.s.yued.) 
The  rapid  demand  for  another  edition  of  this  work  sufficiently  shows  that  the  author  has  >,uc- 
ceeded  in  liis  ell'orts  to  produce  a  IcxI-book  of  standard  and  perinanent  value,  embodying;'  wilfiin 
a  moderate  compass  all  that  is  definitely  and  positively  known  within  the  domain  of  Human 
Physiology.  His  high  reputation  as  an  original  observer  and  investigator,  is  a  guarantee  thai  in 
again  revising  it  he  has  introduced  whatever  is  necessary  to  render  it  thoroughly  on  a  level  with 
the  advanced  science  of  the  day,  and  this  has  been  accomplished  without  unduly  increasing  the 
size  of  the  volume. 

No  exertion  has  been  spared  to  maintain  the  hisfh  standard  of  typographical  execution  which  has 
rendered  this  work  admittedly  one  of  the  handsomest  volumes  as  yet  produced  in  this  country. 

It  will  be  seen,  therefore,  that  Dr.  Dalton'a  best '  own  origmHl  views  iinri  experiments,  together  with 
elforts  have  been  directed  towards  perfecting  his  a  desire  to  supply  what  heeoi.sidered  soniedeficien- 
work.  The  additions  are  marked  by  the  same  fea-  '  cies  in  the  first  edition,  have  already  made  the  pre- 
tures  which  characterize  the  remainder  of  the  vol-  \  sent  one  a  necessity,  and  it  will  no  doubt  be  even 
ume,  and  render  it  by  far  the  most  desirable  text-  !  more  eagerly  sought  for  than  tlie  first.  Ttiat  it  is 
book  on  physiology  to  place  in  the  hands  of  the  :  not  merely  a  reprint,  will  be  seen  from  the  author's 
Student  which,  so  far  as  we  are  aware,  exists  in  !  statement  of  the  following  principal  additions  and 
tlie  English  language,  or  perhaps  in  any  other.  We  altera'itms  which  he  has  made.  The  present,  like 
therefore  have  no  hesitation  in  recommending  Dr.  the  first  editicm,  is  printed  in  the  highest  style  of  the 
Dalton's  hook  for  tlie  classes  for  which  it  is  intend-  printer's  art,  and  the  illustrations  are  truly  Htlmira- 
eii,  satisfied  as  we  are  that  it  is  better  adapted  to  hie  tor  their  clearness  in  expressing  exactly  what 
their  use  than  any  other  work  of  the  kind  to  wliich  ,  their  author  intended. — Boston  Medical  and  Surgi- 
they  have  access. — American  Journal  of  the  Med.  :  cal  Journal,  March  28,  1S61. 

Sciences,  April,  18CL.  It..-  ^      •  j  ^     i    r^i       jj-^- 

'^      '  I      It  is  unnecessary  toeive  a  detail  of  theadditions; 

It  is,  therefore,  no  disparagement  to  the  many  ;  suffice  it  to  say,  that  they  are  numerous  and  import- 
books  upon  physiology,  most  excellent  in  their  day,  ,  ant,  and  such  as  will  render  the  work  still  more 
to  say  that  Dalton's  is  the  only  one  that  gives  us  the  I  valuable  and  acevptable  to  the  profession  as  a  learn- 
science  as  it  was  known  to  the  best  piiilosophers  ed  and  ci.'ginal  treatiseon  thisall-importanr,  branch 
throughout  the  world,  at  the  beginning  of  the  cur-  I  of  medicine.  All  that  was  said  in  commendation 
rent  year.  It  states  in  comprehensive  but  concise  !  of  the  gettingup  of  the  firstedition, and  the  superior 
diction,  the  facts  established  by  experiment,  or  [  style  of  the  illustrations,  apply  with  equal  force  to 
other  method  of  demonstration,  and  details,  in  an  this.  No  better  work  on  physiology  cm  he  placed 
understandable  manner,  how  it  is  done,  but  abstains  j  in  the  hand  of  the  student. — St.  Louis  Medical  and 
from  thediscussion  of  unsettled  or  theoreticalpjints.  ;  Surgical  Journal,  May,  1861. 

Herein  it  is  unique;  and  these  characteristics  ten  These  additions,  while  tes:ifying  to  the  learning 
^.er  It  a  text-book  without  a  rival,  for  those  who  j  ^nd  industry  of  the  author,  render  the  book  exceed- 
desire  to  study  physiological  science  as  it  is  known  ■  in„iy  useful,  as  the  most  complete  expose  of  a  s'.'i- 
t,o  Its  niost  successful  cultivators.  And  it  is  physi-  |  e„ce,  of  which  Dr.  Dalton  is  doubtless  the  ablest 
ology  thus  presented  that  lies  at  the  foundation  of  !  representative  on  this  side  of  the  Atlantic.— JVeu> 


correct  pathological  knowledge ;  and  this  in  turn  is 
the  basis  of  rational  therapeutics  ;  so  that  patholo- 
gy, in  fact,  becomes  of  prime  importance  in  the 
proper  discharge  of  our  every-day  practical  duties. 
. — Cincinnati  Lancet,  May,  1861. 

Dr.  Dalton  needs  no  word  of  praise  from  us.  He 
is  universally  recognizea  as  among  the  first,  if  not 
ttie  very  fiist,  of  American  physiologists  now  living. 
Tlie  first  edition  of  hisadmirable  work  appeared  but 
two  years  since,  and  the  advance  of  science,  his 


Orleans  Med.  Times,  May,  1861. 

A  second  edition  of  this  deservedly  popular  work 
having  been  called  for  in  the  short  space  of  two 
years,  the  author  has  supplied  deficiencies,  which 
existed  in  the  former  volume,  and  has  thus  more 
completely  fulfilled  his  design  of  presenting  to  the 
profession  a  reliable  and  precise  text- book,  and  one 
which  we  consider  the  best  outline  on  the  subject 
of  which  it  treats,  in  any  language. — N.  American 
Medico-C kirurg .  Review,  May,  1861. 


DUNGLISON,    FORBES,   TWEEDIE,    AND   CONOLLY. 
THE  CYCLOPAEDIA  OF  PRACTICAL  MEDICINE:  comprising  Treatises  on 

the  Nature  and  Treatment  of  Diseases,  JMateria  Medica,  and  Therapeutics,  Diseases  of  Women 
and  Children,  Medical  Jurisprudence,  &c.  &c.      In  four  large  super-royal  octavo  volumes,  of 
3254  double-columr.ed  pages,  strongly  and  handsomely  bound,  with  raised  bands.     SI-")  00. 
*^*  This  work  contains  no  less  than  four  hundred  and  eighteen  distinct  treatises,  contributed  by 

sixty-eight  distinguished  physicians,  rendering  it  a  complete  library  of  reference  for  the  country 

practitioner. 


The  most  complete  work  on  Practical  Medicine 
sxtant;  or,  at  least,  in  our  inngniige.— Buffalo 
Medical  and  Surgical  Journal. 

For  reference,  it  is  above  all  price  to  every  prac- 
titioner.—  Western  Lancet. 

One  of  the  most  valuable  medical  publications  of 
the  day — as  a  work  of  reference  it  is  invaluable. — 
Western  Journal  of  Medicine  and  Surgery. 

It  has  been  to  us,  both  as  learner  and  teacher,  a 
work  for  ready  and  frequent  reference,  one  in  which 
modern  English  medicine  is  exhibited  in  the  most 
advantageous  light. — Medical  Examiner. 


The  editors  are  practitioners  of  established  repu- 
tation, and  the  list  of  contributors  embraces  many 
of  the  most  eminent  professorsand  teachers  of  Lon- 
don, Edinburgh,  Dublin,  and  Glasgow.  It  is,  in- 
deed, the  great  meritol  tliis  work  that  theprincipal 
articles  have  been  furnished  by  practitioners  who 
have  not  only  devoteO  especial  attention  to  the  dis- 
eases about  which  they  have  written,  but  have 
also  enjoyed  opportunitiet  for  an  extensive  practi- 
cal acquaintance  with  them  and  whose  reputation 
carries  the  assurance  of  theircompetency  justly  to 
appreciate  the  opinions  ot  others,  while  it  stamps 

their  own  doctrines  witli  high  and  just  authority. 

American  Medical  Journal. 


DEWEES'S  COMPREHENSIVE   SYSTEM  OF  I 
MIDWIFERY.    Illustrated  by  occasional  eases 
and  many  engravings.     Twelfth  editicm,  with  the  ' 
author's  last  improvements  and   corrections      In  I 
oneoctavovoluine,  extra  cloth ,  of  (i(l()p.-\ges   SfJl  511. 

BEWEES'S  TREATISE  ON   THE  PHYSICAL! 


AND  MEDICAL  TREATMENT  OF   CHILD 
REN.     The  last  edition.    In  one  volume,  oetavo, 
extra  cloth ,  HAS  pages.     9'2  S(> 

DEWEES'S  TREATISE  ON  THE  DISEASES 
OF  FK.MALKS.  Ttulh  edition.  In  one  volume, 
octavo  ejctra  cloth,  532  pages,  with  plates.  $3  00. 


12 


HENRY   C.   LEA'S  MEDICAL 


DUNGLISON    (ROBLEY),    M.D., 

Professor  of  Institutes  of  Medicine  in  the  Jefferson  Medical  College,  Philadelphia 

ENLARGED  AND  REVISED  EDITION  OF  1865— : Just  Issued.) 

MEDICAL   LEXICON;  a  Dictionary  of  Medical  Science,  containing  a  concise 

Explanation  of  the  various  Subjects  and  Terms  of  Anatomy,  Physiology,  Pathology,  Hygiene, 
Therapeutics.  Pharmacology,  Pharmacy,  Surgery,  Obstetrics,  Medical  Jurisprudence,  and  Den- 
tistry. Notices  of  Climate  and  of  Mineral  Waters ;  Formulae  for  Officinal,  Empirical,  and  Dietetic 
Preparations;  with  the  Accentuation  and  Etymology  of  the  Terms,  <ind  the  French  and  other 
Synonymes;  so  as  to  constitute  a  French  as  well  as  English  Medical  Lexicon.  Thoroughly 
revised  and  very  greatly  modified  and  augmented.  In  one  very  large  and  handsome  royal 
octavo  volume,  of  1048  double-columned  pages,  in  small  type ;  strongly  done  up  in  extra  cloih, 
$t)  00 ;  leather,  raised  bands,  $6  75 

Preface  to  the  New  Edition 
"  The  author  has  again  been  required  to  subject  his  Medical  Lexicon  to  a  thorough  revision. 
The  progress  of  Medical  Science,  and  the  consequent  introduction  of  new  subjects  and  terms, 
demanded  this;  and  he  has  embraced  the  occayion  to  render  more  complete  the  etymology  and 
accentuation  of  the  terms.  On  no  previous  revision  has  so  much  time  and  labor  been  expended  by 
him.  Some  idea  may  be  formed  of  this,  from  the  tact,  that  although  the  page  has  been  augmented 
in  all  its  dimensions,  not  fewer  than  between  sixty  and  seventy  pages  have  been  added. 

"As  the  author  has  remarked  on  former  occasions,  it  has  ever  been  his  ardent  wish  to  make  the 
■work  a  satislaciorvand  desirable — if  not  indispensable — lexicon,  in  which  the  inquirer  may  search, 
without  disappointment,  for  every  term  that  has  been  legitimated  in  the  nomenclature  of  the  science; 
and  he  confidently  presents  this  edition  as  having  more  claims  on  the  attention  of  the  practitioner 
and  student  than  its  predecessors. 

'  Once  more  the  auihor  gladly  seizes  the  opportunity  afforded  him  to  express  his  grateful  acknow- 
ledgments for  the  vast  amount  of  favor  which  has  been  extended  to  the  Dictionary." 
January,  ls65. 
The  object  of  the  auihor  from  the  outset  has  not  been  to  make  the  work  a  mere  lexicon  or  dic- 
tionary of  terms,  but  to  afford,  under  each  a  condensed  view  of  its  various  medical  relations,  and 
thus  to  render  the  work  an  epitome  of  the  existing  condition  of  medical  science.  Starting  with 
this  view,  the  immense  demand  whicn  has  existed  for  the  work  has  enabled  him,  in  repeated  re- 
visions, to  augment  its  completeness  and  usefulness,  until  at  lenglh  it  has  attained  the  position  of 
a  recognized  and  standard  authority  wherever  the  language  is  spoken.  This  has  only  been  accom- 
plished by  the  earnest  determination  to  bring  each  successive  edition  thoroughly  on  a  level  with 
the  most  advanced  condition  of  contemporary  medical  science,  and  on  no  previous  occasion  has 
this  demanded  a  more  patient  and  laborious  effort  than  in  rendering  the  present  edition  fully  equal 
to  the  wants  of  the  student  of  the  present  day,  and  in  no  previous  editions  has  the  amount  of  new 
matter  introduced  been  so  large.  While,  therefore,  the  reader  who  merely  desires  a  vocabulary 
explaining  the  terms  in  common  use  can  satisfy  himself  with  the  smaller  works,  such  as  Hoblyn's, 
the  student  and  practitioner  who  wish  a  work  to  which  they  can  at  all  times  refer  with  unfailing 
confidence  for  all  which  it  is  the  province  of  such  a  book  to  supply,  must  still,  as  heretofore,  keep 
the  latest  edition  of  "  Dunglison's  Dictionary"  wiihin  reach. 

The  mechanical  execution  of  this  edition  will  be  found  greatly  superior  to  that  of  previous  im- 
pressions. By  enlarging  the  size  of  the  volume  to  a  royal  octavo,  and  by  the  employment  of  a  smal! 
but  clear  type  on  extra  fine  paper,  the  additions  have  been  incorporated  without  materially  increas- 
ing the  buik  of  the  volume,  and  the  matter  of  two  or  three  ordinary  octavos  has  been  compressed 
into  the  space  of  one  not  unhandy  for  consultation  and  reference. 
A  few  notices  of  the  previous  editions  are  subjoined. 
This  worif,  the  appearance  of  the  fifteenth  edition 
of  which  it  has  become  our  duty  and  pleasure  to 
announce, is  perhaps  the  most  stupendous  monument 
of  labor  and  erudition  in  niedica!  literature.     One 


would  hardly  suppose  after  constant  use  of  the  pre- 
ceding editions,  where  we  have  never  failed  to  find 
a  suflTieiently  full  explanation  of  everj  medical  term, 
that  in  this  edition  ^'^  about  six  thousand  subjects 
and  terms  have  been  adiJed,"  with  a  careful  revision 
and  correction  of  the  entire  work.  It  is  only  neces- 
sary to  announce  the  advent  of  this  edition  to  make 
it  occupy  the  place  of  the  preceding  one  on  the  table 
of  every  medical  man,  as  it  is  withoutdoubt  the  best 
and  most  comprehensive  work  of  the  kind  which  has 
ever  appeared. — Buffalo  Med.Journ.,  Jan.  1858. 

The  work  is  a  monument  of  patient  research, 
skilful  judgment,  and  vast  physical  labor,  that  ^vill 
perpetuate  the  name  of  the  author  more  effectually 
than  any  possible  device  of  stone  or  metal.  Dr. 
Dunplison  deserves  the  thanks  not  only  of  the  Ame- 
rican profession,  but  of  the  whole  medical  world. — 
North  Am.  Medico-C hir .  Review,  Jan.  1858. 

A  Medical  Dictionary  better  adapted  for  the  wants 
of  the  profession  than  any  other  with  which  we  are 
acquainted,  and  of  a  character  which  places  it  far 

above  comparison  and   competition Am.  Journ. 

Med.  Sciences,  Jan.  1858. 

We  need  only  say,  that  the  addition  of  6,000  new 
terms,  with  their  accompanying  definitions,  may  be 
■aid  to  constitute  a  new  work,  by  itself.  We  have 
examined  the  Dictionary  attentively,  and  are  most 
happy  to  pronfpunce  it  unrivalled  of  its  kind.  The 
erudition  displayed,  and  the  extraordinary  industry 
which  must  have  been  demanded,  in  its  preparation 
and  perfection,  redound  to  the  lasting  credit  of  its 


author,  and  have  furnished  us  with  a  volume  indis- 
pensable at  tIA  present  day,  to  all  who  would  find 
themselves  aWniveau  with  the  highest  standards  of 
medical  informatiop. — Boston  Medical  and  Surgical 
Journal,  Dec.  .31,  1857. 

Good  lexicons  and  encyclopedic  works  generally, 
are  the  most  labor-saving  contrivances  which  lite- 
rary men  enjoy  ;  and  the  labor  which  is  required  to 
produce  them  in  the  perfect  manner  of  this  example 
s  something  appalling  to  contemplate.  The  author 
tells  us  in  his  preface  that  lie  has  added  about  six 
thousand  terms  and  subjects  to  this  edition,  which, 
before,  was  considered  universally  as  the  best  work 
of  the  kind  in  any  language. — Silliman's  Journal, 
March,  1858. 

A  complete  and  thorough  exponent  of  medical 
terminology,  without  rival  or  possibility  of  rivalry. 
— Nashville  Journ.  of  Med.  and  Surg.,  Jan.  1858. 

It  is  universally  acknowledged,  we  believe,  that 
this  work  is  incomparably  the  best  and  most  com- 
plete Medical  Lexicon  in  the  English  language. 
Comment  and  commendation  are  unnecessary,  as  no 
one  at  the  present  day  thinks  of  purchasing  any  other 
Medical  Dictionary  than  this. — St.  Louis  Med.  and 
Surg.  Journ.,  Jan   1858. 

It  is  the  foundation  stone  of  a  good  medical  libra- 
ry, and  should  always  be  included  in  the  first  list  of 
books  purchased  by  tiie  medical  student. — Am.  Med. 
Monthly,  Jan.  1858.  \ 

It  is  scarcely  necessary  to  remark  that  any  medi- 
cal library  wanting  a  copy  of  Dunglison's  Lexicon 
must  be  imperfect. — Cin.  Lancet,  Jan.  1858. 

Thepresentcdition  we  may  safely  say  has  no  equal 
in  the  world. — Peninsular  Med.  Journal ^  Jan.  1856. 


AND    SCIENTIFIC    PUBLICATIONS. 


13 


1 

DUNGLISON    (ROBLEY),    M.D., 

Professor  of  Institutes  of  Medicine  in  the  JclTcrson  Medicul  College,  Philadelphia. 

HUMAN    PHYSIOLOGY.     Eighth  edition.      Thoroughly  revised  and  extcn- 

sively  modified  and  enlarged,  with  five  hundred  and  thirty-two  iilu.-^lrations.    In  two  large  and 
handsomely  printed  octavo  volumen,  extra  cloth,  of  about  1500  pages.     $7  00. 

In  revising  this  work  for  its  eighth  appearance,  the  author  has  spared  no  labor  to  render  it  worthy 
a  continuance  of  the  very  great  favor  which  has  been  extended  to  it  by  the  profession.  The  whole 
contents  have  been  rearranged,  and  to  a  great  extent  remodelled;  the  investigationd  which  of  late 
years  have  been  so  numerous  and  so  important,  have  been  carefully  examined  and  incorporated, 
and  the  work  in  every  respect  has  been  brought  up  to  a  level  with  the  present  state  of  the  subject. 
The  object  of  the  author  has  been  to  render  it  a  concise  but  comprehensive  treatise,  containing  the 
whole  body  of  physiological  science,  to  which  the  student  and  man  of  science  can  at  all  times  refer 
with  the  certainly  of  finding  whatever  they  are  in  search  of,  fully  presented  in  all  its  aspects;  and 
on  no  former  edition  has  the  author  Iwstowed  more  labor  to  secure  this  result. 


We  believe  that  itcan  truly  be  said,  no  more  com- 
plete repertory  of  facts  upon  the  subject  treated, 
can  anywhere  be  found.  Theauthor  lias,  moreover, 
that  enviable  tact  at  description  and  that  facility 
and  ease  of  expression  which  render  him  peculiarly 
acceptable  to  the  casual,  or  the  studious  reader. 
This  faculty,  so  requisite  in  setting  forth  many 
graver  and  less  attractive  subjects,  lends  additional 
charms  to  one  always  fascinating. — Boston  Med. 
mnd  Surg.  Journal. 

The  most  complete  and  satisfactory  system  of 
Physiology  in  the  English  language. — Amer.  Med 
Jexrnal . 


The  best  work  of  the  kind  in  the  Engliih  lan- 
guage.— Silliman's  Journal. 

The  present  edition  the  author  has  made  a  pcifcct 
mirror  of  the  science  as  it  is  at  the  present  hour. 
As  a  work  upon  physiology  proper,  the  science  of 
the  functions  performed  by  the  body,  the  student  wiH 
find  it  all  he  wishes. — Nashville  Journ.  of  Med. 

That  he  has  succeeded,  most  admirably  succeeded 
in  his  purpose,  is  apparent  from  the  appearance  of 
an  eighth  edition.  It  is  now  theereatencyclopaedia 
on  the  subject,  and  worthy  of  a  place  in  every  phy- 
sician's library. — Western  Lancet. 


BY   THE    SAME   AUTHOR. 


aENERAL   THERAPEUTICS    AND    MATERIA  MEDIOA;   adapted  for  a 

Medical  Text-book.  With  Indexes  of  Remedies  and  of  Diseases  and  their  Remedies.  Sixth 
Edition,  revised  and  improved.  With  one  hundred  and  ninety-three  illustrations.  In  two  large 
End  handsomely  printed  octavo  vols.,  extra  cloth,  of  about  1100  pages.    $6  50. 


In  announcing  a  new  edition  of  Dr.  Dunglison's 
General  Therapeutics  and  Materia  Medica,  we  have 
Eo  words  of  commendation  to  bestow  upon  a  work 
whose  merits  have  been  heretofore  so  often  and  so 
justly  extolled.  It  must  not  be  supposed,  however, 
that  the  present  is  a  mere  reprint  of  the  previous 
edition:  the  character  of  the  author  for  laborious 
research,  judicious  analysis,  and  clearness  of  ex- 
pression, is  fully  sustained  by  the  numerous  addi- 
tions he  lias  made  to  the  work,  and  the  careful  re- 
vision to  which  he  has  subjected  the  whole. — N.  A. 
Mtdico-Chir.  Review^  Jan.  1858. 


The  work  will,  we  have  little  doubt,  be  bought 
and  read  by  the  majority  of  medical  students:  its 
size,  arrangement,  and  reliability  recommend  it  to 
all ;  no  one,  we  venture  to  predict,  will  study  it 
without  profit,  and  there  are  few  to  whom  it  will 
not  be  in  some  measure  useful  as  a  work  of  refer- 
ence. The  young  practitioner,  more  especially ,  will 
find  the  copious  indexes  appended  to  this  ediiion  of 
great  assistance  in  the  selection  and  preparation  of 
suitable  formulae. — Charleston  Med.  Journ.  and  Re- 
view, Jan. 185S. 


BY   THE   SAME   AUTHOR. 


J?EW  REMEDIES,  WITH  FORMULA  FOR  THEIR  PREPARATION  AND 

ADMINISTRATION.    Seventh  edition,  with  extensive  Additions.    In  one  very  large  octavo 
volume,  extra  cloth,  of  770  pages.     $4  00. 


One  of  the  most  useful  of  the  author's  works. — 
Southern  Medical  and  Surgical  Journal. 

Tills  elaborate  and  useful  volume  should  be 
found  in  every  medical  library,  for  as  a  book  of  re- 
ference, for  physicians,  it  is  unsurpassed  by  any 
other  work  in  existence,  and  the  double  index  for 
diseases  and  for  remedies,  will  be  found  greatly  to 
anhance  its  value. — New  York  Med.  Gazette. 


The  great  learning  of  the  author,  and  his  remark- 
able industry  in  pushing  his  researches  into  every 
source  whence  information  is  derivable, have  enabled 
him  to  throw  together  an  extensive  mass  of  facts 
and  statements,  accompanied  by  full  reference  to 
authorities;  which  last  feature  renders  the  work 
practically  valuable  to  investigators  who  desire  to 
examine  the  original  papers. — The  American  Journal 
of  Pharmacy. 


ELLIS  (BENJAMIN),  M.D. 
THE   MEDICAL  FORMULARY :  being  a  Collection  of  Prescriptions,  derived 

from  the  writings  and  practice  of  many  of  the  most  eminent  physicians  of  America  and  Europe. 
Together  with  the  usual  Dietetic  Preparations  and  Antidotes  for  Poisons.  To  which  is  added 
an  Appendix,  on  the  Endermic  use  of  Medicines,  and  on  the  use  of  Ether  and  Chloroform.  The 
whole  accompanied  with  a  few  brief  Pharmaceutic  and  Medical  Observations.  Eleventh  edition, 
carefully  revised  and  much  extended  by  Robert  P.  Thomas,  M.  D.,  Professor  o(  Materia  Me- 
dica in  the  Philadelphia  College  of  Pharmacy.  In  one  volume,  Svo.,  of  about  350  pages.  $3  00. 
(Just  Issued.) 

On  no  previous  edition  of  this  work  has  there  been  so  complete  and  thorough  a  revision.  The 
extensive  changes  in  the  new  United  Stales  Pharinacopteia  have  necessitated  corresponding  alter- 
ations in  the  Formulary,  to  conform  to  that  national  standard,  while  the  progress  made  in  the 
materia  medica  and  the  arts  of  prescribing  and  dispensing  during  the  last  ten  years  have  been  care- 
fully noted  and  incorporated  throughout.  It  is  therefore  presented  as  not  only  worihv  a  continuance 
of  the  favor  so  long  enjoyed,  but  as  more  valuable  than  ever  to  the  practitioner  and  'pharmaceutist. 
Those  who  possess  previous  editions  will  find  the  additional  matter  of  sutTicieul  importance  to 
wari'aiit  their  adding  the  present  to  their  libraries. 


14 


HENRY  C.   LEA'S  MEDICAL 


ERICHSEN    (JOHN), 

Professor  of  Surgery  in  University  College,  London,  &,e. 

THE  SCIENCE  AND  ART  OF  SURGERY;  being  a  Treatise  on  Surgical 

Injuries,  Diseasks,  and  Operations.    New  and  improved  American,  from  the  second  enlarged 

and  carefully  revised  London  edition.    Illustrated  with  over  four  hundred  engravings  on  wood. 

In  one  large  and  handsome  octavo  volume,  of  one  thousand  closely  printed  pages,  extra  cloth, 

$6  00. 

The  very  distinguished  favor  with  which  this  work  has  been  received  on  both  sides  of  the  Atlan- 
tic has  stirnuiatec^  the  author  to  render  it  even  more  worthy  of  the  position  which  it  has  so  rapidly 
attained  as  a  standard  authority.  Every  portion  has  been  carefully  revised,  numerous  addition's 
have  been  made,  and  the  most  watchful  care  has  been  exercised  to  render  it  a  complete  exponent 
of  the  most  advanced  condition  of  surgical  science.  In  this  manner  the  work  has  been  enlarged  by 
about  a  hundred  pages,  while  the  series  of  engravings  has  been  increased  by  more  than  a  hundred, 
rendering  it  one  of  the  most  thoroughly  illustrated  volumes  before  the  profession.  The  additions  ol 
the  author  having  rendered  unnecessary  most  of  the  notes  of  tl>e  former  American  editor,  but  little 
has  been  added  in  this  country;  some  tew  notes  and  occasional  illustrations  have,  however,  been 
introduced  to  elucidate  American  modes  of  practice. 
It  is,  in  our  humble  judgment,  decidedly  the  best    excellent  contribution  to  surgery,  as  probably  the 


Dock  of  the  kind  in  the  Knglish  language.  Strange 
thai  just  such  books  are  noloftener  produced  by  pub- 
lic leaehers  of  surgery  in  this  country  and  Great 
Britain.  Indeed,  it  is  a  matter  of  great  astonishment 
but  no  less  true  than  astonishing,  that  of  the  many 
works  on  surgery  republished  in  this  country  within 
the  last  fifteen  or  twenty  years  as  text-books  for 
medical  students,  this  is  the  only  one  that  even  ap- 
proximates to  ihe  fulfilment  of  the  peculiar  wants  of 
young  men  just  entering  upon  the  sludy  of  this  branch 
of  the  profession. —  Western  Jour  .of  Med.  and  Surgery 

Its  value  is  greatly  enhanced  by  a  very  copious 
well-arranged  index.  AVe  regard  this  as  one  of  the 
most  valuable  contribulionsto  modern  surgery.  To 
one  entering  his  noviliate  of  practice,  we  regard  ii 
the  most  serviceable  guide  which  he  can  consult.  He 
will  find  a  fulness  of  detail  lead  Ine  him  throLgh  every 
step  of  the  operation,  and  not  deserting  him  until  Ihe 
final  issue  of  the  case  is  decided. — Sethoscope. 

Embracing,  as  will  be  perceived,  the  whole  surgi 
cal  domain,  and  each  division  of  it,self  almost  com 
plete  and  perfect,  each  chapter  full  and  explicit,  eaci 
subject  faithfully  exhibited,  we  can  only  express  ou 
estimate  of  it  in  the  aggregate.    We  consider  it  ai 


best  single  volume  now  extant  on  the  subject,  and 
with  great  pleasure  we  add  it  to  our  text-books. — 
Waskville  Journal  of  Medicine  and  Surgery . 

Prof  Ericbsen's  work,  for  its  size,  has  not  been 
surpassed;  his  nine  hundred  and  eight  pages,  pro- 
fusely illustrated,  are  rich  in  physiological,  patholo- 
gical, and  operative  suggestions,  doctrines,  detail*, 
and  processes  ;  and  will  prove  a  reliable  resource 
for  information,  both  to  physician  and  surgeon,  in  th« 
hour  of  peril. —  N.  0.  Med.  and  Surg.  Journal. 

We  may  say,  after  a  careful  perusal  of  some  of 
the  chapters,  and  a  more  hasty  examination  of  th'i 
remainder,  that  it  must  raise  the  character  of  the 
author,  and  reflect  great  credit  upon  the  ccillege  lo 
which  he  is  professor,  and  we  can  cordially  recom- 
mend it  as  a  wiirk  of  reference  botti  to  students 
and  practitioners. — Med.  Times  and  Gazette. 

We  do  not  hesitate  to  say  that  the  volume  before 
us  gives  a  veiy  admirable  practical  view  of  the  sci- 
ence and  art  of  Surgery  of  the  present  day,  and  we 
have  no  doubt  that  it  will  be  highly  valued  as  a 
surgical  guide  as  well  by  the  surge<m  as  by  the 
student  of  surgery.  —  Edinburgh  Med.  and  Swg. 
Journal. 


FISKE  FUND  PRIZE  ESSAYS  —  THE  EF- 
FECTS OF  CLIMATE  ON  TUBERCULOUS 
DISEASE.  By  Edwin  Lee,  M.R.C.S  ,  London, 
and  THE  INFLUENCE  (»F  PREGNANCY  ON 
THE  DEVELOPMENT  OF  TUBERCLES     By 


Edward  AVarbkn,  M.D.,of  Edenton,N.  C.  To- 
gether in  one  neat  8vo.  volume,  extra  cloth.  SI  00. 
FRICK  ON  RENAL  AFFECTIONS;  their  Diag- 
nosis  and  Pathology.  With  illustrations.  On* 
volume,  royal  12mo.,  extra  cloth.    75  cents. 


FERGUSSON  (WILLIAM),  F.  R.  S., 

Professor  of  Surgery  in  King's  College,  London,  &c. 

A  SYSTEffI  OF  PRACTICAL  SURGERY.     Fourth  American,  from  the  third 

and  enlarged  London  edition.    In  one  large  and  beautifully  printed  octavo  volume,  of  about  70© 
pages,  with  393  handsome  illustrations,  leather.     $4  OO. 


FOWNES  (GEORGE),  PH.  D.,  &c. 
A  MANUAL  OF  ELEMENTARY  CHEMISTRY;  Theoretical  and  Practical. 

With  one  hundred  and  ninety-seven  illustrations.     Edited  by  Robert  Bridges,  M.  D.    In  one 

large  royal  12mo.  volume,  of  600  pages,  extra  cloth,  $2  00. 

The  death  of  the  author  having  placed  the  editorial  care  of  this  work  in  the  practised  hands  ol 
Drs.  Bence  Jones  and  A.  W.  Hoffman,  everything  has  been  done  in  its  revision  which  experience 
could  suggest  to  keep  it  on  a  level  with  the  rapid  advance  of  chemical  science.  The  additions 
requisite  to  this  purpose  have  Heces>itated  an  enlargement  of  Ihe  page,  notwithstanding  which  the 
work  has  been  increased  by  about  fifty  pages.  At  the  same  time  every  care  has  been  used  to 
maintain  its  distinctive  character  as  a  condensed  manual  for  the  student,  divested  of  all  unnecessary 
detail  or  mere  theoretical  speculation.  The  additions  have,  of  course,  been  mainly  in  the  depart- 
ment of  Organic  Chemistry,  which  has  made  such  rapid  progiess  within  the  last  few  years,  but 
yet  equal  attention  has  been  bestowed  on  the  other  branches  of  the  subject — Chemical  Physics  and 
Inorganic  Chemistry — to  present  all  investigations  and  discoveries  of  imporlance,  and  to  keep  up 
the  reputation  of  the  volume  as  a  complete  manual  of  the  whole  science,  admirably  adapted  for  the 
learner.  By  the  use  of  a  small  but  exceedingly  clear  type  the  matter  of  a  large  i>ciavo  is  compressed 
wiihin  the  convenient  and  portable  limits  of  a  moderate  sized  duodecimo,  and  at  the  very  low  price 
affixed,  It  is  offered  as  one  of  the  cheapest  volumes  before  the  profession. 


Dr.  Fownes' excellent  work  lias  liecn  iiniversiilly 
recognized  everywhere  in  his  f)wn  and  this  country, 
as  the  best  elementary  treatise  on  chemistry  in  the 
Enrlish  tongue,  and  is  very  generiillv  adopted,  we 
believe,  as  the  standard  text- book  in  all  <  ureiil  leges, 
both  literary  and  scientific. — OkarUston  Med  Journ. 
and  Revieu) 


The  work  of  Dr.  Fownes  has  long  been  before 
the  public,  and  its  merits  have  been  fully  appreci- 
ated as  the  best  text-book  on  chemistry  now  in 
existence.  We  do  not,  of  course,  place  it  in  a  rank 
superior  to  the  works  of  Brande,  Graham,  Turner, 
firegory,  or  Gniclin,  but  we  say  that,  as  a  wori 
for  sludents,  it  is  preferable  to  any  of  them. —  Lo» 
don  Journal  of  Medicine. 


AND    SCIENTIFIC    PUBLICATIONS. 


l.") 


FLINT  (AUSTIN),  M .  D., 

ProfesBorof  the  Principles  and  Practice  of  Medicine  in  Ildlevue  Hosp.  Med.  College,  New  York. 

Now  Eea'ty,  1^5013. 

THE   PRTNCIPLES    AND   PR.VCTICK  OK    MKDICINE.      For  the  use  of 

Practiliotiers  and  Smdents.      In  one  largfe  and   hand-<om<»  octavo  volume  of  over  850  closely 

printed  pages,  leather,  raifctl  bunds,  $7;  handsonie  extra  cloth,  $tj. 

The  want  has  for  some  time  been  (elt  in  this  cotnitry  of  a  volume  which,  within  a  moderate 
compass,  should  give  a  clear  and  connected  view  of  general  and  special  patliology  and  therapeutics 
ifi  their  most  modern  aspect.  Re  rent  researches  have  modified  many  opinions  which  vere  formerly 
universally  received  on  important  points  both  of  theory  and  practice,  and  the«e  changes  nave  per- 
haps as  yet  scari^ely  received  the  attention  due  to  them  in  the  works  accessible  to  the  profession. 
The  author's  reputation  as  a  ifuclier  is  a  guarantee  that  the  present  volume  will  be  fully  up  to  the 
most  advanced  state  of  the  science  of  the  day,  while  his  long  and  varied  exoerienf-e  as  a  oracti- 
tioner  will  insure  that  m  all  practical  details  his  work  will  be  a  sound  and  Irustworlhy  guide. 

BY  THE  SAME  AUTHOR.     {Preparing.) 

PHYSICAL  EXPLORATION  AND  DIAGNOSIS  OF  DISEASES  AFFECT- 

iNG  THE  RESPIRATORY  ORGANS.    Second  edition.    In  one  large  and  handsome  octavo 
volume,  eitia  cloth. 

BY  THE  SAME  AUTHOR. 

A  PRACTICAL  TREATISE  ON  THE  DIAGNOSIS,  PATHOLOGY,  AND 

TREATMENT  OF  DISEASES  OF  THE  HEART.     In  one  neat  octavo  volume,  of  about 
500  pages,  extra  cloth.     $3  50. 


We  do  not  know  that  Dr.  Flint  has  written  any- 
thing which  is  not  first  rate  ;  but  this,  his  latest  con- 
irihution  to  medical  literature,  in  our  opinion,  sur- 
passes all  the  others.  The  work  is  most  comprehen- 
liive  in  its  scope,  and  most  sound  in  the  views  it  enun- 
ciates. The  descriptions  are  clear  and  methodieal ; 
the  fctatemeuts  are  substantiated  by  facts,  and  are 


made  with  such  simplicity  and  sincerity,  that  with- 
out them  they  would  carry  conviction.  The  style 
is  admirably  clear,  direct,  and  free  from  dryness. 
With  Dr.  Walshe's  excellent  treatise  before  us,  we 
have  no  hesitation  in  sayinsr  that  Dr.  Flint's  book  is 
the  best  work  on  the  heart  in  the  English  language. 
—Boston  Med.  and  Sitrg.  Journal. 


GRAHAM  (THOMAS),  F.  R.  S. 
THE  ELEMENTS   OF  INORGANIC   CHEMISTRY,  including  the  Applica- 

tions  of  the  Science  in  the  Arts.  New  and  much  enlarged  edition,  by  Henry  Watts  and  Robert 
Bridges,  M.  D.  Complete  in  one  large  and  handsome  octavo  volume,  ol  over  800  very  large 
pages,  with  two  hundred  and  thirty-two  wood-cuts,  extra  cloth.     $5  50. 

**^  Part  II.,  completing  the  work  from  p.  431  to  end,  with  Index,  Title  Mattel*,  &c.,  may  be 
feaa  separate,  cloth  backs  and  paper  sides.     Price  $3  00. 

From  Prof.  E.  N.  Horsford,  Harvard  College.  |  afford  to  be  without  this  edition  of  Prof.  Graham's 
It  has,  in  its  earlier  and  less  perfect  editions,  been  ^  Elements.— SiZitjnan'j  JowrnaZ,  March,  1858. 


familiar  to  me,  and  the  excellence  of  its  plan  and 
the  clearness  and  completeness  of  its  discussions, 
bave  long  been  my  admiration. 
No  reader  of  English  works  on  this  science  can 


From  Prof.  Wolcott  Gibbs,  N.  Y.  Free  Academy 
The  work  is  an  admirable  one  in  all  respects,  and 
its  republication  here  cannot  fail  to  exert  a  positive 
influence  upon  the  progress  of  science  in  this  country. 


GRIFFITH  (ROBERT  EJ,  M.  D.,  &c. 

A  UNIVERSAL  FORMULARY,  containing  the  methods  of  Preparing  and  Ad- 
ministering Officinal  and  other  Medicines.  The  whole  adapted  to  Physicians  and  Pharmaceu- 
tists. Second  Edition,  thoroughly  revised,  with  numerous  additions,  by  Robert  P.  Thomas,' 
M,  D.,  Professor  of  Materia  Medica  in  the  Philadelphia  College  of  Pharmacy.  In  one  large  and 
handsome  octavo  volume,  extra  cloth,  of  650  pages,  double  columns.     $4  00. 

It  was  a  work  requiring  much  perseverance,  and  i  vision  and  ample  additions  of  Dr  Thomas,  and  is 
wrhen  published  was  looked  upon  as  by  far  the  besij  now,  we  believe,  one  of  the  mosi  coihplete  \vorks 
work  of  its  kind  that  had  issued  from  the  American  >  of  its  kind  in  any  language.  The  additions  amount 
press.  Prof  Thomas  has  certainly  "improved,"  as  ;  to aboulseveniy  pages, and  no  effort  has  been  spared 
•well  as  added  to  this  Formulary,  and  has  rendered  it  j  to  include  in  them  all  the  recent  improvements.  A 
*dditionally  deserving  of  the  confidence  of  pharma- 1  work  of  this  kind  appears  to  us  indispensable  to  the 
ceutists  and  physicians. — Am.  .Journal  of  Pharmacy .    i  physician,  and  there  is  none  we  can  more  cordiallv 

We  are  happy  to  announce  a  new  and  improved   '"ecoramend—JV.  Y.  Journal  of  Medidn*. 
edition  of  this,  one  of  ihe  most  valuable  and  useful  .  .^,     l^j         ..       e  ^ 

works  that  have  emanated  from  an  American  pen.!  Pre-eminent  among  the  hestand  most  useful  corn- 
it  would  do  credit  to  any  country,  and  will  be  found  '  Pil»tions  of  he  present  day  will  be  found  the  work 
of  daily  usefulness  to  practitioners  of  medicine;  it  is  1  before  us,  which  can  have  been  produced  only  at  a 
better  adapted  to  their  purposes  than  the  dispensato-  very  great  cost  of  thought  and  labor.  A  short  de- 
ries.— SoutA«rn  Med.  avid-  Surg.  Journal.  '  scription  will  suffice  to  show  that  we  do  not  put  too 

Itisoneofthe  most  useful  books  a  country  practl 
iio  ifrcan  nos.«iblv  have. — Medical  Chronicle. 

This  if  a  work  of  six  hundred  and  fiflyone  pages 
embracing  all  on  the  subject  of  preparing  and  admi 
liislering  medicines  thai  can  'le  desired  by  the  physi 
cian  and  pharmaceutist. —  Westerti  Lancet. 

The  amountof  useful,  every-day  matter. for  aprac 
ticing  physician,  is  really  immense. — Boston  Med 
and  Surg.  Journal. 

This  edition  has  been  greailj  improved  by  the  re- 


put  too 

high  an  estimate  on  this  work  We  are  not  cogni- 
zant of  the  existence  of  a  parallel  work.  Its  value 
will  be  apparent  to  our  readers  from  tne  sketch  of 
its  contents  above  given.  We  strongly  recommend 
it  to  all  who  are  engaged  either  in  practical  medi- 
cine, or  more  exclusively  with  its  literature. — Lotid. 
Med.  Gazette. 

A.  very  useful  work,  and  a  most  complete  compen- 
dium on  the  subjiet  of  materia  raediea.  We  know 
of  no  wDik  in  our  languaaie,  or  any  other,  so  com- 
prehensive in  all  its  details. — London  Lancet. 


16 


HENRY   C.    LEA'S  MEDICAL 


GROSS  (SAMUEL  D.),   M.  D., 

Professor  of  Surgery  in  the  Jefferson  Medical  College  of  Philadelphia,  Sec. 
Enlarged  Edition. 

A  SYSTEM  OP  SURGERY :  Pathological,  Diagnostic,  Therapeutic,  and  Opera- 
tive. Illustrated  by  over  Thirteen  Hundred  Engravings.  Third  edition,  much  enlarged  and 
carefully  revised.  In  two  large  and  beaulifully  printed  royal  octavo  volumes,  of  2200  pages ; 
leather.     $15  03.     (Just  Issued.) 

The  exhaustion  within  five  years  of  two  large  editions  of  so  elaborate  and  comprehensive 
a  work  as  this  is  the  best  evidence  that  the  author  was  not  mistaken  in  his  estimate  of  the 
want  which  existed  of  a  complete  American  System  of  Surgery,  presenting  the  science  in  all  ita 
necessary  details  and  in  all  its  branches.  That  he  has  succeeded'in  the  attempt  to  supply  this  want 
is  shown  not  only  by  the  rapid  sale  of  the  work,  but  also  by  the  very  favorable  manner  in  which  it 
has  been  received  by  the  organs  of  the  profes>ion  in  this  country  and  in  Europe,  and  by  the  fact  that 
a  translation  is  now  preparing  in  Holland— a  mark  of  appreciation  not  often  bestowed  on  any  scien- 
tific work  so  extended  in  size. 

The  author  has  not  been  insensible  to  the  kindness  thus  bestcTwed  upon  his  labors,  and  in  revising 
the  work  for  a  third  edition  he  has  spared  no  pains  to  render  it  worthy  of  the  favor  with  which  it 
has  been  received.  Every  portion  has  been  subjected  to  close  examination  and  revision ;  any  defi- 
ciencies apparent  have  been  supplied,  and  the  results  of  recent  progress  in  the  science  and  art  ol 
surgery  have  been  everywhere  introduced;  while  the  series  of  illustrations  has  been  still  further 
enlarged,  rendering  it  one  of  the  most  thoroughly  illustrated  works  ever  laid  before  the  profession. 
To  accommodate  these  very  extensive  additions,  the  form  of  the  work  has  been  altered  to  a  royal 
octavo,  so  that  notwithstanding  the  increa.se  in  the  matter  and  value  of  the  book,  its  size  wil  be  found 
more  convenient  than  belore.  Every  care  has  been  taken  in  the  printing  to  render  the  typographical 
execution  unexceptionable,  and  it  is  confidently  expected  to  prove  a  work  in  every  way  worthy  ol 
a  place  in  even  the  most  limited  library  of  the  practitioner  or  student. 

Has  Dr.  Gross  satisfactorily  fulfilled  this  object?  I  confess  we  were  by  no  means  prepared  for  the  work 
A  careful  perusal  of  his  volumes  enables  us  to  g;ive  !  which  isbeforeus — the  most  complete  treatise  upon 
an  answer  in  the  affirmative.    Notonly  hashe  given    surgery  ever  published,  either  in  this  or  any  other 


to  the  reader  an  elaborate  and  well-written  account 
of  his  own  vast  experience,  but  he  has  not  failed  to 
embody  in  his  pages  the  opinions  and  practice  of 
surgeons  in  this  and  other  countries  of  Europe.  The 
result  has  been  a  work  of  such  completeness,  that  it 
has  no  superior  in  the  systematic  treatises  on  sur- 
gery which  have  emanated  from  English  or  Conti- 
nental authors.  It  has  been  justly  objected  that 
these  have  been  far  from  complete  in  many  essential 
particulars,  many  of  them  having  been  deficient  in 
gome  of  the  most  important  points  which  should 
characterize  such  works  Some  of  them  have  been 
elaborate — too  elaborate— with  respect  to  certain 
diseases,  while  they  have  merely  glanced  at,  or 
given  an  unsatisfactory  account  of,  others  equally 
important  to  the  surgeon.  Dr.  Gross  has  avoided 
this  error,  and  has  produced  the  most  complete  work 
that  has  yet  issued  from  the  press  on  the  science  and 
practice  of  surgery.  It  is  not,  strictly  speaking,  a 
Dicti(  nary  of  Surgery,  but  it  gives  to  the  reader  all 
the  infi^rination  that  he  may  require  for  his  treatment 
of  surgical  diseases.  Having  said  so  much,  it  might 
appear  superfluous  to  add  another  W')rd  ;  but  it  is 
only  due  to  Dr.  Gross  to  state  that  he  has  embraced 
the  opportunity  of  transferring  to  his  pages  a  vast 
number  of  engravings  from  English  and  other  au- 
thors, illustrative  ot  the  pathology  and  treatment  of 
surgical  diseases.  To  these  are  added  several  hun- 
dred original  wood-cuts.  The  work  altogether  com- 
mends itself  to  the  attention  of  British  surge(m8, 
from  whom  it  cannot  fail  to  meet  with  extensive 
patronage. — London  Lancet,  Sept.  1,  1860. 

Of  Dr.  Gross's  treatise  on  Surgery  we  can  say 
no  more  than  that  it  is  the  most  elaborate  and  com- 
plete work  on  this  branch  of  the  healing  art  which 
has  ever  been  published  in  any  country.  A  sys- 
tematic work,  it  admits  of  no  analytical  revicAVj 
but,  did  our  spack  permit,  we  should  gladly  give 
some  extracts  from  it,  to  enable  our  readers  to  judge 
of  the  classical  style  of  the  author,  and  the  exhaust- 
ing way  in  which  each  subject  is  treated. — Dublin 
Quarterly  Journal  of  Med.  Seienee. 

The  work  is  so  superior  to  its  predecessors  in 
matter  and  extent,  as  well  as  in  illustrations  and 
style  of  publication,  that  we  can  honestly  recom- 
mend it  as  the  best  work  of  the  kind  to  be  taken 
home  by  the  young  practitioner. — Am.  Med.  Journ. 

With  pleasure  we  record  the  completion  of  this 
long-nnticipsted  work.  The  reputation  which  the 
author  has  for  many  years  sustained,  both  as  a  sur- 
geon and  as  a  writer,  had  prepared  us  to  expect  a 
treatise  of  great  excellence  and  originality;  but  we 


country,  and  we  might,  perhaps,  safely  say,  the 
most  original.  There  is  no  subject  belonging  pro- 
perly to  surgery  which  has  not  received  from  the 
author  a  due  share  of  attention.  Dr.  Grots  has  sup- 
plied a  want  in  surgical  literature  which  has  long 
been  felt  by  practitioners ;  he  has  furnished  us  with 
a  complete  practical  treatise  upon  surgery  in  all  its 
departments  As  Arnencms,  we  are  proud  of  the 
achievement;  as  surgeons,  we  are  most  sincerely 
thankful  to  him  for  his  extraordnary  labors  in  our 
beiialf.— JV.  y.  Review  and  Buffalo  Med.  Journal. 
The  great  merit  of  the  work  may  be  stated  as 
follows.  It  presents  surgical  science  as  it  exists 
at  the  latest  date,  with  all  its  improvements  ;  and 
it  discusses  every  topic  in  due  proportion.  No- 
thing IS  omitted,  nothing  is  in  excess. — Chicago 
Med.  Examiner,  May,  1860. 

We  cannot  close  this  brief  notice  of  Dr.  Gross's 
most  valuable  and  excellent  compendium  of  Sur- 
geiy  without  again  drawing  attention  to  it,  as  we 
aid  in  our  notice  of  his  first  edition,  as  an  evidence 
of  the  progress  our  American  brethren  are  making 
towards  establishing  a  literature  of  their  own. — 
Dublin  Quarterly  Journal,  Feb.  186-3. 

It  has  been  characterized  by  the  representative 
press  and  by  individual  surgeons  of  the  highest 
eminence,  both  at  home  and  abroad,  as  "the  best 
systemntic  work  on  surgery  ever  published  in  the 
English  language ;"  and  that  the  profession  at 
large  have  given  substantial  proofs  of  their  agree- 
ment to  this  verdict,  is  sufficiently  evident  from  the 
fact  that  translations  into  European  languages  have 
been  called  for,  and  that  go  shortly  after  its  first 
appearance,  and  at  a  time  most  unfavorable  to 
literary  "enterprise,"  the  Philadelphia  publishers 
have  found  it  pay  to  issue  a  "  second  edition,  much 
enlarged  and  carefully  revised." — American  Med. 
Monthly,  May,  1862 

We  are  much  gratified  to  be  able  to  announce  a 
new  edition  of  this  Cyclopsedia  of  Surgtry.  Con- 
sidering the  large  size  of  the  work  and  its  expen- 
BJveness,  the  extremely  rapid  sale  and  exhaustion 
of  an  entire  edition,  not  only  proves  the  value  of 
the  work,  and  its  adaptation  to  the  wants  of  the 
profession,  but  it  speaks  well  for  the  inielligence 
of  AiHTican  surgeons. — American  Medical  Times, 
May,  186-2. 

A  valuable  and  even  necessary  addition  to  every 
surgical  library. — Chicago  Med.  Journ.,  Dec.  1859. 

A  system  of  surgery  which  we  think  unrivalled 
in  our  language. — British  American  Journal. 


BY  THE  SAME  AUTHOR. 

A  PRACTICAL  TREATISE  ON  FOREIGN  BODIES  IN  THE  AIR-PAS- 

SAGES.    In  one  handsome  octavo  volume,  extra  cloth,  with  illustrations,    pp.  468.    $2  75. 


AND    SCIENTIFIC   PUBLICATIONS. 


17 


GROSS  (SAMUEL  D.),  M.  D. 
Professor  of  Surgery  in  the  Jefferson  Medicul  College  of  Philadelpliia,  &.C. 

ELEMENTS  OF  PATHOLOGICAL  ANATOMY.     Third  edition,  thoroughly 

revified  and  greatly  improved.     In  one  large  and  very  handsome  octavo  volume,  with  about  three 

hundred  and  fifty  heuutiful  illustrations,  of  which  a  large  number  are  from  original  drawings, 

extra  cloth.     $4  UO. 

The  very  rapid  advances  in  the  Science  of  Pathological  Anatomy  during  the  last  few  years  have 
rendered  essential  a  thorough  modification  of  this  work,  with  a  view  of  making  it  a  correr-t  expo- 
nent of  the  present  state  of  the  subject.  The  very  careful  manner  in  which  this  task  has  been 
executed,  and  the  amount  of  alteration  which  it  has  undergone,  have  enabled  the  author  to  say  thai 
"  with  the  many  changes  and  improvements  now  introduced,  the  work  may  be  regarded  almost  as 
a  new  treatise,"  while  the  efforts  of  the  author  have  been  seconded  as  regards  the  mechanical 
execution  of  the  volume,  rendering  it  one  of  the  handsomest  productions  of  the  American  press. 


BY  THE  SAME  AUTHOR. 

A   PRACTICAL    TREATISE   ON   THE    DISEASES,    INJURIES,  AND 

MALFORMATIONS  OF  THE  URINARY  BLADDER,  THE  PROSTATE  GLAND,  AND 
THE  URETHRA.  Second  Edition,  revised  and  much  enlarged,  with  one  hundred  and  eighty- 
four  illustrations.  In  one  large  and  very  handsome  octavo  volume,  of  over  nine  hundred  pages, 
extra  cloth,  $4  00. 

Philosophical  in  its  design,  methodical  in  its  ar-  i  agree  with  us,  that  there  is  no  work  in  the  English 
rangement,  ample  and  sound  in  its  practical  details,    ■ 
it  may  in  truth  be  said  to  leave  scarcely  anything  to 
be  desired  on  so  important  a  subject. — Boston  Med. 
and  Surg  Journal. 

Whoever  will  peruse  the  vast  amount  of  valuable 
practical  information  it  contains,  will,  we  think, 


language  which  can  make  any^ust  pretensions  to 
be  its  equal. — iV.  Y.  Journal  ofMedirAne . 

A  volume  replete  with  truths  and  principles  of  th« 
utmost  val ue  in  th e  i nvestigation  of  these  diseases. — 
Atnerican  MedicalJournal . 


GRAY  (HENRY),   F.  R.  S., 

Lecturer  on  Anatomy  at  St.  George's  Hospital,  London,  &C. 

ANATOMY,  DESCRIPTIVE  AND   SURGICAL.      The  Drawings  by  H.  V. 

Carter,  M.  D.,  late  Demonstrator  on  Anatomy  at  St.  George's  Hospital;  the  Dissections  jointly 
by  the  Author  and  Dr.  Carter.    Second  American,  from  the  second  revised  and  improved 
London  edition.     In  one  magnificent  imperial  octavo  volume,  of  over  800  pages,  with  388  large 
and  elaborate  engravings  on  wood.     Price  in  extra  cloth,  $6  00;  leather,  raised  bands,  $7  00. 
The  speedy  exhaustion  of  a  large  edition  of  this  work  is  suflicient  evidence  that  its  plan  and  exe- 
cution have  been  found  to  present  superior  practical  advantages  in  facilitating  the  study  of  Anaio- 
mv      In  presenting  it  to  the  profession  a  second  time,  the  author  has  availed  himself  of  the  oppor- 
tunity to  supply  any  deficiencies  which  experience  in  its  use  had  shown  to  exist,  and  to  correct 
any  errors  of  detail,  to  which  the  first  edition  of  a  scientific  work  on  so  extensive  and  complicated 
a  science  is  liable.     These  improvements  have  resulted  in  some  increase  in  the  size  of  the  volume, 
while  twenty-six  new  wood-cuts  have  been  added  to  the  beautiful  series  of  illustrations  which 
form  so  distuictive  a  feature  of  the  work.     The  American  edition  has  been  passed  through  the  press 
under  the  supervision  of  a  competent  professional  man,  who  has  taken  evtii-y  care  to  render  it  in 
all  respects  accurate,  and  it  is  now  presented,  without  any  increase  of  price,  as  fitted  to  maintain 
and. extend  the  popularity  which  it  has  everywhere  acquired. 


With' little  trouble,  the  busy  practitioner  whose 
knowledge  of  anatomy  may  have  become  obscured  by 
want  of  practice,  may  now  resuscitate  his  former 
anatomical  lore,  and  be  ready  for  any  emergency. 
It  is  to  this  class  of  individuals,  and  not  to  the  stu- 
dent alone,  that  this  work  will  ultimately  tend  to 
be  of  most  incalculable  advantage,  and  we  feel  sat- 
isfied that  the  library  of  the  medical  man  will  soon 
be  considered  incomplete  in  which  a  copy  of  this 
work  does  not  exist.-  Madras  Quarterly  Journal 
of  Med.  Science,  July,  1861. 

This  edition  is  much  improved  and  enlarged,  and 
contains  several  new  illustrations  by  Dr.  Westma- 
eott.  The  volume  is  a  complete  companion  to  the 
dissecting-room,  and  saves  the  necessity  of  the  stu 
dent  possessing  a  variety  of  "  Manuals." — The  Lon- 
don Lancet,  Feb.  9,  1861. 

The  work  before  us  is  one  entitled  to  the  highest 
praise,  and  we  accordingly  welcome  it  as  a  valu- 
able addition  to  medical  literature.  Intermediate 
in  fulness  of  detail  between  the  treatises  of  S.iar- 
pey  and  of  Wilson,  its  characteristic  merit  lies  in 
the  number  and  excellence  of  the  engravings  it 
contains.  Most  of  these  are  original,  of  much 
larger  than  ordinary  size,  and  admirably  executed 


work  of  Mr.  Gray  to  the  attention  of  the  medical 
profession,  feeling  certain  thaf  it  should  be  regarded 
as  one  of  the  most  valuable  contributions  ever  made 
to  educational  literature. — N.  Y.  Monthly  Review. 
Dec.  1859. 

In  this  view,  we  regard  the  work  of  Mr.  Gray  aa 

far  better  adapted  to  the  wants  of  the  profession, 
and  especially  of  the  student,  than  any  treatise  on 
inatomy  yet  published  in  this  country.  It  is  destined, 
we  believe,  to  supersede  all  others,  both  as  a  manual 
L)f  dissections,  and  a  standard  of  reference  to  the 
atudent  of  general  or  relative  anatomy.  —  N.  Y. 
Journal  of  Medicine,  Nov.  1859. 

In  our  judgment,  the  mode  of  illustration  adopted 
in  the  present  volume  cannot  but  present  many  ad- 
vantages to  the  studentof  anatomy.  To  the  zealous 
disciple  of  Vesalius,  earnestly  desirous  of  real  im- 
provement, the  book  will  certainly  be  of  immense 
value;  but,  at  the  same  time,  we  must  also  confess 
that  to  those  simply  desirous  of  "cramming"  it 
will  be  an  undoubted  godsend.  The  peculiar  value 
of  Mr.  Gray's  mode  of  illustration  is  nowhere  m.ore 
markedly  evident  than  in  the  chapter  on  osteology, 
and  especially  in  those  portions  which  treat  of  the 


The  various  parts  are  also  lettered  after  the  plan  bones  of  the  head  and  of  their  development.  The 
adopted  in  Holden's  Osteology.  It  would  be  UifR-  j  study  of  these  parts  is  thus  made  one  of  comparative 
cult  to  over-estimate  the  advantages  offered  by  this  i  ease,  if  not  of  positive  pleasure:  and  those  buarhears 
mode  of  pictorial  illusiration.  liones,  ligaments,  \  of  the  student,  the  temporal  ana  sphenoid  bones,  are 
muscles,  bloodvessels,  and  nerves  are  each  in  turn  shorn  of  half  their  terrors.  It  is,  in  our  estimation, 
fiffured,  and  marked  with  their  appropriate  names;  |  an  admirable  and  complete  text-book  for  the  student, 
thus  enabling  the  student  to  comprehend,  at  a  glance,  ,  and  a  useful  work  of  reference  for  the  practitioner; 
wh'it  would  otherwise  often  be  ignored,  or  at  any  its  pictorial  character  forming  a  novel  element,  to 
rate,  acquired  only  by  prolonged  and  irksome  ap-  which  we  have  already  sufficiently  alluded. — Am, 
plication.    In  conclusion,  we  heartily  commend  the    Journ.  Med.  Set.,  July,  1859, 


18 


HENRV   C.   LEA'S   MEDICAL 


GIJ5Sl).\'i<  I.NSTrrUTKS  AND  PRACTICK  OF 
J*L.'RtiERV.     Kielilli  edilimi,  iinproved   aiid    ill 
tertd.    With  thirty-four  plates.    In  two  haiulsome 
octjivo  volumiB,  containing  about   1,000  pages, 
leather,  raised  bandi.     SO  50 

GARDiNER'S  AIEDlCAl-  CHEMISTRY,  for  the 
use  of  Students  and  the  Profession.  In  one  royal 
l'2mo.  vol.,  cloth,  pp.  306,  with  wood- cuts.     $1. 

GLUGE'S  ATLAS  OF  PATHOLOGICAL  HIS- 
TOLOGY Translated,  with  Notes  and  Addi- 
tions Ijy  Jo.sEPH  Leidy,  M.  D.  In  one  volume, 
very  lar^e  imperial  quarto,  extra  cloth,  with  320 
copper- plate  fiprures,  plain  and  colored,   $4  00. 

HUGHES'  INTRODUCTION  TO    THE   PRAC- 


TICE OF  AUSCULTATION  AND  OTHER 
MODES  OF  PHYSICAL  DIAGNOSIS  IN  DIS- 
EASES OF  THE  LUNGS  AND  HEART.  Se- 
cond edition  1  vol.  royal  liimc,  ex.  cloth,  pp. 
304,    $1  25. 

HOLLAND'S  MEDICAL  NOTES  AND  RE- 
FLECTIONS. From  the  third  London  edition. 
In   one  handsome  octavo  volume,  extra  cloth. 

m  50. 

HORNER'S  SPECIAL  ANATOMY  AND  HIS- 
TOLOGY. Eighth  edition.  Extensivly  revised 
and  modified.  In  two  large  octavo  volumes,  ex- 
tra cloth,  of  more  than  1000 pages,  with  over  309 
illustrations.    $6  00. 


HILLIER  (THOMAS),    M.D., 

Physician  to  the  Skin  Department  of  University  College  Hospital ;   Physician  to  the  Hospital  for  Sick 

Children,  &c.  &e. 

HANDBOOK  OF   SKIN   DISEASES,  FOR  STUDENTS  AND   PRACTI- 

TIONEKS.     In  one  neat  royal  ISmo.  volume,  of  about  300  pages,  with  two  plates;  extra  cloth, 

price  $2  25.     {Lately  j^ublished  ) 

From  the  Author's  Preface. 

'■  My  object  has  been  to  fiirni!«h  to  students  and  practitioners  a  trustworthy,  practical,  and  com- 
pendious treatise,  which  shall  comprise  the  g^reater  part  of  what  has  long  been  known  of  cutaneous 
diseases?,  and  of  what  ha*  been  more  recently  brought  to  light  by  English,  French,  and  German 
deniiato'ogists,  asVell  as  to  embody  the  most  important  results  of  my  own  experience  in  reference 
to  these  diseases  " 

The  author's  position  both  as  a  lecturer,  wr-ter,  and  practitioner  in  this  department  of  medicine, 
IS  a  guarantee  of  his  ability  to  accomplish  his  object  in  presenting  a  conden-ed  and  convenient 
manual,  which  shall  comprise  all  that  the  general  practitioner  requires  for  his  guidance. 

A  text  book  well  adapted  to  the  student,  and  the  information  contained  in  it  shows  the  author  to  be  au 
niveau  with  the  scientific  medicine  of  the  day, — London  Lancet,  Feb.  25,  1865. 


HAMILTON  (FRANK   H.),   M.  D., 

Professor  of  Surgery  in  the  Long  Island  College  Hospital. 

A   PRACTICAL   TREATISE    ON   FRACTURES   AND   DISLOCATIONS. 

Second  edition,  revised  and  improved.     In  one  large  and  handsome  octavo  volume,  of  over  750 

pages,  witii  nearly  300  illustrations,  extra  cloth,  $5  25. 

The  early  demand  for  a  new  edition  of  this  work  shows  that  it  has  been  successful  in  securing 
the  confidence  of  the  profession  as  a  standard  authority  for  consultation  and  reference  on  its  import- 
ant and  difficult  subject.  In  again  passing  it  through  the  press,  the  author  has  taken  the  opportu- 
nity In  revise  it  carefully,  and  introduce  whatever  improvements  have  been  sugg-ested  by  further 
experience  and  observation.  An  additional  chapter  on  Gun-shot  Fractures  will  be  found  to  adapt 
it  still  more  fully  to  the  exigencies  of  the  time. 

Among  themany  good  workersatsurgery  of  whom  I  a/Tections.  One  great  and  valuable  feature  in  the 
America  may  nowboast  not  the  least  is  Frank  Hast-  work  before  us  is  the  fact  that  it  comprises  all  the 
ings  Hamilton  ;  and  the  volume  before  us  is  (we  say  improvements  introduced  into  the  practice  of  both 
it  with  a  pang  of  wouiuled  patriotism)  the  best  and  |  English  and  American  surgery,  and  though  far  from 
handiest  book  on  the  subject  in  the  Erglish  Ian-  omitting  mention  of  our  continental  neighbors,  the 
guage.  It  is  in  vain  to  attempt  a  review  of  it;  i  author  by  no  means  encourages  the  notion — but  too 
nearly  as  vain  to  seek  for  any  sins,  either  of  com-  |  prevalent  in  some  quarters— that  nothing  is  good 
mission  or  omission.  We  have  seen  no  work  on  i  unless  imported  from  France  or  Germany.  The 
practical  surgery  which  we  wrould  sooner  recom-  i  latter  half  of  the  work  is  devoted  to  the  considera- 
mend  to  our  brother  surgeons,  especially  those  of  1  tion  of  the  various  dislocations  and  their  appropri- 
''  the  services,"  or  those  whose  practice  lies  in  dis-  \  ate  treatment,  and  its  merit  is  fully  equal  to  that  of 
tricts  where  a  man  has  necessarily  to  rely  on  his;  the  preceding  portion  —  TAe  iondon  Lancet,  May  5, 
own  unaided  resources.     Tlie  practitioner  will  find  1  I860. 

in  It  directions  for  nearly  every  possible  aceiuent,  [  ^  jg  emphatically  the  book  upon  the  subjects  of 
easily  found  and  comprehended;  and  much  pleasant  i  ,^i,ip|,  jj  treats,  and  we  cannot  doubt  that  it  will 
reading  for  him  to  mnse  over  in  the  after  confidera-  ,  continue  so  to  be  for  an  indefinite  period  of  time. 
ti<m<.tliiscase8.—£:rf?niMrgAA/«rf.Jo«rn  Feb. 1801.  !  yVhen  we  say,  however,  that  we  believe  it  will  at 

This  is  a  valuable  contribution  to  the  surgery  of  once  take  its  place  as  the  best  book  for  consultation 
most  important  affections, and  is  the  more  welcome,  j  by  the  practitioner ;  and  that  it  will  form  the  most 
inasimicli  as  at  the  present  time  we  do  not  possess  j  complete,  available,  and  reliable  guide  in  emergen- 
a  single  complete  treatise  on  Fractures  and  Dislo-  '  ciesof  every  natureconnected  with  itssubjects;  and 
cations  in  the  English  language.  It  has  remained  for  |  also  that  the  student  of  surgery  may  make  it  his  text- 
our  American  brother  to  produce  a  complete  treatise  ^  book  with  entire  confidence,  and  with  pleasure  also, 
upon  the  subject,  and  bring  together  in  a  convenient  from  its  agreeable  and  easy  style — we  think  our  own 
form  tliose  alterations  and  improvements  that  have  j  opini(m  may  be  gathered  as  to  its  value. —  Boston 
been  made  from  time  to  lime  in  tlie  treatment  of  these     Medital  and  SurgicalJournal, ^la.xc\\  1,  1S60. 


HODGE(HUGH    L.),   M.D., 
Professor  of  Midwifery  and  the  Diseases  of  Women  and  Children  in  the  University  of  Pennsylvania,  &;e. 

ON    DISEASES    PECULIAR   TO  WOMKN,  including  Displacements  of  the 

Uterus.     With  original  illustrations.     In  one  beautifully  printed  octavo  volume,  of  nearly  500 
pages,  extra  cloth.     $3  75. 


This  contribution  towards  the  elucidation  of  the 
pathology  and  treatment  of  some  of  the  diseases 
peculiar  to  women,  cannot  fail  to  meet  with  a  favor 
able  reception  from  the  medical  professiim.  The 
charafiter  of  the  particular  maladies  of  which  the 
work  before  us  treats;  their  frequency,  variety, and 
obscuiity:  theamountfit  maluiseand  even  of  actual 
suffering  by  which  thej'  are  invariably  attended; 
their  obstinacy,  the  dimculty  with  which  they  are 
overcome,  and  llcir  disposition  again  and  again  to 

The  illustrations,  which  are  all  original,  are  drawn  to  a  uniform  scale  of  one-half  the  natural  size 


recur — these,  taken  in  connection  with  the  entire 
Competency  of  the  author  to  render  a  correct  ac- 
".ount  of  their  nature  their  causes,  and  their  a|)pro- 
priate  managciiieni — his  ample  experience,  his  ma- 
tured judgment,  and  his  perfect  conscientiousness — 
invest  this  publication  with  an  interest  and  value  to 
which  few  of  the  medical  treatises  of  a  recent  ilate 
can  lay  a  stronger,  if,  perchance,  an  equal  claim. — 
Am.  Journ.  Med.  Sciences,  Jan.  1801. 


AND    SCIENTIFIC    PUBLICATIONS.  Vj 

HODGE  (HUGH    L.),    M.  D., 
Liito  PrnfesHor  of  Midwifery,  ic,  in  the  University  of  I'enngylvania. 

PRINCIPLES  AND  PRACTICE  OF  OPSTlfrillCS.     In  one  larfre  quarto 

Volume  of  over  .iriO  psfg^es,  wilh  one  hundred  and  firiy-i'i;^hl  fijjures  on  thirty  t  wo  txjaiiiiliilly  exe- 
cuted lithographic  plates,  and  nniiierous  wood-cuts  in  the  lexl.  $14  00.  {Just  Iisned.) 
This  Work',  etnbodying  the  results  of  an  extensive  practice  for  more  than  forty  years,  cannot  fail 
to  prove  of  the  ntino>t  value  to  all  who  are  eDf^aj^ed  in  this  department  oCmedicine.  The  author's 
position  as  one  of  che  hig-hest  authorities  on  the  >ul)ject  in  this  country  is  well  known,  and  llie  fruit 
of  his  ripe  experience  and  long  observation,  carefully  matured  and  elaborated,  must  serve  as  an 
invaluable  text-book  for  the  stii(li;nt  and  an  imfailing  counsel  for  the  practitioner  in  the  emergencies 
which  so  fre(|ucutly  arise  in  obstetric  practice. 

The  illustrations  form  a  novel  feature  in  the  work.  The  lithographic  plates  are  all  original, 
and  to  insure  their  absolute  accuracy  they  have  all  been  copied  from  photographs  taken  expressly 
lor  the  purpose.  In  ordinary  obstetrical  plates,  the  positions  of  the  Ibetus  are  represented  by  dia- 
grams or  sections  of  the  patient,  which  are  of  course  purely  imaginary,  and  their  correctness  is 
scarcely  more  than  a  matter  of  chance  wilh  the  artist.  Their  beauty  as  pictures  is  thereby  increased 
without  corresponding  utility  to  tlie  student,  as  in  practice  he  must  for  the  most  part  depend  for  his 
diagnosis  upon  the  relative  positions  of  the  fcptal  .-kull  and  the  pelvic  bones  of  the  mother.  It  is, 
therefore,  desirable  that  the  points  upon  which  he  is  in  future  to  rely,  should  form  the  basis  of  his 
in-truct!on,  and  consequently  in  the  preparation  of  these  illustrations  the  skeleton  has  alone  been 
U'sed.  and  the  aid  of  photography  invoked,  by  wliich  a  series  of  representations  has  been  secured  of 
the  strictest  and  most  rigid  accuracy.  It  is  easy  to  recognize  the  value  thus  added  to  the  very  full 
delai's  on  the  subject  of  the  Mkchanisat  of  Labour  with  which  the  .work  abounds 

it  may  be  added  that  no  pains  or  expense  have  been  spared  to  render  the  mechanical  execution  ot 
the  volume  worthy  in  every  respect  ol  the  character  and  value  of  the  teachings  it  contains. 


HA8ERSHON  (S.  O.),  M  .  D., 

Assistant  Physician  to  and  Lectufer  on  Materia  Mediea  and  Therapeutics  at  Guy's  Hospital,  &C. 

PATHOLOGICAL   AND   PRACTICAL  OBSERVATIONS  ON  DISEA.SES 

OF  THE  ALIMENTARY  CANAL,  (ESOPHAGUS,  STOMACH,  C.-ECUM,  AND  INTES- 
TINES. With  illustrations  on  wood.  In  one  handsome  octavo  volume  of  312  pages,  extra 
cloth.    $2  50. 


HOBLYN  (RICHARD  D.),  M.  D. 
A  DICTIONARY  OF  THE  TERMS  USED  IN  MEDICINE   AND  THE 

COLLATERAL  SCIENCES.  A  new  American  edition.  Revised,  with  numerous  Additions, 
by  Isaac  Hays,  M.  D.,  editor  ol  the  "  American  Journal  of  the  Medical  Sciences."  In  one  large 
royal  12mo.  volume,  cloth,  of  over  500  double  columned  pages.     $1  50 


To  both  practitioner  and  student,  we  recommend 
this  dictionary  as  being  convenient  in  size,  accurate 
in  definition,  and  sufficiently  full  and  complete  for 
ordinary  consultation  — Charleston  Med.  Journ. 

We  know  of  no  dictionary  better  arranged  and 
adapted.  Itisnotencumbered  with  theobsoleteterms 
of  a  bygone  age,  but  it  contains  all  that  are  now  in 


use  ;  embracing  everydepartmcnt  of  medical  science 
down  to  the  very  latest  date. — Weslern  Lancet. 

Hoblyn's  Dictionary  has  long  been  a  favorite  with 
us.  It  is  the  best  book  of  definitions  we  have,  and 
ought  always  to  be  upon  the  student's  table. — 
Southern  Med.  and  Surg .  Journal . 


JONES  (T.   WHARTON),   F.  R.  S., 

Professor  of  Ophthalmic  Medicine  and  Surgery  in  University  College,  London,  &.C. 

THE  PRINCIPLES  AN  IT  PRACTICE  OF   OPHTHALMIC    MEDICINE 

AND  SURGERY.  With  one  hundred  and  seventeen  illustrations.  Third  and  revistid  Ameri- 
can, with  additions  from  the  seconc  London  edition.  In  one  handsome  octavo  volume,  extra 
cloth,  ol  455  pages.     $3  25. 

Seven  j^ears  having  elapsed  since  the  appearance  of  the  last  edition  of  this  standard  work,  very 
considerable  additions  have  been  found  neoess^iry  to  adapt  it  ihoioughly  to  the  advance  of  ophthal- 
mic science.  The  introduction  of  the  ophlhalnioscopi!  has  resulted  in  adding  greatly  to  our  know- 
ledge of  the  pathology  of  the  diseases  of  the  eye,  particularly  of  its  more  deeply  seated  tissue>,  and 
corresponding  im|)roveinents  in  medical  treatment  and  operative  procedures  have  been  introduced. 
All  these  matters  the  editor  has  endeavoured  to  add,  bearing  in  mind  the  character  of  the  volume  as  a 
condensed  and  practical  manual  To  accommodate  this  unavoidable  increase  in  the  size  of  the  work, 
its  form  has  been  changed  from  a  duodecimo  to  an  octavo,  and  it  is  presented  as  worthy  a  continu- 
ance of  the  favour  which  has  been  bestowed  on  former  editions. 

A  complete  series  of  "test-types"  for  examining  the  accommodating  power  of  the  eye,  will  be 
found  au  important  and  useful  addition. 


JONES  (C.  HANDFIELD),  F.R.  S.,  &.   EDWARD   H.   SIEVEKING,   M.D., 

Assistant  Physicians  and  Lecturers  in  St.  Mary's  Hospital,  London. 

A  MANUAL  OF  PATHOLOGICAL   ANATOMY.    First  American  Edition, 

Revised.     With  three  hundred  and  ninety-seven  handsome  wood  engravings.    In  one  large  and 

beautiful  octavo  volume  of  nearly  750  pages,  extra  cloth.     $3  50. 

As  a  concise  text-book,  containing,  in  a  condensed  |  obliged  to  glean  from  a  great  number  of  monographs, 
form,  a  complete  outline  of  what  is  known  in  the  '  and  the  field  was  soexlensivethat  but  fewcultivated 
domain  of  Pathological  Anatomy,  it  is  perliaps  the  I  it  with  any  degree  of  success.  As  a  simple  work 
best  work  in  che  English  languaore.  Its  great  merit  of  reference,  therefore,  it  is  of  great  value  to  the 
consists  in  its  completeness  and  brevity,  and  in  this  student  of  pathologieal  anatomy",  and  sliould  be  m 
respect  if  supplies  a  great  desideratum  in  our  lite-  e.very  physician's  library.— ITasrern  Loncel. 
rature.    Heretofore  the  student  of  pathology  was  | 


20 


HENKY   C.   LEA'S  MEDICAL 


KIRKES  (WILLIAM 

Demonstrator  of  Morbid  Anatomy  a 

A   MANUAL   OF    PHYSIOLOGY. 

improved  London  edition.    Witii  two  liundred 

12nio.  volume,  extra  cloth,     pp.  5S6.     $2  25. 

Tins  is  a  new  and  very  much  improved  edition  of 
Dr.  Kirkes'  well-known  Handbook  of  Physiolog:y. 
It  combines  conciseness  with  completeness,  and  is, 
tlierefore,  admirably  adapted  for  ctmsultation  by  the 
busy  practitioner. — Dublin  Quarterly  Journal. 

One  of  the  very  best  handbooks  of  Physiology  we 
possess — presenting  just  such  an  outline  of  the  sci- 
ence as  the  student  requires  during  his  attendance 
upon  a  course  of  lectures,  or  for  reference  whilst 
preparing  for  examination.— j4»n.  Medical  Journal . 

Its  excellence  is  in  its  compactness,  its  clearness, 


SENHOUSE),   M.  D., 

t  St.  Bartholomew's  Hospital,  &c. 

A  new  Americarij  from  the  third  and 
illustrations.    In  one  large  and  handsome  royal 

and  its  carefully  cited  authorities.  It  is  the  most 
convenientoftext-books.  These  gentlemen,  Messrs. 
Kirkes  and  Paget,  have  the  gift  of  telling  us  what 
we  want  to  know,  without  thinking  it  necessary 
to  tell  us  all  they  know. — Boston  Med  and  Surg. 
Journal. 

For  the  student  beginning  this  study,  and  the 
practitioner  who  has  but  leisure  to  refresh  his 
memory,  this  book  is  invaluable,  as  it  contains  all 
that  it  is  important  to  know. — Charleston  Mtd. 
Journal. 


KNAPP'S  TECHNOLOGY  ;  or.  Chemistry  applied 
to  the  Arts  and  to  Manufactures.  Edited  by  Dr. 
Ronalds,  Dr.  Richardson,  and  Prof.  VV.  R. 
Johnson.  In  two  handsomt  8vo.  vols.,  extra  cloth, 
with  about  500  wood- engravings.    $6  00. 


LAYCOCK'S  LECTURES  ON  THE  PRINCf.- 
PLES  AND  METHODS  OF  MEDICAL  OB- 
SERVATION AND  RESEARCH.  For  the  Use 
of  Advanced  Students  and  Junior  Practitioners. 
In  one  royal  l'2mo.  volume,  extra  cloth.  Price $1. 


LALLEMAND  AND  WILSON. 
A    PRACTICAL    TREATISE    ON    THE    CAUSES,    SYMPTOMS,    AND 

TREATMENT  OF  SPEKMATORRHCEA.     By  M.  Lallemand.    Translated  and  edited  by 

Henry  J   McDougall.     Third  American  edition.    To  which  is  added ON  DISEASES 

OF  THE  VESlCULiE  SEMINALES;  and  their  associated  organs.  With  special  refer- 
ence to  the  Morbid  Secretions  of  the  Prostatic  and  Urethral  Mucous  Membrane.  By  Marris 
Wilson,  M.  D.    In  one  neat  octavo  volume,  of  about  400  pp.,  extra  cloth.  $2  75. 


LA    ROCHE  (R.),    N^.  D.,  &c. 
YELLOW  FEVER,  considered  in  its  Historical,  Pathological,  Etiological,  and 

Therapeutical  Relations.  Including  a  Sketch  of  the  Disease  as  it  has  occurred  in  Philadelphia 
from  1699  to  1854,  with  an  examination  of  the  connections  between  it  and  the  fevers  known  under 
the  same  name  in  other  parts  of  temperate  as  well  as  in  tropical  regions.  In  two  large  and 
handsome  octavo  volumes  of  nearly  1500  pages,  extra  cloth.     $7  00. 


We  have  not  time  at  present,  engaged  as  we  are, 
by  day  and  by  night,  in  the  work  of  combating  this 
very  disease,  now  prevailing  in  our  city,  to  do  more 
than  give  this  cursory  notice  of  what  we  consider 
as  undoubtedly  the  most  able  and  erudite  medical 
publication  our  country  has  yet  produced.  But  in 
view  of  the  startlintr  fact,  that  this,  the  most  malig- 
nant and  unmanageable  disease  of  modern  times, 
has  for  several  years  been  prevailing  in  our  country 
to  a  greater  extent  than  ever  before;  that  it  is  no 


longer  confined  to  either  large  or  small  cities,  but 
penetrates  country  villages,  plantations,  and  farm- 
houses; that  it  is  treated  with  scarcely  better  suc- 
cess now  than  thirty  or  forty  years  ago ;  that  there 
is  vast  mischief  done  by  ignorant  pretenders  to  know- 
ledge in  regard  to  the  disease,  and  in  view  of  the  pro- 
bability that  a  majority  of  southern  physicians  will 
be  called  upon  to  treat  the  disease,  we  trust  that  this 
able  and  comprehensive  treatise  will  be  very  gene- 
rally read  in  the  south. — Memphis  Med.  Recorder. 


BY  THE  SAME  AUTHOR. 


PNEUMONIA ;  its  Supposed  Connection,  Pathological  and  Etiological,  with  Au- 
tumnal Fevers,  including  an  Inquiry  into  the  Existence  and  Morbid  Agency  of  Malaria.  In  one 
handsome  octavo  volume,  extra  cloth,  of  500  pages.    $3  00. 


LEHMANN   (C.  G.) 
PHYSIOLOGICAL    CHEMISTRY.     Translated  from  the  second  edition   by 

George  E.  Day,  M.  D.,  F.  R.  S.,  &c.,  edited  by  R.  E.  Rogers,  M.  D.,  Professor  of  Chemistry 
in  the  Medical  Department  of  the  University  of  Pennsylvania,  with  illustrations  selected  from 
Funke's  Atlas  of  Physiological  Chemistry,  and  an  Appendix  oi'  plates.  Complete  in  two  large 
and  handsome  octavo  volumes,  extra  cloth,  containing  1200  pages,  with  nearly  two  hundred  illus- 
trations. $6  00. 
The  work  of  Lehmann  stands  unrivalled  as  the  I      The  most  important  contribution  as  yet  made  to 

most  comprehensive  book  of  reference  and  informa-  |  Physiological  Chemistry. — Am.  Journal  Med.  Set- 

tion  extant  on  every  branch  of  the  subject  on  w^hich  I  inces,  Jan.  1856. 

it  treats. — Edinburgh  Journal  of  Medical  Science.  \ 

BY  THE  same  AUTHOR. 

MANUAL  OF  CHEMICAL   PHYSIOLOGY.      Translated  from  the  German, 

with  Notes  and  Additions,  by  J.  Cheston  Morris,  M.  D.,  with  an  Introductory  Essay  on  Vital 
Force,  by  Professor  Samuel  Jackson,  M.  D.,  of  the  University  ol  Pennsylvania.  With  illus- 
trations on  wood.     In  one  very  handsome  octavo  volume,  extra  cloth,  of  336  pages.    $2  25. 

LUDLOW  (J.   L.),   M.  D. 
A   MANUAL   OF    EXAMINATIONS   upon   Anatomy,   Physiology,   Surgery, 

Practi(-e  of  Medicine,  Ob:^tetrics,  Materia  Medicu,  Chemistry,  Pharmacy,  and  Therapeutics.     To 
which  is  added  a  Medical  Formulary.     Third  edition,  thoroughly  revised  and  greatly  extended 
and  enlarged.     With  370  illustrations.     In  one  handsome  royal  12mo.  volume,  ol  Sltj  large 
page?,  extra  cloth,  $3  '^ft. 
We  know  of  no  belter  companion  for  the  student  1  crammed  into  his  head  by  the  various  professors  to 

durinj;  the  hours  spent  in  the  lecture  room,  or  to  re-     whom  he  is  compelled  to  listen. — Western  LoMCd, 

fresh,  at  a  glance,  his  memory  of  the  various  topics  |  May,  1857. 


AND    SCIENTIFIC    PUBLICATIONS. 


21 


LYONS  (ROBERT   D.),    K.  C.  C, 

Late  Pathologist  in-cliicf  to  tlie  Britisli  Ariny  in  the  Crimea,  !cc. 

A  TREATISE  ON  FEVER;  or,  selections  from  a  course  of  Lectures  on  Fever. 

Being:  part  of  a  course  of  Theory  and  Prtictice  of  Medicine.     lu  one  neat  octavo  volume,  of  362 
pages,  extra  cloth;  $2  25. 


This  is  iin  a{|inir;il)le  work  upon  the  most  remark- 
able and  moBt  important  class  of  dismises  to  which 
mankind  are  liable. — Med.  Journ.  of  N.  Carolina. 
May,  1861. 

We  have  great  pleasure  in  recommending  Dr. 


Lyons'  work  on  Fever  to  the  attention  of  the  pro- 
fession. It  is  a  work  which  cannot  fail  to  enhance 
the  author's  previous  well-earned  reputation,  as  a 
liligent,  careful,  and  accn'ate  observer. — Britisk 
Med.  Journal,  March  2,  1661. 


MONTGOMERY  (W.  F.),   M.  D.,   M.  R.  I.  A.,  Sec, 

Professor  of  Midwifery  in  the  King  and  Queen's  College  of  Pliysicians  in  Ireland,  &c. 

AN  EXPOSITION  OF  THE  SIGNS  AND  SYMPTOMS  OF  PREGNANCY. 

With  some  other  Paperis  on  Subjects  connected  with  Midwifery.  From  the  second  and  enlarged 
English  edition.  With  two  exquisite  colored  plates,  and  numerous  wood-cuts.  In  one  very 
handsome  octavo  volume,  extra  cloth,  of  nearly  600  pages.     .$3  75. 


A  book  unusually  rich  in  practical  suggestions. — 
Am  Journal  Med.  Sciences,  Jan.  1857. 

These  several  subjects  so  interesting  in  them- 
Belves,  and  so  important,  every  one  of  them,  to  the 
most  delicate  and  precious  of  social  relations,  con- 
ti oiling  often  the  honor  and  domestic  peace  of  a 
family,  the  legitimacy  of  offspring,  or  the  life  of  its 
parent,  are  all  treated  with  an  elegance  of  dicticm, 
fulness  of  illustrations,  acutenessand  justice  of  rea- 
Doning,  unparalleled  in  obstetrics,  and  unsurpassed  in 
medicine.    The  reader's  interest  can  never  flag,  so 


fresh,  and  vigorous,  and  classical  is  our  author's 
style;  and  one  forgets,  in  tlie  renewed  charm  of 
>^very  page,  that  it,  and  every  line,  and  every  word 
has  been  weighed  and  reweighed  through  years  of 
preparation;  that  this  is  of  all  others  the  book  of 
Obstetric  Law,  on  each  of  its  several  topics;  on  all 
points  connected  with  pregnancy,  to  be  everywhere 
received  as  a  manual  of  special  jurisprudence,  at 
once  announcing  fact,  affordingargument,  establish- 
ing precedent,  and  governing  alike  the  juryman,  ad- 
vocate, and  judge.— iV.  A.  Med.-Chir.  Review. 


MEIGSCCHARLES  D.),  M.  D., 

Lately  Professor  of  Obstetrics,  &c.  in  the  Jefferson  Medical  College,  Philadelphia. 

OBSTETRICS :   THE  SCIENCE  AND  THE  ART.     Fourth  edition,  revised 

and  improved.   With  one  hundred  and  twenty-nine  illustrations.  In  one  beautifully  printed  octav* 
Volume,  of  seven  hundred  and  ttiirty  large  pages,  extra  cloth,  $5  00. 

From  the  Author's  Preface. 

"  [n  this  edition  I  have  endeavored  to  amend  the  work  by  changes  in  its  form  ;  by  careful  cor- 
rections of  many  expressions,  and  by  a  few  omissions  and  some  additions  as  to  the  text. 

"The  Student  will  find  that  I  have  recast  the  article  on  Placenta  Prsevia.,  which  I  was  led  to  do 
out  of  my  desire  to  notice  certain  new  modes  of  treatment  which  I  regarded  as  not  only  ill  founded 
as  to  the  philosophy  of  our  department,  but  dangerous  to  the  people. 

"  In  changing  the  form  of  my  work  by  dividing  it  into  paragraphs  or  sections,  numbered  from  1 
to  959,  I  thought  to  present  to  the  reader  a  common-place  book  of  the  whole  volume  Such  a  table 
of  contents  ought  to  prove  both  convenient  and  useful  to  a  Student  while  attending  public  lectures." 

A  work  which  has  enjoyed  so  extensive  a  reputation  and  has  been  received  with  such  general 
favor,  requires  only  the  assurance  that  the  author  has  labored  assiduously  to  embody  in  his  new 
edition  whatever  has  been  found  necessary  to  render  it  full)'  on  a  level  with  the  most  advanced 
&tate  of  the  subject.  Both  as  a  text-book  for  the  student  and  as  a  reliable  work  of  reference  for 
the  practitioner,  it  is  therefore  to  be  hoped  that  the  volume  "will  be  found  worthy  a  continuance  of 
the  confidence  reposed  in  previous  editions. 

BY   THE  SAME  AUTHOR. 

WOMAN:  HER  DISEASES  AND  THEIR  REMEDIES.     A  Series  of  Lee 

tures  to  his  Class.     Fourth  and  Improved  edition.     In  one  large  and  beautifully  printed  octave 


$5  00. 


volume,  extra  cloth,  of  over  700  page 

In  other  respects,  in  our  estimation,  too  much  can- 
not be  said  in  praise  of  this  work.  It  abounds  with 
beautiful  passages,  and  for  conciseness,  for  origin- 
ality, and  for  all  that  is  commendable  in  a  work  on 
the  diseases  of  females,  it  is  not  excelled,  and  pro- 
bably not  equalled  in  the  English  language.  On  the 
whole,  we  know  of  no  worK  on  the  diseases  of  wo- 
men which  we  can  so  cordially  commend  to  the 
etudent  und  practitioner  as  the  one  before  us. — Ohio 
Med.  and  Surg.  Journal. 

The  body  of  the  book  is  worthy  of  attentive  con- 
sideration, and  is  evidently  the  production  of  a 
.clever,  thoughtful,  and'sagaeious  physician.  Dr. 
Meigs's  letters  on  the  diseases  of  the  external  or- 
gans, contain  many  interesting  and  rare  cases,  and 
many  instructive  observations.  We  take  our  leave 
of  Dr.  Meigs,  with  a  high  opinion  of  his  talents  and 
originality.— r/i(j  British  and  Foreign  Medico-Chi- 
rurgical  Review. 

Every  chapter  is  replete  with  practical  instruc- 
tion, and  bears  the  impress  of  being  the  composition 
of  an  acute  and  experienced  mind.  There  is  a  terse- 
ness, and  at  the  same  tune  an  accuracy  in  his  de- 
•erifi  tion  of  symptoms,  and  in  the  rules  for  diagnosis, 


which  cannot  fail  to  recommend  the  volume  to  the 
attention  of  the  reader. — Ranking's  Abstract. 

It  contains  a  vast  amount  of  practical  knowledge, 
Dy  one  who  has  accurately  observed  and  retained 
the  experience  of  many  years. — Dublin  Quarterly 
Journal . 

Full  of  important  matter,  conveved  in  a  ready  and 
agreeaule  manner.— Si. Louis  Med.  and  Surg.  Jour. 

There  is  an  off-hand  fervor,  aglow,  and  a  warm- 
.leartedness  infecting  the  eff  irt  of  Dr.  Meigs,  which 
is  entirely  captivating,  and  which  absolutely  hur- 
ries the  reader  through  from  be"inniug  to  end.  Be- 
sides, the  book  teems  with  solid  instruction,  and 
It  shows  the  very  highest  evidence  of  ability,  viz., 
the  clearness  with  which  the  information  is  pre- 
sented. We  know  of  no  better  test  of  one's  under- 
uauding  a  subject  than  the  evidence  of  the  power 
.)f  lucidly  explaining  it.  The  most  elementary,  as 
well  as  the  obscurest  subjects,  under  the  pencil  of 
I'rof.  Meigs,  are  isolated  and  made  to  stand  out  la 
sucn  bold  relief,  as  to  produce  distinct  impression* 
upon  the  mind  and  memory  of  the  reader.  —  Tki 
Charleston  Med.  Journal, 


HENRY  C.   LEA'S   MEDICAL 


MEIGS  (CHARLES  D.)   M.  D., 

Lately  Professor  of  Obstetrics,  &c.,  in  Jefferson  Medical  College,  Philadelphia. 

ON    THE    NATURE,    SIGNS,    AND    TREATMENT    OF    CHILDBED 

FEVER.     In  a  Series  of  Letters  addressed  to  tlie  Students  of  his  Class.    In  one  handsome 
octavo  volume,  extra  cloth,  of  365  pages.     $2  00, 

The  instructive  and  interesting  author  of  this  I  lectable  book.  *  *  *  Tliis  treatise  upon  child- 
work,  wliose  previous  labors  have  placed  his  coun-  bed  fevers  will  have  an  extensive  sale,  being  des- 
tryinen  under  deep  and  abiding  obligations,  again  lined,  as  it  deserves,  to  find  a  place  in  the  library 
challenges  their  admiration  in  the  fresh  and  vigor-  of  every  practitioner  whoscorns  tolag  in  the  rear. — 
ous,  attractive  and  racy  pages  before  as.   It  is  a  de-  '  Nashville  Journal  of  Medicine  and  Surgery. 


MACLISE  (JOSEPH),    SURGEON. 
SURGICAL  ANATOMY.     Forming  one  volume,   very  Jarge  imperial   quarto . 

With  sixty-eight  large  and  splendid  Plates,  drawn  in  the  best  style  and  beautifully  colored.  Con- 
taining one  hundred  and  ninety  Figures,  many  ol  them  the  size  ol  life.  Together  with  copious 
and  explanatory  letter-press.  Strongly  and  handsomely  bound  in  extra  cloth,  being  one  of  the 
cheapest  and  best  executed  Surgical  works  as  yet  issued  in  this  country.    $14  00. 

These  plates  will  be  found  of  the  highest  practical  value,  either  for  cousulta- 
tion  in  emergencies  or  to  refresh  the  recollections  of  the  dissecting  room. 

*^*  The  size  of  this  work  prevents  its  transmission  through  the  post-ortice  as  a  whole,  but  those 
who  desire  to  have  copies  forwarded  by  mail,  can  receive  them  in  five  parts,  done  up  in  stout 
wrappers.     Price  $12  00. 

A  work  which  has  no  parallel  in  point  of  accu- 
racy and  cheapness  in  the  English  language. — N.  Y . 
Journal  of  Medicine. 

We  are  extremely  gratified  to  announce  to  th« 
profession  the  completion  of  this  truly  magnificent 
work,  which,  as  a  whole,  certainly  stands  unri- 
valled, both  for  accuracy  of  drawing,  beauty  of 
coloring,  and  all  the  requisite  explanations  of  the 
subject  in  hand. — The  Nev  Orleans  Medical  and 
Surgical  Journal. 


One  of  the  greatest  artistic  triumphs  of  the  age 
in  Surgical  Anatomy. — British  American  Medical 
Journal. 

No  practitioner  whose  means  will  admit  should 
fail  to  possess  it. — Ranking's  Abstract. 

Too  much  cannot  be  said  in  its  praise;  indeed, 
we  have  not  language  to  do  it  justice. — Ohio  Medi- 
tal  and  Surgical  Journal. 

The  most  accurately  engraved  and  beautifully 
colored  plates  we  have  ever  seen  in  an  American 
book — one  of  the  best  and  cheapest  surgical  works 
ever  published. — Buffalo  Medical  Journal. 

It  is  very  rare  that  so  elegantly  printed,  so  well 
illustrated,  and  so  useful  a  work,  is  offered  at  so 
moderate  a  price. — Charleston  Medical  Journal. 

Its  plates  can  boast  a  superiority  which  places 
them  almost  beyond  the reachof  competition. — Medi- 
tal  Examiner. 

Country  practitioners  will  find  these  plates  of  im- 
mense value — iV.  Y.  Medical  Gazette. 


This  is  by  far  the  ablest  work  on  Surgical  Ana- 
tomy that  has  come  under  our  observation.  W« 
know  of  no  other  work  that  would  justify  a  stu- 
dent, in  any  degree,  for  neglect  of  actual  dissec- 
tion. In  tluise  sudden  emergencies  that  so  often 
arise,  and  which  require  theinstantaneouscommand 
of  minute  anatomical  knowledge,  a  work  of  this  kind 
keeps  the  lietails  of  the  dissecting-room  perpetually 
fresh  in  the  memory  .—TA«  Western  Journal  of  Medi- 
cine and  Surgery. 


MILLER  (HENRY),  M.  D., 

Professor  of  Obstetrics  and  Diseases  of  Women  and  Children  in  the  University  of  Louisville. 

PRINCIPLES  AND  PRACTICE  OF  OBSTETRICS,  &c. ;  including  the  Treat- 

ment  of  Chronic  Inriammation  of  the  Cervix  and  Body  of  the  Uterus  considered  as  a  fre(|uent 
cause  of  Abortion.  With  about  one  hundred  illustrations  on  wood.  In  one  very  handsome  oc- 
tavo volume,  of  over  600  pages,  extra  cloth.     $3  75. 

We  congratulate  the  author  that  the  task  is  done. 
We  Congratulate  him  that  he  hasgiven  to  the  nierli- 
cal  public  a  work  which  will  secure  for  him  a  high 


and  permanent  position  amcmg  the  standard  auth 
rities  on  the  principles  and  practice  of  obstetrics. 
Congratulations  are  not  less  due  to  the  medical  pro- 
fession of  this  country,  on  the  acquisition  of  a  trea- 
tise embodying  the  results  of  the  studies,  reflections, 
and  experience  of  Prof.  Miller. — Buffalo  Medical 
Journal. 

In  fact,  this  volume  must  take  its  place  am(m^  the 
standard  systematic  treatises  on  obstetrics;  a  posi- 


tion to  which  its  merits  justly  entitle  it. — The  Cin- 
cinnati Lancet  and  Observer. 

A  most  respectable  and  valuable  addition  to  our 
home  meilical  literature,  and  one  reflecting  credit 
alike  on  the  author  and  ihe  institution  to  which  he 
is  attached.  The  student  will  find  in  this  work  a 
most  useful  guide  to  his  studies;  the  country  prac- 
titi<mer,  rusty  in  his  reading,  can  obtain  from  its 
pages  a  fair  resume  of  the  modern  literature  of  the 
science;  and  we  hope  to  see  this  American  produc- 
ti<m  generally  consulted  by  the  profession. —  Vu. 
Med.  Journal. 


MACKENZIE   (W.),    M.D.,  • 

Surgeon  Oculist  iii  Scotland  in  ordinary  to  Her  Majesty,  &c.  &c. 

A  PRACTICAL  TREATISE  ON   DISEASES   AND  INJURIES  OF   THE 

EYE.  To  which  is  prefixed  an  Aiiatomieal  Introduction  txplunalory  o(  a  Horizontal  Section  ol 
the  Human  Eyeball,  by  Tuomas  Wjiarton  Jones,  F.  R.  S.  From  ihe  Fourth  Revised  and  En- 
larged London  Edii  ion.  With  Notes  and  Additions  by  Addineli.  Hkwson,  M.  D.,  Surgeon  to 
Wills  Ho>pilal,  &c.  &c.  In  one  very  large  and  handsome  octavo  Volume,  extra  cloth,  with  plates 
and  numerous  wood-cuts      $6  50. 


The  trentlse  of  Dr.  Mackenzie  indiK[iutably  holds 
the  firstplace,  and  foriris,  in  respect  o(  learning  and 
research,  an  lOncyclop^dia  unequalled  in  extent  by 
»ny  other  work  of  the  kind, either  ICnglishor  foreign    I 
—Dixon  on  Diseases  of  the  Eye. 


We  consider  it  the  duty  of  every  one  who  has  the 
love  of  his  profession  and  the  welfare  of  his  patient 
at  heart,  to  maki  himself  familiar  with  this  the  ment 
complete  work  in  the  Knglish  language  upon  thedii- 
euses  of  the  eye. —  Med.  Timesand  Oazetl*. 


AND    SCIENTIFIC    PUBLICATIONS. 


23 


MILLER  (JAMES),  F.  R.  S.  E., 
Professor  of  Surgery  in  the  University  of  IvJinburgh,  &c. 

PRINCIPLES  OF  SURGERY.     Fourth  American,  from  the  third  and  revised 

Edinburgh  edition.    In  one  large  and  very  beautiful  volume,  extra  cloth,  of  700  pages,  with 
two  hundred  and  forty  illustrations  on  wood.    $3  75. 

BY   THE  SAME  AUTHOR. 

THE    PRACTICE   OF   SURGERY.      Fourth  American  from  the  last  Edin- 

burgh  edition.     Revised  by  the  Amerifnn  editor.     Illustrated  by  three  hundred  and  .sixtv-four 
engravings  on  wood.     In  one  large  oeiuvo  volume,  extra  *lolh,  of  nearly  700  pages.     $3  7.5. 

No  encomium  of  ours  could  add  to  the  popularity 
of  Miller's  Surgery .  Its  reputation  in  this  country 
is  unsurpassed  by  that  of  any  other  work,  and,  when 
luken  in  conneetion  with  the  autlior's  Principles  of 
Svrgery,  constitutes  a  whole,  without  reference  to 
which  no  conscientious  surgeon  would  be  willing  to 
practice  his  art. —  Southern  Med.  and  Surg.  .Journal. 

1 1  18  seldom  that  two  volumes  have  ever  made  so 


proi'riund  an  impression  in  so  short  a  time  as  the 
"  Principles"  and  the  "  Practice"  of  Surgery  by 
Mr.  Miller — or  so  richly  merited  the  reputation  they 
have  acquired.  The  author  is  an  eminently  sensi- 
ble, practical,  and  well-informed  man,  who  knows 
exactly  what  he  is  talking  about  and  exactly  how  to 
talk  it. — Kentucky  Medical  Recorder. 

By  the  almost  unanimous  voice  of  the  profession. 


his  works,  both  on  the  principles  and  practice  of 
surgery  have  been  assigu'd  the  highest  rank.  If  wc 
were  limited  to  but  one  work  on  surijery,  that  one 
should  be  .Miller's,  a.?  we  regard  it  as  superior  to  all 
others. — St.  Louis  Med.  and  Surg.  .Tournal. 

The  author  has  in  this  and  his  "  Principles,"  pre- 
sented to  the  profession  one  of  the  most  complete  and 
reliable  systems  of  Surgery  extant.  His  style  of 
writing  is  original,  impressive,  and  engaging,  ener- 
getic, concise,  and  lucid.  Few  have  the  faculty  of 
condensing  so  much  in  small  space,  and  at  the  same 
time  so  persistently  holding  theattention.  Whether 
as  a  text-book  tor  students  or  a  book  of  reference 
for  practitioners,  it  cannot  be  too  strongly  recom- 
mended.— Soutkern  Journal  of  Med.  and  Physical 
Sciences. 


MORLAND  (W.  W.),   M.   D., 

Fellow  of  the  Massachusetts  Medical  Society,  &c. 

DISEASES  OF  THE  URINARY  ORGANS;  a  Compendium  of  their  Diagnosis, 


Pathology,  and  Treatment.     With  illustrations 
about  600  pages,  extra  cloth.     $3  -50. 

Taken  as  a  whole,  we  can  recommend  Dr.  Mor- 
land's  compendium  as  a  very  desirable  addition  to 
the  library  of  every  medical  or  surgical  practi- 
tioner.— Brit  andFor.  Med.-Chir.  Rev.,  April,  1859. 

Every  medical  practitioner  whose  attention  has 
been  to  any  extent  attracted  towards  the  class  of 
diseases  to  which  this  treatise  relates,  must  have 
often  and  sorely  experienced  the  want  of  some  full, 
yet  concise  recent  compendium  to  which  he  could 

BY  THE  SAME   AUTHOR. 

THE  MORBID  EFFECTS  OF  THE   RETENTION  IN  THE   BLOOD  OP 

THE  ELEMENTS  OF  THE  UiUNARY  SECRETJON.  Being  the  Disserlation  to  which  the 
Fiske  Fund  Prize  was  awarded,  July  11,  1861.  In  one  small  octavo  volume,  S3  pages,  extra 
cloth.     75  cents. 


In  one  large  and  handsome  octavo  volume,  oi 

refer.  This  desideratum  has  been  supplied  by  Dr. 
Morland,  and  it  has  been  ably  done.  He  has  placed 
before  us  a  full,  judicious,  and  reliable  digest. 
Each  subject  is  treated  with  sufficient  minuteness, 
yet  in  a  succinct,  narrational  style,  su(;h  as  to  reider 
the  wori  one  of  great  interest,  and  one  which  will 
prove  in  the  highest  degree  useful  to  the  general 
practitioner. — N.  Y.Journ.  of  Medicine^ 


MAYNE'S  DISPENSATORY  AND  THERA- 
PEUTICAL REMEMBRANCER.  With  every 
Practical  Formula  contained  in  the  three  British 

I  Pharmacopceias  Edited,  with  the  addition  of  the 
Formulae  of  the  U.  S.  PharmaciipcBia,  by  R.  E. 
'Jris'B'itHjM.D    1  12mo.  vol.ex.cl.,.'?OOnp   7.5  n. 


MALGAIGNE'S  OPERATIVE  SURGERY,  based 

on  Normal  and  Pathological  Anatomy.  Trans- 
lated from  the  Frcncli  by  Fredekick  Brittan, 
A.  B.,M.  D.  AVith  numerous  illustrations  on  wood. 
In  one  handsome  octavo  volume,  extra  cloth,  of 
nearlv  six  hundred  pages.    S2  .10. 


NELIGAN  (J.    MOORE),  M.  D.,  M.  R.  I.  A.,  «ic. 
ATLAS  OF  CUTANEOUS  DISEASES.     In  one  beautiful  quarto  volume,  extra 

cloth,  with  splendid  colored  plates,  presenting  nearly  one  hundred  elaborate  representations  of 

disease.     $5  50. 

This  beautiful  volume  is  intended  as  a  complete  and  accurate  representation  of  all  the  varieties 
of  Diseases  o(  the  Skin.  While  it  can  be  consulted  in  conjunction  with  any  work  on  Practice,  it  has 
especial  reference  to  the  author's  <'  Treatise  on  Diseases  of  the  Skin,"  so  favorably  received  by  the 
profession  some  years  since.  The  publishers  feel  justified  in  saying  that  few  more  beautifully  exe- 
cuted plates  have  ever  been  presented  to  the  profession  of  this  country. 


Neligan's  Atlas  of  Cutaneous  Diseases  supplies  a 
long  existent  desideratum  much  fell  by  the  largest 
class  of  our  profession.  It  presents,  in  quarto  size, 
16  plates,  each  containing  from  3  to  6  figures,  and 
forming  in  all  a  total  of  no  distinct  representations 
of  the  different  species  of  skin  affect,i(ms,  grouped 
together  in  genera  or  families.  The  illustrations 
have  been  taken  from  nature,  and  have  lieen  copied 
with  such  fidelity  that  they  present  a  striking  picture 
of  life;  in  which  the  reduced  scale  aptly  serves  to 

BY  THE  SAME  AUTHOR. 

A    PRACTICAL    TREATISE    ON    DISEASES  OF   THE  SKIN.     Fourth 
American  edition.    In  one  neat  royal  r2mo.  volume,  extra  cloth,  of  334  pages,    fl  50. 


give,  at  a  coup  d'cEil,  the  remarkable  peculiarities 
of  each  inilividual  variety.  And  while  thus  the  dis- 
ease is  rendered  more  definable,  there  is  yet  no  loss 
of  proportion  incurred  by  the  necessary  concentra- 
tiim.  Each  figure  is  highly  colored,  and  so  truthful 
has  rhe  artist  been  that  the  most  fastidous  observer 
ccuild  not  justly  take  exception  to  the  correctness  of 
the  execution  of  the  pictures  under  his  scrutiny. — 
Montreal  Med.  Chroniclt. 


24  HENRY   C.   LEA'S  MEDICAL 

NEILL  (JOHN),   M.  D., 

Surgeon  to  thePennsylvania  Hospital, &c.;  and 

FRANCIS  GURNEY   SMITH,   M.D., 

Professor  of  Institutes  of  Medicine  in  the  Pennsylvania  Medical  College. 

AN  ANALYTICAL   COMPENDIUM    OF   THE    VARIOUS   BRANCHES 

OF  MEDICAL  SCIENCE  ;  for  the  Use  and  Examination  of  Students.  A  new  edition,  revised 
and  improved.  In  one  very  large  and  handsomely  printed  royal  12mo.  volume,  o(  about  one 
thousand  pages,  with  374  wood-cuts,  extra  cloth,  $4  00.  Strongly  bound  in  leather,  with  raised 
bands.     $4  Vf). 

This  work  is  again  presented  as  eminently  worthy  of  the  favor  with  which  it  has  hitherto 
been  received.  As  a  book  for  daily  reference  by  the  studeni  requiring  a  guide  to  his  more  elaborate 
text-books,  as  a  manual  for  preceptors  desiring  to  stimulate  their  students  by  frequent  and  accurate 
examination,  or  as  a  source  from  which  the  practitioners  of  older  date  may  easily  and  cheaply  acquire 
a  knowledge  of  the  changes  and  improvement  in  professional  science,  its  reputation  is  permanently 
established. 


The  best  work  of  the  kind  with  which  we  are 
acquainted. — Med.  Examiner . 

Having  made  free  use  of  this  volume  in  our  ex- 
aminations of  pupils,  we  can  speak  from  experi- 
ence in  recommending  it  as  an  admirable  compend 
for  students,  and  as  especially  useful  to  preceptors 
who  examine  their  pupils.  It  will  save  the  teacher 
much  labor  by  enabling  him  readily  to  recall  all  of 
the  points  upon  which  his  pupils  should  be  ex- 
amined. A  work  of  this  sort  should  be  in  the  hands 
of  every  one  who  takes  pupils  into  his  office  with  a 
vicwof  examining  them  ;  and  this  is  unquestionably 
the  beatof  its  class. — Transylvania  Med.  Journal, 


Td  the  rapid  course  of  lectures,  where  ■work  for 
the  students  is  heavy,  and  review  necessary  for  an 
exainin;ition,  a  compend  is  not  only  valuable,  but 
it  is  almost  a  /tine  qua  non.  The  one  before  us  is, 
in  most  of  the  divisions,  the  most  unexceptionable 
of  all  books  of  the  kind  that  we  know  of.  Tha 
newjEst  and  soundest  doctrines  and  the  latest  im- 
provements and  discoveries  are  explicitly,  though 
concisely,  laid  before  the  student.  There  is  a  class 
to  whom  ^ve  very  sincerely  commend  this  cheap  book 
as  worth  its  weight  in  silver — that  class  is  the  gradu- 
ates in  medicine  of  more  than  ten  years'  standing, 
who  have  not  studied  medicine  since. — Tht  St«iA*- 
scopt. 


PIRRIE  (WILLIAM),  F.  R.  S.  E., 

Professor  of  Surgery  in  the  University  of  Aberdeen. 

THE    PRINCIPLES  AND  PRACTICE  OF  SURGERY.    Edited  by  John 

Neill,  M.  D.,  Professor  of  Surgery  in  the  Penna.  Medical  College,  Surgeon  tothe  Pennsylvania 
Hospital,  &c.  In  one  very  handsome  Svo.  volume,  extra  cloth,  of  780  pages,  with  316  illustrations. 
$3  75. 

We  know  of  no  other  surgical  work  of  a  reason-  ;  rately  discussed  the  principles  of  surgery,  and  a 
able  size,  wherein  there  is  so  much  theory  and  prac-  ,  safe  and  effectual  practice  predicated  upon  them, 
tice,  or  where  subjects  are  more  soundly  or  clearly  !  Perhaps  no  work  upon  this  subject  heretofore  issued 
taught. — The  Stethoscope.  i  is  so  full  upon  the  science  of  the  art  of  surgery. — 

Prof.  Pirrie,  in  the  work  before  us,  has  elabo- |  NaskvilU  Journal  of  Medicine  and  Surgtry . 


PEREIRA  (JONATHAN),   M.D. 

EDITED  BY  PROF.  H.  C.  WOOD. 

MATERIA  MEDIC  A  AND  THERAPEUTICS;  being  an  Abridgment  of  the 

late  Dr.  Pereira's  Elements  of  Materia  Medica,  arranged  in  conformity  with  the  British  Pharma- 
copffiia,  and  adapted  to  the  use  of  Medical  Practitioners,  Chemi-ts,  and  Druggists,  Medical  and 
Pharmaceutical  Students,  &c.  By  F.  J.  Farre,  M.  D.,  Senior  Physician  to  St.  Bartholomew's 
Hospital,  and  London  Editor  of  the  British  Pharmacopoeia;  assisted  by  Robert  Bentley, 
M.R.  C.S.,  Professor  of  Materia  Medica  and  Botany  to  the  Ptiarmaceuiical  Society  of  Great 
Britain;  and  by  Robert  Warington,  F.  R.  S.,  Chemical  Operator  to  the  Society  of  Apothecaries. 
With  numerous  additions  and  references  to  the  United  Slates  Pharmacopoeia,  by  Horatio  C. 
Wood,  M.  D.,  Professor  of  Botany  in  the  University  of  Pennsylvania.  In  one  large  and  hand- 
some octavo  volume  of  about  yOO  pages,  with  numerous  illustrations.     (Preparing.) 


ROBERTS  (WILLIAM)  M.  D., 

Physician  to  the  Manchester  Royal  Infirmary,  Lecturer  on  Medicine  in  the  Manchester  School  of 

Medicine,  &c. 

A  PRACTICAL  TREATISE   ON   URINARY  AND  RENAL  DISEASES, 

including  Urinary  Deposits.  Illustrated  by  numerous  cases  and  engravings.  In  one  handsome 
octavo  volume  oi'  over  .000  pages,  extra  cloth.  Price  $4  &0.  (Now  Ready.) 
The  want  has  for  some  time  been  felt  of  a  work  which  should  render  accessible  to  the  American 
profession  in  a  com{>endious  and  convenient  form,  the  results  of  tiie  numerous  and  important  re- 
searches which  have  of  late  yeafs  elucidated  the  pathology  of  Urinary  and  Renal  Diseases.  It  has 
been  the  aim  of  the  author  in  the  present  volume  to  set  forth  in  a  form  divested  of  undue  techni- 
cality, the  practical  condition  of  the  subject  in  its  most  advanced  stage  of  progress.  In  endt-avor- 
ing  to  accomplish  this,  he  has  retrained  from  crowding  Ihu  volume  with  mmute  chemical  and  phv- 
piological  details,  which  would  unfit  it  for  its  object  of  ad'ording  to  the  physician  aguide  in  his  daily 
practice,  and  to  the  student  a  condensed  and  intelligible  compendium  of  all  that  is  practically  im- 
portant on  the  subject.  To  aid  in  this,  numerous  cases  and  illustrations  have  been  introduced 
throughout  the  work. 

The  book  is  beyond  question  the  most  comprchen-  1  possess  in  the  English  language. — British  Medical 
aive  work  on  irrinary  and    Ui-nal   DIseaEcs,  con-     Journal, 
Bidered  in  their  stricily  practical  aspect,  that  we  | 


AND   SCIENTIFIC    PUBLICATIONS 


25 


PARRISH   (EDWARD), 

ProfesHor  of  Matoria.  Jli'ilicii,  iu  tin;  I'liiliidolptii^  C')lloge  of  Pharmacy. 

A  TREATISE  o::i   PlIARMACV^.     Designed  as  a  Text-book  fur  tlio  Student, 

and  a^  u  (riiide  lor  Ihe  Phy>'ician  anc(.  PharinaceutiHt .     Wilh  many  Formula;  and  Pre-criplion». 

Third  edilioii,  greatly  itnpnjved.     In  one  handsdme  ortavo  volume,  of  850  pages,  with  several 

hundred  [llustralioii!*,  extra  cloth.     $0  00.     (Jusc  Issued.) 

Tluiiii^h  lor  some  time  out  of  print,  the  appearaii(;e  of  a  new  edition  of  this  work  has  been  de- 
layed lor  the  purpose  of  emfiodying  in  il  the  results  ol  ttie  new  U.  H.  Pharmacopceia.  The  pub- 
lication of  this  latter  has  enabled  the  author  to  complete  his  revi-ion  in  the  mo.st  thorough  manner. 
Those  who  have  been  waiting  for  the  work  may  therefore  rely  on  obtaining  a  volu'nne  completely 
on  a  level  with  the  most  advanced  condition  of  pharmaceutical  .science. 

The  favor  with  which  the  work  has  thus  far  been  received  shows  that  the  author  was  not  mis- 
taken in  his  estimate  of  the  want  of  a  treatise  which  should  serve  as  a  practical  text-book  for  all 
engaged  in  preparing  and  dispensing  medicines.  Such  a  guide  was  indispensable  not  only  to  the 
educated  pharmaceutist,  but  also  to  that  large  class  of  practitioners  throughout  the  country  who 
are  obliged  to  compound  their  own  prescriptions,  and  who  during  their  collegiate  course  have  no 
opportunity  of  obtaining  a  practical  familiarity  with  the  necessary  processes  and  manipulations. 
The  rapid  exhaustion  of  two  large  editions  is  evidence  that  the  author  has  succeeded  in  thoroughly 
carrying  out  his  object.  Since  the  appearance  of  the  last  edition,  much  has  been  done  to  perfect 
the  science  ;  the  new  Pharmacopteia  has  introduced  many  changes  to  which  the  profession  must 
conform;  and  the  author  has  labored  assiduously  to  embody  in  his  work  all  that  physicians  and 
pharmaceutists  can  ask  for  in  such  a  volume.  The  new  matter  alone  will  thus  be  found  worth 
more  than  the  very  moderate  co>t  of  the  work  to  those  who  have  been  using  the  previous  editions. 


All  that  we  can  Bay  of  it  is  that  to  the  practising 
pliysicitin,  and  especially  the  country  physician, 
wlio  is  generally  his  own  apothecary,  there  is  hard- 
ly any  book  that  might  not  better  be  dispensed  with 
It  is  at  the  same  time  a  dispensatory  and  a  pharma- 
cy.— Louisville  Review. 

A  careful  examination  of  this  work  enables  us  to 
speak  of  it  in  the  highest  terms,  as  being  the  best 
treatise  on  practical  pharmacy  with  which  we  are 
acquainted,  and  an  invaluable 'Uirfe-wecMm,  not  only 
to  the  apothecary  and  to  those  practitioners  who 
are  accustomed  to  prepare  tleir  own  medicines,  but 
to  every  medical  man  and  medical  student. — Boston 
Med.  and  Surg.  Journal. 

This  is  altogether  one  of  the  most  useful  books 
we  have  seen.  It  is  just  what  we  have  long  felt  to 
be  needed  by  apothecaries,  students,  and  practition- 
ers of  medicine,  must  of  whom  in  this  country  have 
ti)  put  up  their  own  prescriptions.  Il  bears,  upon 
every  page,  the  impress  of  prtictical  knowledge, 
conveyed  in  a  plain  common  sense  manner,  and 
adapted  to  the  comprehension  of  all  who  may  read 
it. — Southern  Med.  and  Surg.  Journal. 

That  Edward  Parrish,  in  writing  a  book  upon 
practical  Pharmacy  some  few  years  ago — one  emi- 
nently original  and  unique — did  the  medical  and 
pharmaceutical  professions  a  great:  and  valuable  ser- 
vice, no  one,  we  think,  who  has  had  access  to  its 
pages  will  denyj  doubly  welcome,  then,  is  this  new 


edition,  containing  the  added  results  of  his  recent 
and  rich  experience  as  an  observer,  teacher,  and 
practical  operator  in  the  pharmaceutical  laboratory. 
The  excellent  plan  of  the  first  is  more  thoroughly, 
— Peninsular  Med.  Journal,  Jan.  1860. 

Of  course,  all  apothecaries  who  have  not  already 
a  copy  of  the  first  edition  will  procure  one  of  this; 
it  is,  therefore,  to  physicians  residing  in  the  country 
and  in  small  towns,  who  cannot  avail  themselves  of 
the  skill  of  an  educated  pharmaceutist,  that  we 
would  especially  commend  this  work.  In  it  they 
will  find  all  that  they  desire  to  know,  and  should 
know,  but  very  little  of  which  they  do  really  icnow 
in  reference  to  this  important  collateral  branch  of 
their  profession;  for  it  is  a  well  establislied  fact, 
that,  in  the  education  of  physicians,  while  the  sci- 
ence of  medicine  is  generally  well  taught,  very 
little  attention  is  paid  to  the  art  of  preparing  them 
for  use,  and  we  know  not  how  this  defect  can  be  so 
well  remedied  as  by  procuring  and  consulting  Dr. 
Parrish's  excellent  work. — St.  Louis  Med.  Journal 
Jan. 1860. 

We  know  of  no  work  on  the  subject  which  would 
be  more  indispensable  to  the  physician  or  student 
desiring  information  on  the  subjectof  which  it  treats. 
With  Griffith's  "  Medical  Formulary"  and  this,  the 
practising  physician  would  be  supplied  with  nearly 
or  quite  all  the  most  useful  infor'nation  on  the  sub- 
ject.— C karleston  Med.  Jour. and  Review,  Jan.  1860. 


PEASLEE  (E.  R.),   M .  D., 

Professor  of  Physiology  and  General  Pathology  in  the  New  York  Medical  College. 

HUMAN  HlSTOLOG-Y,  in  its  relations  to  Anatomy,  Physiology,  and  Pathology; 

for  the  use  of  Medical  Students.    With  four  hundred  and.thirty-four  illustrations.    In  one  hand- 
some octavo  volume,  extra  cloth,  of  over  600  pages.     $3  75. 
It  embraces  a  library  upon  the  topics  discussed        We  would  recommend  it  as  containing  a  summary 


within  itself,  and  is  just  what  the  teacher  and  learner 
need.  Wc  have  not  only  the  whole  subject  of  His- 
tology, interesting  in  itself,  ably  and  fully  discussed, 
but  what  is  of  infinitely  greater  interest  to  the  stu- 
dent, because  of  greater  practical  value,  are  its  re- 
lations to  Anatomy,  Phj'siology,  and  Pathology, 
which  are  here  fully  and  satisfactorily  set  forth. — 
Nashville  Journ.  of  Med.  andSurgery. 


of  all  that  IS  known  of  the  important  subjects  which 
it  treats ;  of  all  that  is  in  the  great  works  of  Simon 
and  Lehmann,  and  the  organic  chemists  in  general. 
Master  this  one  volume,  and  you  know  all  that  is 
known  of  the  great  fundamental  principles  of  medi- 
cine, and  we  have  no  hesitation  in  sayin"  that  it 

is  an  honor  to  the  American  medical  profession. 

St.  Louis  Mid.  and  Surg.  Journal. 


ROKITANSKY 

Curator  of  the  Imperial  Pathological  Museum, 

A    MANUAL   OF  PATHOLOGICAL 

bound  in  two,  extra  cloth,  of  about  1200  pages 
KING,  C.  H.  MooRE,  and  G.  E.  Day.  $7  50. 
The  profession  is  too  well  acquainted  with  the  re- 
putation of  Rokitansky's  work  to  need  our  assur- 
ance that  this  is  one  of  the  mostprofound.  thorough, 
and  valuable  books  ever  issued  from  the  medical 
press.  It  is  «uig'sn«rt\"t,  and  has  no  standard  of  com- 
parison. It  is  only  necessary  to  announce  that  it  is 
issued  in  a  form  as  cheap  as  is  compatible  with  its 


(CARL),    M.  D., 

and  Professor  at  the  University  of  Vienna,  4;c 

ANATOMY.  Four  volumes,  octaro, 
Translated  by  W.  E.  Swaine,  Edward  SibvS- 

size  and  preservation,  and  its  sale  follows  as  a 
matter  of  course.  No  library  can  be  called  com 
plete  without  it.— £M^a/o  Med.  Journal. 

An  attempt  to  give  our  readers  any  adequate  idea 
of  the  vast  amount  of  instruction  accuinul.ucd  in 
these  volumes,  would  be  feeble  and  hopeless  — 
Western  Lancet. 


ROYLE'S   MATERIA   MEDICA   AND   THERAPEUTICS;   including  the 

Preparations  of  the  Pharmacopceias  of  London,  Edinburgh,  Dublin,  and  of  the  United  States 
Withmany  new  medicines.  Edited  by  Joseph  Carson,  JVI.  D.  Withainety-ei°-htilluslrationi* 
In  one  large  octavo  volume,  extra  cloth,  of  about  700  pages.    $3  00.  ° 


2G 


HENHY  C.   LEA'S  MEDICAL 


RIGBY    (EDWARD),    M.D., 

Senior  Physician  to  tlie  General  Lying-in  Hospital,  &c. 

A    SYSTEM    OF    MIDWIFERY.     With  Notes  and  Additional  Illustrations. 

Second  American  Edition.     One  volume  octavo,  extra  cloth,  422  pages.    $2  50. 

BY  THE  SAME  AUTHOR. 

ON  THE  CONSTITUTIONAL  TREATMENT  OF  FEMALE  DISEASES. 

In  one  neat  royal  12mo.  volume,  extra  cloth,  of  about  250  pages.    $1  00. 


RAMSBOTHAM  (FRANCIS  H.),   M.D. 
THE  PRINCIPLES  AND  PRACTICE  OF  OBSTETRIC  MEDICINE  AND 

SURGEK  Y,  in  reference  to  the  Process  of  Parturition.  A  new  and  enlarged  edition,  thoroughly 
revised  by  the  Author.  With  Addition:- by  W.V.  KEAfiNG.M.  D.,  Professor  of  Obstetrics,  &c.,  in 
the  Jeflerson  Medical  College,  Philadelphia.  In  one  large  and  handsome  imperial  octavo  volume, 
ol  650  pages,  strongly  bound  in  leather,  with  raised  bands;  with  sixty- four  beautiful  Plates,  and 
numerous  Wood-cuts  in  the  text,  containing  in  all  nearly  200  large  and  beautiful  figures.   $.7  00. 

From  Prof.  Hodge,  of  ikt  University  of  Pa. 
To  the  American  public,  it  is  most  valuable,  from  its  intrinsic  undoubted  excellence,  and  as  being 
the  best  authorized  exponent  of  British  Midwifery.   Its  circulation  will,  I  trust,  beextensive  throughout 
our  country. 


It  is  unnecessary  to  say  anything  in  regard  to  the 
utility  of  this  work.  It  is  already  appreciated  in  our 
country  for  the  value  of  the  matter,  the  cleariiess  of 
its  style,  and  the  fulness  of  its  illustrations.  To  the 
physician's  library  it  is  indispcnsaljle,  while  to  the 
student  as  a  text-bo<»k,  from  which  to  extract  the 
material  for  laying  the  foundation  of  an  education  on 
obstetrical  science,  it  has  no  superior. — Ohio  Med 
and  Surg.  Journal. 

The  publishers  have  secured  its  success  by  the 


truly  elegant  style  in  which  they  have  brought  it 
out,  excelling  themselves  in  its  production,  espe- 
cially in  its  plates.  It  is  dedicated  to  Prof.  Meigs, 
and  has  the  emphatic  endorsement  of  Prof.  Hodge, 
as  the  best  exponent  of  British  Midwifery.  We 
knc.w  of  no  text-book  which  deserves  in  all  respects 
to  be  more  highly  recommended  to  students,  and  we 
could  wish  to  see  it  in  the  handsof  every  practitioner, 
for  they  will  find  it  invaluable  for  reference. — Med. 
Gazette. 


RICORD  (P.),   M.  D. 
LETTERS  ON  SYPHILIS.     Translated  by  W.  P.  Lattimore,  M.D      In  one 

neat  octavo  volume,  of  270  pages,  extra  cloth.     $2  00. 


SMITH    (HENRY   H.),  M.  D.,  AND    HORN  ER  (W I  L  LI  AM  E.),  M.D. 
AN  ANATOMICAL  ATLAS,  illustrative  of  the  Structure  of  the  Human  Body. 

In  one  volume,  large  imperial  octavo,  extra  cloth,  with  about  six  hundred  and  fifty  beautiful 

figures.     $4  50. 

The  plan  of  this  Atlas,  which  renders  itsope-  I  of  the  kind  that  hasyet  appeared  ;  and  we  must  add. 
culiarly  convenient  for  the  student,  and  its  superb  ]  the  very  beautiful  manner  in  which  it  is  "  got  up'' 
artistical  execution, 'lave  hcen  already  pointed  out.  I  is  so  creditable  to  the  country  as  to  be  flattering 
We  must  congratulate  the  student  upon  the  comple-  to  our  nationsl  pride. — American  Medical  Journal. 
tion  of  this  Atlae,  as  it  is  the  most  convenient  work  \ 


SMITH  (EDWARD),   M.D.,  LL.D.,  F.R.S. 

Assistant  Physician  to  the  Hospital  for  Consumption  and  Diseases  of  the  Chest,  Brcmpton,  &c. 

CONSUMPTION;    ITS   EARLY  AND    REMEDIABLE    STAGES.     In  one 

neat  octavo  volume  of  2.54  pages,  extra  cloth.     $2  25. 

One-half  of  Dr.  Smith's  work  is  devoted  to  the  i  tlian  to  drugs  in  the  treatment  of  the  disease.  In 
treatment  of  Tuberculotis.  We  find  in  this  portion  taking  leave  of  tlie  work,  we  would  express  the 
of  the  work  no  occasion  to  join  issue  with  the  au-  hope  that  the  author  will  furnish  occasions  for  ihe 
thor  •  hut,  on  the  contrary,  much  which  we  would  renewal  of  our  intercourse  as  a  reader,  if  not  asa 
commend  to  the  reader's  attention.  Dr.  Smith  at-  leviewer. — Am.  Med.  Journal,  Jan.  1863. 
taches  far  greater  importance  to  hygienic  measures  ] 


SHARPEY  (WILLIAM),   M.D,,   JONES   QUAIN,    M.D.,   AND 

RICHARD   QUAIN,   F.  R.  S.,  <Stc. 

HUMAN  ANATOMY.     Revised,  with  Notes  and  Additions,  by  .Joseph  Letdt, 

M.  U.,  Professor  o(  Anatomy  in  the  University  of  Pennsylvania.     Complete  in  two  large  octavo 
volumes,  extra  cloth,  of  about  thirteen  hundred  pages.     With  over  500  illustrations     $6  00. 


SOI.LY  ON  THE  HUMAN  BRAIN  ;  itsStrueturc, 
Physiology,  and  Diseases.  From  the  Second  and 
much  enltiigeu  London  edition,  li/  one  ociav< 
volume,  exlra  cloth,  of  000  pages,  with  120  wood- 
cuts.   «2  .M». 

SKEY'S  OPERATIVE  SURGERY.     In  one  very 


handsome  octavo  volume,  extra  cloth,  of  over  650 
pages,  with  about  one  liundred  wood-cuts.  93  '25. 
SlMON>  UI;NKKA1.  PATHOLOGY,  as  conduc- 
ive to  the  Ksluhiislcmtnt  of  Kational  Priociplea 
for  the  prevention  anc  Cure  of  Disease  In  one 
octavo  volume,  extra  cloth,  of  212  pagea.    $1  25. 


STILLE  (ALFRED),    M.D., 

ProfosKor  of  tho  Tlionry  iirxl  I'nictico  of  Moilir;ine  In  tlie  Univf>r«ity  of  Pennsylvania. 

THERAPKUTK^y  AND  iMATElUA  MEDKJA;  a  Systematic  Treatise  on  tho 

Action  and  Use^'  of  Medicinal  Agents,  including  Ilit-ir  Description  and  History.  Second  Edition, 
revised  and  enlarged.  In  two  large  and  handsome  octavo  volumes,  extra  cloth.  $10  00. 
This  work  is  designed  especially  ("or  the  student  and  practitioner  of'medicine.  and  treats  the  various 
articles  oC  the  iVlateria  Medica  from  the  point  (jCview  ut'  the  hedside,  and  not  ot  the  shop  or  o(  tlie 
leciuie-rooni.  While  thus  endeavoring  to  give  all  practical  inCornialion  likely  to  be  useful  wiih 
respect  to  the  employment  of  special  remedies  in  special  all'ections,  and  the  results  to  be  anticipated 
from  their  administration,  a  copious  Index  of  Diseases  and  their  Remedies  renders  the  work  emi- 
nently titled  for  reference  by  showing  at  a  glance  the  different  means  which  have  been  employed, 
and  enabling  the  practitioner  to  extend  his  resources  in  diHicult  ca,-es  with  all  that  the  experience 
of  ilie  profession  has  suggested. 

The  speedy  demand  fur  another  edition  of  this  work  shows  that  it  has  acceptably  filled  an  acknow- 
ledged want  Noexertion  of  the  author  has  been  wanting  to  render  it  worthy  a  cuntiiiuance  of  the 
favor  with  which  it  has  been  received,  while  an  alieration  in  the  typographical  arraiioement  ha.i 
accomiuidated  the  additions  without  increasing  unduly  the  size  of  the  volumes. 

Rarely,  indeed,  have  we  had  submitted  ti)  us  a  i  tioncd,  Stille.  His  great  work  on  "  Materia  Medi- 
WDrk  on  medicine  so  ponderous  in  its  dimensions  |  ca  and  Tlierapeuties,"  puhlished  last  year,  in  two 
OS  that  now  before  us,  and  yet  so  fascinating  in  its  i  octavo  volumes,  of  some  si.\teen  liundred  pages 
C!)ntcni.s.  It  is,  tlierefore,  with  a  peculiar  giatili-  i  wliilc  it  embodies  the  results  of  the  labor  of  others 
cation  that  we  recognize  in  Dr.  Stille  tlie  posses-  j  up  to   the  time  of  pul)lication,  is  enriched  witli  a 

great  amount  of  original  observation  and  research. 
We  would  draw  attention,  by  the  way,  to  the  very 
convenient  mode  in  wliicli  tlie  I/i'le.z  is  arranged  in 
this  work.  There  is  firstan  "  Inde.v  of  Remedies;' 
next  an  "Index  of  Diseases  and  their  Remedies." 
Such  an  arrangement  of  tlie  Indices,  in  our  opinion, 
greatly  enhances  the  practical  value  of  books  of  this 
Ivind.  In  tedious,  obstinate  cases  of  disease,  where 
we  have  to  try  <me  remedy  after  another  until  our 
stock  is  pretty  nearly  exhausted,  and  we  are  almost 
driven  to  our  wit's  end,  such  an  index  as  the  second 
of  the  two  just  mentioned,  is  precisely  what  we 
want. — London  Med.  Times  and  Gazette,  April ,  1861. 
We  think  this  work  will  do  much  to  obviate  tlie 
reluctance  to  a  thorough  investigationof  tliis  branch 
of  scientific  study,  for  in  the  wide  range  of  meUical 
literature  treasured  in  the  Englisti  tongue,  we  shall 
hardly  find  a  work  written  in  a  style  more  clear  and 
simple.  Conveying  forcibly  the  facts  taught,  and  yet 
free  from  turgidity  and  redundancy.  There  is  a  fas- 
cination in  its  pages  that  will  insure  to  it  a  wide 
popularity  and  attentive  perusal,  and  a  degree  of 
usefulness  not  often  attained  through  the  influence 
of  a  single  work. 


sion  of  many  of  tiiose  more  distinguished  qualifica- 
tions which  entitle  him  to  approbation,  and  which 
Justify  him  in  coming  before  his  medical  brethren 
as  an  instructor.  A  comprehensive  knowledge, 
tcpted  by  a  sound  and  penetrating  judgment,  joined 
to  a  love  of  progress  — which  a  discriminating  spirit 
of  inquiry  has  tempered  so  as  to  accept  nothing  new 
because  it  is  new, and  abandon  nothing  old  because 
it  is  old,  but  which  estimates  either  accorcing  to  its 
rclaiitms  to  a  just  logic  and  experience — manifests 
itself  everywFiere,  and  gives  to  the  guidance  of  the 
author  all  'he  assurance  of  safety  which  the  diffi- 
culties of  his  subject  can  allow.  In  conclusion,  we 
earnestly  advise  our  readers  to  ascertain  for  thtm- 
Belves,  by  a  study  of  Dr  Stille's  volumes,  the  great 
value  and  interest  of  the  stores  of  knowledge  they 
present.  We  have  pleasure  in  referring  rather  to 
the  ample  treasury  of  undouljted  truths,  the  real  and 
assured  conquest  of  medicine,  accumulated  by  Dr. 
Stille  in  his  pages;  and  commend  the  sum  of  his  la- 
bors to  the  attention  of  our  readers,  as  alike  honor- 
able to  our  science,  and  creditable  to  the  zeal,  the 
candor,  and  the  judgment  of  him  who  has  garnered 
the  whole  so  carefully. —  Edinburgh  Med.  Journal. 
The  most  recent  authority  is  the  one  last  men- 


SIMPSON  (J.  Y.),   M.  D., 

Professor  of  Midwifery,  &c.,  in  the  University  of  Edinburgh, &c. 

CLINICAL  LECTURES   ON   THE  DISEASES   OF   WOMEN.     With  nu- 

meious  illustrations.     In  one  handsome  octavo  volume,  of  over  500  pages,  extra  cloth   $4  00. 

The  principal  topics  embraced  in  the  Lectures  are  Vesico-Vaginal  Fistula,  Cancer  of  the  Uterus 
Treatment  of  Carcinoma  by  Caustics,  Dysmenorrhoea,  Amenorrhoea,  Closures,  Contractions,  &c.' 
of  the  Vagina,  Vulvitis,  Causes  of  Death  after  Surgical  Operations,  Surgical  Fever,  Phle°-masia 
Dolens,  Coccyodinia,  Pelvic  Cellulitis,  Pelvic  Hsemato^ia,  Spurious  Pregnancy,  Ovarian  Dropsy, 
Ovariotomy,  Cranioclasm,  Diseases  of  the  Fallopian  Tubes,  Puerperal  Mania,  Sub-Involution  and 
Super-Involution  of  the  Uterus,  &c.  &c. 

As  a  series  of  monographs  on  these  important  topics — many  of  which  receive  little  attention 
in  the  ordinary  text-books — elucidated  with  the  extensive  experience  and  readiness  of  resource  for 
which  Prolessor  Simpson  is  so  distinguished,  there  are  few  practitioners  who  will  not  find  in  its 
pages  matter  of  the  utmost  importance  in  the  Ireatmant  of  obscure  and  dilficult  cases. 

SALTER  (H.    HJ,    M .  D. 
ASTHMA;  its  Pathology,  Causes,  Consequences,  and  Treatment.     In  one  vol. 

Svo.,  extra  cloth.     $2  50. 


The  portion  of  Dr.  Salter's  work  which  is  devoted 
to  treatment,  is  of  great  practical  interest  and  value. 
It  would  be  necessary  to  loilow  him  step  by  step 
in  his  remarks,  not  only  on  tlie  medicinal,  but  also 
on  the  dietetic  and  hygienic  treatment  of  the  disease, 
in  order  to  convey  a  just  notion  of  tne  practical  value 
of  this  part  of  his  work.    This  our  space  forbuis. 


and  this  we  shall  little  regret,  if,  by  our  silence, 
We  should  induce  our  readers  to  possess  ihenioelvea 
of  the  book  itself;  a  book  which,  without  uoubt,  de- 
serves to  be  ranked  ammg  tlie  most  valuable  of  re- 
cent contributions  to  the  medical  literature  of  this 
country.— jKanting-'s  Abstract,  Jan.,  ISOl. 


SLADE   ^O.   D.),    M,   D. 
DIPHTHERIA:   its  Nature  and  Treatment,  with  an  account  of  the  History  of 

its  Prevalence  in  various  countries.     Second  and  revised  edition.     In  one  neat  royal  12mo. 
volume,  extra  cloth.     $1  25.      {Just  Issued.) 


Tlie  original  essay  of  Dr.  Slade,  to  which  the 
Fiske  FunU  prize  (or  166(1  was  awarded,  appeared 
originally  in  this  .lournnl.  In  the  edition  belore  us 
the  essay  has  been  revised  with  evioent  care,  waile 
such  additions  have  been  maJe  to  it  us  were  sug 
gested  by  the  author's  subsequent  experience  and 


observation.  In  its  present  form,  the  work  furnishfs 
to  the  student  and  young  praclilioner  a  very  faithful 
and  usel'ul  exposition  of  tlu  principal  facts  that  are 
now  known  in  respect  to  <he  nature  of  diphtliena, 
itscauseg  and  treatment. — Am  Journ.  Med.  Stiencei, 
Jau.  Ib6.5. 


28 


HENRY   C.    LEA'S  MEDICAL 


SARGENT  (F.  W.),   M.  D. 
ON  BANDAGING  AND  OTHER  OPERATIONS  OF  MINOR  SURGERY. 

New  edition,  wiih  an  additional  chapter  on  Military  Surgery.     One  handsome  royal  12mo.  vol,, 

of'nearly  400  pages,  with  184  wood  cuts.     Extra  cloth,  $1  7.5. 

The  value  of  this  work  as  a  handy  and  convenient  manual  for  surgeons  engaged  in  active  duly,  has 
induced  the  publishers  to  render  it  more  complete  for  those  purposes  by  the  addition  of  a  chapter 
on  gun-shot  wounds  and  other  matters  peculiar  to  military  surgery.  In  its  present  form,  there- 
lore,  it  will  be  found  a  very  cheap  and  convenient  vade-mecum  for  consultation  and  relerence  in 
the  daily  exigencies  of  military  as  well  as  civil  practice. 


We  consider  that  no  better  book  could  be  placed 
in  the  hands  of  an  hospital  dresser,  or  the  young  sur- 
geon, whose  education  in  this  respect  has  not  been 
perfected.  We  most  cordially  commend  this  volume 
as  one  which  the  medical  student  should  most  close- 
ly study,  to  perfect  himsf  If  in  these  minor  surgical 
operations  in  which  neatness  and  dexterity  are  so 
much  required,  and  on  which  a  great  portion  of  his 
rtputation  as  a  future  surgeon  must  evidently  rest. 
And  to  the  surgeon  in  practice  it  must  prove  itself 
a  valuable  volume,  as  instructive  on  many  points 
which  he  may  have  forgotten. — British  American 
Jo«r«aZ,  May,  1862. 


The  instruction  given  upon  the  subject  of  JBn«- 
daging,  is  alone  of  great  value,  and  while  the  author 
modestly  proposes  to  instruct  the  students  of  medi- 
cine, and  the  younger  physicians,  we  will  say  that 
experienced  physicians  will  obtain  many  exceed- 
ingly valuable  suggestions  by  its  perusal.  It  will 
be  found  one  of  the  most  satisfactory  manuals  for  re- 
ference in  the  field,  or  hospital  yet  published;  thor- 
oughly adapted  to  the  wants  of  Military  surgeons^ 
and  at  the  same  time  equally  useful  for  ready  and 
convenient  reference  by  surgeons  everywhere. — 
Buffalo  Med.  and  Surg.  Journal,  June,  1862. 


OF 


SMITH   (W.   TYLER),  M.  D., 

Physician  Accoucheur  to  St.  Mary's  Hospital,  &c . 

ON   PARTURITION,   AND   THE    PRINCIPLES   AND   PRACTICE 

OBSTETRICS.    In  one  royal  12mo.  volume,  extra  cloth,  of  400  pages.     $1  50. 

BY  THE  SAME  AUTHOR. 

A  PRACTICAL  TREATISE  ON  THE  PATHOLOGY  AND  TREATMENT 

OF  LEUCORRHCEA.    With  numerous  illustrations.    In  one  very  handsome  octavo  volume, 
extra  cloth,  of  about  250  pages.    $2  00 

TANNER   (T.    H.),    M.  D., 

Physician  to  the  Hospital  for  Women,  &'c, 

A  MANUAL  OF  CLINICAL  MEDICINE  AND  PHYSICAL  DIAGNOSIS. 

To   which   is  added   The  Code   of  Ethics   of  the  American    Medical  Association.     Third 
American  Edition.     In  one  neat  volume,  small  12mo.,  extra  cloth.     (Preparirg.) 


TAYLOR  (ALFRED  S.),  M .  D.,  F.  R.  S., 

Lecturer  on  MedicalJurisprudence  and  Chemistry  in  Guy's  Hospital. 

MEDICAL  JURISPRUDENCE.     Fifth  American,  from  the  seventh  improved 

and  enlarged  London  edition.  With  Notes  and  References  to  American  Decisions,  by  Edward 
Hartshorne,M.  D.  InonelargeSvo.  volume,  extra  cloth,  of  over700  pages.  $4  00. 
This  standard  work  having  had  the  advantage  of  two  revisions  at  the  hands  of  the  author  since 
the  appearance  of  the  last  American  edition,  will  be  found  ihoioughly  revised  and  brought  up  com- 
pletely to  the  present  state  of  the  science.  As  a  work  of  authority,  it  must  therefore  maintain  its 
position,  both  as  a  text-book  for  the  student,  and  a  compendious  treatise  to  which  the  practitioner 
can  at  all  times  refer  in  cases  of  doubt  or  difficulty. 

American  and  British  legal  medicine.  It  should  be 
in  the  possession  of  every  physician,  as  the  subject 
is  ore  of  great  and  increasing  importance  to  the 
public  as  well  as  to  the  profession. — St.  Louis  Mtd. 


No  work  upon  the  subject  can  be  put  into  the 
hands  of  students  either  of  law  or  medicine  which 
will  engage  them  more  closely  or  profitably  ;  and 
none  could  be  offered  to  the  busy  practitioner  of 
either  calling,  for  the  purpose  of  casual  <lr  hasty 
reference,  thatwould  be  more  likely  toafford  the  aid 
desired.  We  thereforerecommend  it  as  the  best  and 
safest  manual  for  daily  \XiG.— American  Journal  oj 
Medical  Sciences. 

It  is  not  excess  of  praise  to  say  that  the  volumt 
before  us  is  the  very  best  treatise  extant  on  Medical 
Jurisprudence,  in  saying  this,  we  do  not  wish  to 
be  understood  as  detracting  from  the  merits  of  the 
excellent  v/orks  of  Beck,  Ryan,  Traill,  Guy,  and 
others;  but  in  interest  and  value  we  think  it  must 
be  concetled  that  Taylor  is  superior  to  anything  that 
has  preceded  it.— iV.  W.  Medical  and  Surg.  Journal 

It  is  at  once  comprehensive  and  eminently  prac- 
tical, and  by  universal  consent  stands  at  the  head  of 


and  Surg.  Journal. 

This  work  of  Dr.  Taylor's  is  generally  acknow- 
ledged to  be  one  of  the  ablest  extant  on  the  subject 
of  medical  jurisprudence.  It  is  certainly  one  of  the 
most  attractive  uouks  that  we  have  met  with  ;  sup- 
plying so  much  both  to  interest  and  instruct,  that 
we  do  not  hesitate  to  affirm  that  after  having  once 
Cdiiiinenced  its  perusal,  few  could  he  prevailed  upon 
to  desist  before  completing  it.  In  the  last  Lonilon 
editiim,  all  the  newly  observed  and  accurately  re- 
corded facts  have  been  inserted,  including  much 
that  is  recent  of  Chemical,  Microscopical,  and  Pa- 
thological research,  besidts  papers  on  numerous 
subjects  never  b<;fore  published. — Charleston  Med. 
Journal  and  Review. 

BY    THE  SAME  AUTHOR. 

ON  POISONS,  IN  RELATIOJN  TO  MEDICAL  JURISPRUDENCE  AND 

MEDICINE.    Second  American,  from  a  second  and  revised  London  edition.     In  one  large 

octavo  volume,  of  755  pages,  extra  cloth.     $5  00. 

Mr.  Taylor's  position  as  the  leading  medical  jurist  of  England,  has  conferred  on  him  extraordi- 
nary advantages  in  acquiring  experience  on  these  subjects,  nearly  all  cases  of  moment  being 
referred  to  him  for  examination,  as  an  expert  whose  testimony  is  generally  accepted  as  final. 
The  results  of  his  labors,  therefore,  us  gathered  together  in  thi^  volume,  ciireliilly  weighed  and 
silled,  and  presented  in  the  clear  and  intelligible  style  for  which  he  is  noted,  may  be  received 
88  an  acknowledged  authority,  and  a>  a  guide  to  be  followed  with  implicit  confidence. 

BY  THE  SAIMK  AUTHOR  AND  WM.  BRANDE. 

CHEMISTRY.     In  cue  volume  »vo.     See  "Brande,"  p.  6. 


AND    SCIENTIFIC   PUBLICATIONS,  29 

TODD  (ROBERT  BENTLEY),  M.  D.,  F.  R.  S., 

Profffsor  i>f  Phy8iiil<igy  in  King'n  College,  London;  and 

WILLIAM  BOWMANT,  F.  R.  S., 
Demonstrator  of  Anatomy  in  King's  College,  London. 

THE  PHYSIOLOGICAL  ANATOMY  AND  PHYSIOLOGY  OF  MAN.    With 

about  three  hundredlarge  and  beautiful  illustrations  on  wood.     Complete  in  one  large  octavo 

volume,  of  950  pages,  extra  clotli.     Price  S4  75. 

Itis  mi)reconeiBethanCarpenter'8PrincipleB,and  i  A  magnificent  contribution  to  Britiah  medicine, 
more  modern  than  the  accessible  edition  of  Mailer's  {  and  the  American  physician  who  shall  fail  to  peruse 
Elements;  its  details  are  brief,  bat  sufficieLt;  its  j  it,  wih  have  failed  to  read  one  of  the  most  instruc- 
descriplions  vivid;  its  illustrations  exact  and  copi-  tive  books  of  the  nineteenth  century. — iV.  O.  Mtd. 
ous  ;  and  its  language  terse  and  perspicuous. —  land  Siirg.  Journal. 
Charleston  Med.  Journal.  I 


TODD  (R.   B.)     M.  D.,    F.  R.  S.,  8e.c. 
CLINICAL  LECTURES  ON  CERTAIN   DISEASES  OF  THE  URINARY 

ORGANS  AND  ON  DROPSIES.    In  one  octavo  volume,  284' pages,  extra  cloth.     $2  50. 

BY  THE  SAME  AUTHOE. 

CLINICAL  LECTURES  ON  CERTAIN  ACUTE  DISEASES.     In  one  neat 

octavo  volume,  of  320  pages,  extra  clotn.     52  -50. 


TOYNBEE  (JOSEPH),   F.  R.  S., 
Anral  Surgeon  to,  and  Lecturer  on  Surgeri"  at,  St.  Mary's  Hospital. 

A  PRACTICAL  TREATISE  ON  DISEASES   OF   THE   EAR;   their  Diag- 

nosis,  Patholo^',  and  Treatment.     Illustrated  with  one  hundred  engravings  on  wood.    In  one 

very  handsome  octavo  volume,  extra  cloth,  S4  f'O. 

The  work  is  a  model  of  its  kind,  and  every  page  Surgery,  it  is  without  a  rival  in  our  language  or  any 
and  paragraph  of  it  are  worthy  of  the  mfist  thorough  other.— Charleston  Med.  Journ.  ararfiJeiv,  Sept  I860 
study.  Considered  all  in  all-as  an  original  work,  j  Ttie  work  of  Mr.  Toynbee  is  undoubtedly,  upon 
well  written,  philosophically  elaborated,  and  happi-  t^e  whole,  the  most  valuable  production  of  tne  kind 
y  illustrated  with  cases  and  drawings-it  is  by  far    ;„  language.     The  author  has  long  been  known 


We  are  speaking  within  the  limits  of  modest  ac-  guide  for  the  study  of  the  diseases  of  the  tar  in  any 
knowledgment,  and  with  a  sincere  and  untiiassed  language,  and  should  be  in  the  library  vf  every  phy- 
jttdgmenl,  when  we  affirm  that  as  a  treatise  on  Aural    sician.— C/iicago  Med.  Journal,  July,  1860. 

WILLIAMS  (C.   J.   B.),    M.D.,    F.  R.  S., 

Professor  of  Clinical  Medicine  in  University  College,  London,  ftc. 

PRINCIPLES  OF  MEDICINE.     An  Elementaiy  View  of  the  Causes,  Nature, 

Treatment,  Diagnosis,  and  Prognosis  of  Disease;  with  brief  remarks  on  Hj'gienics,  or  the  pre- 
servation ofhealth.  A  new  American, t>om  the  ihirdandrevisedLondonedition.  Inoneoctavo 
volume,  extra  cloth,  ol  about  500  pages.      S3  50. 

WHAT  TO  OBSERVE 
AT  THE  BEDSIDE  AND  AFTER  DEATH,  IN  MEDICAL  CASES. 

Publishedundertheauthority  ofthe  London  Society  tor  Medical  Observation.     A  new  American 

from  the  second  and  revised  Londoi.  edition.    In  one  very  handsome  volume,  royal  12mo.,  extra 

cloth.    $1  GO. 

To  the  observer  who  prefers  accuracy  to  blunders  I  One  of  the  finest  aids  to  a  young  practitioner 'wa 
and  precision  to  carelessness,  this  little  book  is  in-  have  everseen. — Ptninstilar  Journal  of  Mtdicin*. 
valuable. — N.  H.  Journal  of  Mtdicint .  I 


WALSHE  (W,    H.),   M.  D., 

Professor  of  the  Principles  and  Practice  of  Medicine  in  University  College,  London.  &c. 

A  PRACTICAL  TREATISE  ON  DISEASES  OF  THE  LUNGS;  including 

the  Principles  of  Physical  Diagnosis.  Third  American,  from  the  third  revised  and  much  en- 
larged Lonc'on  edition.  In  one  vol.  octavo,  of  468  pages  extra  cloth  $3  00. 
The  present  edition  has  been  carefully  revised  and  much  enlarged,  and  may  be  said  in  the  main 
to  be  rewritten.  Descriptions  of  several  diseases,  previou-ly  omitted,  are  now  introduced;  an 
effort  has  been  made  to  bring  the  description  of  anatomical  characters  to  the  level  of  the  wants  of 
the  practical  physician  ;  and  the  diagnosis  and  prognosis  of  each  complaint  are  more  completely 
considered.  The  sections  on  Treatment  and  the  Appendix  have,  e?pecially,  been  largely  ex- 
tended.— AutJior^s  Preface. 

BY  THE  SAME  AUTHOR. 

A  PRACTICAL  TREATISE  ON  THE  DISEASES  OF  THE  HEART  AND 

GREAT  VESSELS,  including  the  Principles  of  Physical  Diagnosis.  Third  American,  from  the 
third  revised  and  much  enlarged  London  edition.  In  one  handsome  octavo  volume  of  420  pages, 
extra  cloth.     $3  00. 

The  present  edition  has  Ijeen  carefully  revised  ;  much  new  matter  has  been  added,  and  the  entire 
work  in  a  measure  remodelled.  Numerous  facts  and  discussions,  more  or  less  completely  novel, 
■will  be  found  in  the  de-criplion  of  the  principles  of  physical  diagnosis;  but  the  chief  additions  have 
been  made  in  the  practical  portions  of  the  book.  Several  ati'ections,  of  which  little  or  no  account 
had  been  given  in  the  previous  editions,  are  now  treated  of  in  detail.— .4/rfA«r'«  Preface. 


HENRY  C.   LEA'S   MEDICAL 


Ne-w  and  much  enlarged  edition. 

WATSON    (THOMAS),    M.  D.,    Sec, 

Late  Physician  to  the  Middlesex  Hospital,  &e. 

LECTURES    ON    THE    PRINCIPLES    AND    PRACTICE   OF   PHYSIC. 

Delivered  at  King's  Colleg-e,  London.     A  new  American,  from  the  la.st  revised  and  enlarged 

English  edition,  with  Additions,  by  D.  Francis  Condie,  M.  D.,  author  of  "A  Practical  Treatise 

on  the  Diseases  oi'Children,"  &c.     With  one  hundred  and  eighty. five  illustrations  on  wood.     In 

one  very  large  and  handsome  volume,  imperial  octavo,  of  over  1200  closely  printed  pages  in 

small  type;  extra  cloth,  $6  50;  strongly  bound  in  leather,  with  raised  bands,  $7  &0. 

That  the  high  reputation  of  this  work  might  be  fully  maintained,  the  author  has  subjected  it  to  a 

thorough  revision;  every  portion  has  been  examined  with  the  aid  of  the  most  recent  researches 

in  pathology,  and  the  results  of  modern  investigations  in  both  theoretical  and  practical  subjects 

have  been  carefully  weighed  and  embodied  throughout  its  pages.     The  watchful  scrutiny  of  the 

editor  has  likewise  introduced  whatever  possesses  immediate  importance  to  the  American  physician 

in  relation  to  diseases  incident  to  our  climate  which  are  little  known  in  England,  as  well  as  those 

points  in  which  experience  here  has  led  to  different  modes  of  practice ;  and  he  has  also  added  largely 

to  the  series  of  illustrations,  believing  that  in  this  manner  valuable  assistance  may  be  conveyed  to 

the  student  in  elucidating  the  text.     The  work  will,  therefore,  be  found  thoroughly  on  a  level  with 

the  most  advanced  state  of  medical  science  on  both  sides  of  the  Atlantic. 

The  additions  which  the  work  has  received  are  shown  by  the  tact  that  notwithstanding  an  en- 
largement in  the  size  of  the  page,  more  than  two  hundred  additional  pages  have  been  necessary 
to  accommodate  the  two  large  volumes  ol'  the  London  edition  (which  sells  at  tea  dollars),  within 
the  compass  of  a  single  volume,' and  in  its  present  form  it  contains  the  matter  of  at  least  three 
ordinary  octavos.  Believing  it  to  be  a  work  which  should  lie  on  the  table  of  every  physician,  and 
be  in  the  hands  of  every  student,  the  publishers  have  put  it  at  a  price  within  the  reach  ol  all,  making 
it  one  of  the  cheapest  books  as  yet  pr-^sented  to  the  American  profession,  while  at  the  same  time 
the  beauty  ol  its  mechanical  executioii  renders  it  an  exceedingly  attractive  volume. 


The  fourth  edition  now  appears,  so  carefully  re- 
vised, as  to  add  considerably  to  the  value  of  a  book 
already  acknowledged,  wherever  the  English  lan- 
guage is  read,  to  be  beyond  ail  comparison  the  best 
sysfematic  work  on  the  Principles  and  Practice  of 
Physic  in  the  whole  range  of  medical  literature. 
Every  lecture  contains  proof  of  the  extreme  anxiety 
of  the  author  to  keep  pace  with  ihe  advancing  know- 
ledge of  the  day  One  scarcely  knows  whether 
to  admire  most  the  pure,  simple,  forcible  English — 
the  vast  amount  of  useful  practical  information 
condensed  into  the  Lectures — or  the  manly,  kind- 
hearted,  unassuming  character  of  the  lecturer  shin- 
ing through  his  work.— Lowd.  Med.  Times. 

Thus  these  admirable  volumes  come  before  the 
profession  in  their  fourtli  editicm, abounding  in  those 
distinguished  attributes  of  modenition,  judgment, 
erudite  cultivation,  clearness,  and  eloquence,  with 
which  they  were  from  the  first  invested,  but  yet 
richer  than  before  in  the  results  of  more  prolonged 
observati(m,  and  in  the  able  appreciation  of  the 
latest  advances  in  pathology  and  medicine  by  one 
of  the  most  profound  medical  thinkers  of  the  day. — 
London  Lancet. 


The  lecturer's  skill,  his  wisdom,  his  learning,  are 
equalled  by  the  ease  of  his  graceful  diction,  his  eln- 
quence,  and  the  far  higher  qualities  of  candor,  of 
courtesyj  of  modesty,  and  of  generous  appreciation 
of  merit  in  others. — N.  A.  Med  -Chir   Review. 

Watson's  unrivalled,  perhaps  unapproachable 
work  on  Practice — the  copious  additions  made  to 
which  (the  fourth  edition)  have  given  it  all  the  no- 
velty and  much  of  the  interest  of  a  new  book. — 
Charleston  Med.  Journal. 

Lecturers,  practitioners,  and  students  of  medicine 
will  equally  hail  the  reappearance  of  the  work  of 
Dr.  Watson  in  the  form  of  a  new — a  fourth — edition. 
We  merely  do  justice  to  our  own  feelings,  and,  we 
are  sure,  of  the  whole  profession,  if  we  tlianlc  him 
for  having,  in  the  trouble  and  turmoil  of  a  large 
practice,  made  leisure  to  supply  the  hiatus  caused 
by  the  exhaustion  of  the  tliird  edition.  For  Dr. 
\Vatson  has  not  merely  caused  the  lectures  to  be 
reprinted,  but  scattered  through  the  whole  work  we 
find  additions  or  alterations  which  prove  that  the 
author  has  in  every  way  sought  to  bring  up  his  teach- 
ing to  the  level  of  the  most  recent  acquisitions  in 
science. — Brit,  and  For.  Medico-Ckir. Review. 


New  and  much  enlarged  edition. 

WILSON    (ERASMUS),   F.  R.  S. 

A  SYSTEM  OF  HUMAN  ANATOMY,  General  and  Special.     A  new  and  re- 

vised  American,  from  the  last  and  enlarged  Engli.-h  Edition.  Edited  by  W.  H.Gobrecht,  M.  D., 
Professor  of  Anatomy  in  the  Pennsylvania  Medical  College,  &c.  llluslraled  with  three  hundred 
and  ninety-seven  engravings  on  wood.  In  one  large  and  handsome  octavo  volume,  ol  over  600 
large  pages;  extra  cloth,  $4  00. 

The  publishers  trust  that  the  well  earned  reputation  so  long  enjoyed  by  this  work  will  be  more 
than  maintained  by  the  present  edition.  Besides  a  very  thorough  revision  by  the  author,  it  has  been 
most  carefully  examined  by  the  etlilor,  and  (lie  efforts  of  both  have  been  directed  to  introducing 
everything  which  increa>ed  experit  nee  in  its  u>e  has  suggested  as  desirable  to  render  it  a  complete 
text-book  for  those  seeking  to  obtain  or  to  renew  an  aci|uainlance  with  Human  Anatomy.  The 
amount  of  additions  which  it  has  thus  received  may  be  estimated  from  the  lad  tliat  the  pre.-ent 
edition  contains  over  one-fourth  more  matter  than  the  last,  rendering  a  smaller  type  and  an  enlarged 
page  requisite  to  keep  the  volume  within  a  convenient  size.  The  editor  has  exercised  the  utmost 
caution  to  obtain  entire  accuracy  in  the  text,  and  has  largely  increa.sed  the  number  of  illustra- 
tions, of  which  there  are  about  one  hundred  and  fitly  more  in  this  edition  than  in  the  last,  thus 
bringing  distinctly  before  the  eye  of  the  student  everything  of  interest  or  importance. 

It  may  be  recommended  to  the  student  as  no  less    beauty  of  its  meclianical  execution,  and  the  clear- 
distinguished  by  its  accuracy  and  clearness  of  de- 
•cription  than  by  its  typographical  elegauce.     The 
wood-cuts  are  exquisite. — Brit,  and  For.  Medical 
Review. 


An  elegant  edition  of  one  of  the  most  useful  and 
accurate  systems  of  anatomical  science  which  has 
been  issued  from  the  press  Tlie  illustrations  are 
really  beautiful .  In  its  style  the  work  is  extremely 
concise  anil  inlelliRible.  No  one  can  possibly  lake 
up  this  volume  without  being  struck  with  the  great 


ncKS  of  the  descriptions  which  it  contains  is  equally 
evident.  Let  students,  by  all  means  examine  tiie 
claims  of  this  work  on  their  notice,  before  ctiey  pur- 
chase a  text-book  of  the  vitally  important  science 
which  this  volume  so  fully  and  easily  unfolds. — 
Lancet. 

We  regard  it  as  the  best  system  now  extant  for 
students. —  Western  Lancet. 

It  therefore  receives  our  highestcommendation.^ 
Southern  Med.  and  Surg.  Journal. 


AND   SCIENTIFIC   PUBLICATIONS. 


31 


WILSON    (ERASMUS),    T.   R.  S. 

ON  DISEASES  OF  THE  SKIN.  Fifth  American,  from  the  Fifth  enlarged 
London  edition.  In  one  handsome  octavo  volume,  of  nearly  700  large  pages,  wilh  illustralions 
on  wood,  exlia  cloth      $4  &0. 

This  dassiral  worl:,  which  for  twenly  years  has  occupied  the  position  of  the  leading  authority 
in  the  English  language  on  its  important  subject,  has  just  received  a  thorough  revision  at  the  hands 
of  the  Hulhiir,  and  is  now  presented  as  embodying  the  results  of  the  latest  investigations  and  i-xj.e- 
rien<;e  on  all  mutters  connected  with  diseases  of  the  skin.  The  increase  in  the  size  of  the  work 
shows  ih(!  industry  of  the  author,  and  his  deiermination  that  it  stiall  maintain  the  position  which  it 
has  acquired  as  thoroughly  on  a  level  wilh  the  most  advaaced  conditioa  of  medical  science. 

A  few  notices  of  the  last  edition  are  appended. 


The  writings  of  Wilson,  upondiscasesof  the  skin, 
are  by  fur  the  most  scientific  iinil  practical  lliat 
have  ever  l)een  presented  to  the  uiedicai  world  on 
this  subject.  Tlie  prcsentedition  isa  great  improve- 
ment (in  all  its  predecessors.  To  dwell  upon  all  the 
great  merits  and  liigli  claims  of  the  work  before  us. 
icrinfim,  would  indi'ed  be  an  agreeable  service  ;  it 
would  l)e  a  mental  homage  wliicli  we  eoukl  freely 
otTer,  but  we  should  liius  occupy  an  undue  aninunl 
of  space  in  tliis  Jowrna/.  We  will,  howtver  look 
at  some  of  the  more  salient  points  wilh  whieli  il 
abounds, and  which  make  iiinconipuiuoiysuperior  lo 
all  other  treatises  on  the  subjectol" dermatology  No 
mere  speculative  views  are  allowed  a  place  in  this 
volume,  which,  without  a  doubt  will,  for  a  very  long 
period,  be  acknowledged  as  the  chief  standard  work 
on  dermatology.  The  principles  of  an  enlightened 
and  rational  therapeia  are  introduced  on  every  ap- 
propriate occasion. — Am.  Jour.  Med  Science. 

When  the  first  edition  of  this  work  appeared 
about  t'ourleen  years  ago,  Mr  Erasmus  \\  ilson  haa 
already  given  some  years  to  the  study  of  Diseases 
of  the  Skin,  and  he  then  expressed  his  intention  of 
devoting  his  future  life  to  the  elucidation  of  this 
branch  of  Medical  Science  In  the  present  edition 
Mr.  Wilson  presents  us  with  the  results  of  his  ma- 
tured experience,  and  we  have  now  before  us  not 
merely  a  reprint  of  his  former  publieations,  but  an 
entirely  new  and  rewritten  volume.  Thus,  the  whole 
history  ot  the  diseases  affecting  the  skin,  whether 
they  originate  in  that  structure  or  are  the  mere  mani- 
festations of  derangement  of  internal  organs,  is 
brought  under  notice,  and  the  book  includes  a  mass 
of  information  which  is  spread  over  a  gieat  part  of 
the  domain  of  Medical  and  Surgical  Patliology .  We 
can  safely  recommend  it  to  the  proiession  as  the 
best  work  on  the  subject  now  in  existence  in  the  En- 
glish language. — London  Med.  Times  and  Gazette. 


No  matter  what  other  treatises  may  be  in  the  libra- 
ry of  the  medical  attendant,  he  needs  the  clear  nod 
Kugge.slive  counsels  of  Wilson,  who  is  thoroughly 
posted  up  on  all  subjects  connected  with  cutaneous 
pathology.  We  have,  it  is  very  true,  other  valuable 
works  on  the  maladies  that  iuvade  the  skin;  but, 
compared  with  the  volume  under  consideration,  they 
are  certainly  to  be  regarded  as  inferior  lights  in  guid- 
ing the  judgment  of  the  medical  man. — Boston  Med. 
and  Surg.  Journal,  Oct.  18.07. 

The  author  adopts  a  simple  and  entertaining  style. 
He  strives  to  clear  away  the  complications  of  his 
subject,  and  has  thus  produced  a  book  tilled  with  a 
vast  amount  of  information,  in  a  form  so  agreeable 
as  to  make  it  pleasant  reading,  even  to  the  uninitiated. 
More  especially  does  it  deserve  our  praise  because  of 
its  beautiful  and  complete  atlas,  which  the  Aniericaa 
publishers  have  successfully  imitated  from  the  origi- 
nal plates.  We  pronounce  them  by  far  the  best  imi- 
tations of  nature  yet  published  in  our  country.  With 
the  text-book  and  atlas  at  hand,  the  diagnosis  is  ren- 
dered easy  and  accurate,  and  the  practitioner  feels 
himself  safe  in  his  treatment.  We  will  add  that  this 
work,  although  it  must  have  been  very  expensive  to 
the  pultlishers,  is  not  high  priced.  There  is  no  rea- 
son, then,  to  prevent  every  physician  from  obtaining 
a  work  of  such  importance,  and  one  which  will  save 
him  both  labor  and  perplexity. —  Va.  Med.  Joui-nal. 

As  a  practical  guide  to  the  classification,  dingnosis 
and  treatment  of  the  diseases  of  the  skin,  the  book  is 
complete.  We  know  nothing,  considered  in  this  as- 
pect, better  in  our  language;  it  is  a  safe  authority  on 
all  the  ordinary  matters  which,  in  this  range  of  dis- 
eases, engage  the  practitioner's  attention,  and  pos- 
sesses the  high  quality  —  unknown,  we  believe,  to 
every  older  manual,  of  being  on  a  level  with  science's 
high-water  mark  ;  a  sound  book  of  practice. — Lundun 
Med.  Times. 


ALSO, 

A  SERIES  OF  PLATES  ILLUSTRATING  WILSON  ON  DISEASES  OF 

THE  SKIN  ;  consisting  of  twenty  beautifully  executed  plates,  of  which  thirteen  are  exquisitely 
colored,  presenting  the  Normal  Anatomy  and  Pathology  of  the  Skin,  and  containing  accurate  re- 
presentations of  about  one  hundred  varieties  of  disease,  most  of  them  the  size  of  nature.  Price 
in  cloth.     $5  50. 

In  beauty  of  drawing  and  accuracy  and  finish  of  coloring  these  plates  will  be  found  equal  to 
anything  of  the  kind  as  yet  issued  in  this  country.  The  value  of  the  new  edition  is  enhanced  by 
an  additional  colored  plate. 

The  plates  by  which  this  edition  is  accompanied 
leave  nothing  to  be  desired,  so  far  as  excellence  of 
dtliiicution  and  perfect  accuracy  of  illustration  are 
concerned. — Medico-Chirurgical  Review. 

Ol  these  plates  it  is  impossible  to  sneak  too  highly. 
The  representations  of  the  various  forms  of  cutane- 
ous disease  are  singularly  accurate,  and  the  color- 
ing exceeds  almost  anything  we  have  met  with.— 
Briiiih  and  Foreign  Medical  ReiHtW. 


We  have  already  expressed  our  high  appreciation 
of  Mr.  Wilson's  treatise  on  Diseases  of  the  Skin. 
The  plates  are  comprised  in  a  separate  volume, 
which  we  counsel  all  those  who  possess  the  text  to 
purchase.  It  is  a  beautiful  specimen  of  color  print- 
ing, and  the  representations  of  the  various  forms  of 
skin  disease  are  as  faithful  as  is  possible  in  plates 
of  the  size,.— Boston  Med.  and  Hurg.  Journal,  April 
8,  1858.  ^ 


Also,  the  TEXT  and  PLATES  done  up  in  one  handsome  volume,  extra  cloth,  price  S9  50. 

BY  THE  SAME  AUTHOR. 

THE    DISSECTOR'S  MANUAL;  or,  Practical  and  Surgical  Anatomy.     Third 

American,  from  the  last  revised  and  enlarged  English  edition.  Modirted  and  rearranged,  by 
WiLLiA.M  Hunt,  M.  D.,  Demonstrator  of  Anatomy  in  the  University  ol  Pennsylvania.  In  one 
large  and  handsome  royal  i2mo.  volume,  extracloih,  of  582  pages,  with  I54illustratii)ns.    $2  00. 

BY    THE   SAME   AUTHOa. 

HEALTHY  SKIN;  A  Popular  Treatise  on  the  Skin  and  Hair,  their  Preserva- 
tion and  Management.    Second  American,  from  the  fourth  London  edition.     One  neat  volume 
royal  12mo.,  extra  cloth,  of  about  300  pages,  with  numerous  illustrations.    $1  00.  * 


32 


HENRY   C.   LEA'S  MEDICAL    P  LTBLIC  ATIO  NS. 


WINSLOW    (FORBES),  M.D.,   D.C.L.,   &.c. 
ON  OBSCURE  DISEASES  OF  THE  BRAIN  AND  DISORDERS  OF  THE 

MIND;  their  incipient  Symptomj;,  Palholngy,  Diagnosis,  Treatment,  and  Prophylaxis.     Second 
Ani-'rican,  from  the  third  and  revised  English  edition.     In  one  handsome  octavo  volume,  ol 
nearly  600  peiges,  extra  cloth.     $4  25.     (I\uw  Ready.) 
We  close  this  brief  and  neoessarily  very  imperfect     Patluilogy.    It  completely  exhausts  the  subject,  in 


notice  of  Dr.  Winslow's  great  and  classical  work, 
by  expressing  our  conviction  that  it  is  l<mg  since  so 
important  and  beautifully  written  a  volume  has  is- 
sued from  the  British  medical  preds. — Dublin  Med. 
I'ress,  July  25, 1660. 

We  honestly  believe  this  tobethebest  bookof  the 
season.—  Hanking'' i  Abstract,  July,  lb60. 

Tlie  latter  portion  of  Dr.  Winslow's  work  is  ex- 
clusively devoted  to  the  consideration  of  Cerebral 


ihe  same  manner  as  the  previous  seventeen  chapters 
relating  to  morbid  psychical  phenomena  left  notiiing 
unnoticed  in  reference  to  the  mental  symptoms  pre- 
monitory of  cerebral  disease.  It  is  impossible  to 
overrate  the  benefits  likely  to  result  from  a  general 
perusal  of  Dr.  Win.?low's  valuaole  and  deeply  in- 
teresting work. — London  Lancet,  June  23, 1860. 

It  contains  an  immense  mass  of  information. — 
Brit,  and  For.  Med.-Chir.  Review,  Oct.  1860, 


WEST   (CHARLES),    M .  D., 

Accoucheur  to  and  Lecturer  on  Midwifery  at  St.  Bartholomew's  Hospital,  Physician  to  the  Hospital  for 

Sick  Children,  ice. 

LECTURES  ON  THE  DISEASES  OF  WOMEN.  Second  American,  from  th€ 
second  London  edition.  In  one  handsome  octavo  volume,  extra  cloth,  of  about  500  pages ; 
price  $3  25. 

*«.*  Gentlemen  who  received  the  first  portion,  as  issued  in  the  "Medical  News  and  Library,"  can 
now  complete  their  copies  by  procuring  Part  II,  being  page  309  to  end,  with  Index,  Title  matter, 
&c.,  8vo.,  cloth,  price  $1  25. 


We  mustnow  conclude  this  hastily  written  sketch 
with  tile  confident  assurance  to  our  readers  that  the 
work  will  well  repay  perusal.  The  conscientious, 
painstaking,  practical  physician  isapparent  on  ever> 
page. iV.  Y.  Journal  of  Medicine. 

We  know  of  no  treatise  of  the  kind  so  complete 
and  yet  so  compact.— C/acag-o  Med.  Jour. 

A  fairer,  more  honest,  more  earnest,  and  more  re- 
liable investigator  of  the  many  diseases  of  women 
and  children  is  not  to  be  found  in  any  country.— 
Southern  Med.  and  Surg.  Journal. 

We  have  to  say  of  it,  briefly  and  decidedly,  thai 
it  is  the  best  work  on  the  subject  in  any  language  ; 
and  that  it  stamps  Dr.  West  as  t\\t  facile  princejii 
of  British  obstetric  authors. — Edinb.  Med.  Journ. 


We  gladly  recommend  his  Lectures  as  in  the  high- 
est degree  instructive  to  all  who  are  interested  in 
obstetric  practice. — London  Lancet. 

Happy  in  his  simplicity  of  manner,  and  moderate 
in  his  expression  of  opinion,  the  author  is  a  sound 
reasoner  and  a  good  piactitioner,  and  his  book  is 
worthy  of  the  handsome  garb  in  which  it  has  ap- 
peared.—  Virginia  Med.  Journal. 

We  must  take  leave  of  Dr.  West's  very  useful 
work,  with  our  commendaiion  of  the  clearness  of 
its  style,  and  the  incustry  and  sobriety  of  judgment 
of  which  It  gives  evidence. — London  Med   Times. 

Sound  judgment  and  good  sense  pervade  every 
chapter  of  the  bot)k.  From  its  perusal  we  have  de- 
rived unmixed  satisfaction. — Dublin  Quart.  Juurn. 


BY    THE  SAME   AUTHOR.      {Now  Ready.) 

LECTURES   ON   THE   DISEASES   OF  INFANCY  AND  CHILDHOOD. 

Fourth  American,  from  the  fifth  enlarged  and    improved   London  edition.     In  one  handsome 
octavo  volume,  extra  cloth,  of  about  six  hundred  and  fifty  pages.     $4  00. 

The  numerous  editions  throuffh  which  this  work  has  passed  on  both  sides  of  the  Atlantic,  are 
the  best  eviaeuce  that  it  has  met  a  want  felt  by  the  profession.  Few  practitioners,  indeed,  liave 
had  the  opportunities  o(  observation  and  experience  enjoyed  by  the  author.  In  his  Preface  he 
remarks:  '-The  pre^ent  edition  embodies  the  results  of  1200  recorded  cases,  and  of  nearly  400 
po>t-niortem  examinations,  collected  from  between  30,000  and  40,0L0  children,  who,  during  the  past 
twentv-six  years  have  come  under  my  care, either  in  public  or  in  private  practice."  The  univei^al 
lavor  with  which  the  work  has  been  received  shows  that  the  author  has  made  good  use  of  these 
unusual  advantages. 


The  three  former  editions  of  the  work  now  before 
as  have  placed  the  author  in  tlie  toreinost  rank  of 
those  physicians  who  have  devoted  special  attention 
to  tne  diseases  of  early  life  We  attempt  no  anu- 
1)  sis  of  thisediti'in ,  but  may  refer  the  reader  to  some 
of  the  chapters  to  which  the,  largest  additions  have 
been  made— tlioae  on  Diphtheria,  Disorders  of  the 
Mind,  and  Idiocy,  for  instance — as  a  prooi  that  the 
work  is  really  a  neweditiim;  not  a  mere  reprint. 
In  its  preient  shape  it  will  be  lound  of  the  greatest 
possible  service  in  the  every-day  practice  of  nine- 
tenlhs  of  the  profession.- AZed.  Times  and  Gazette, 
London,  Dec.  10,  la-JO. 

All  things  considired.  this  book  of  Dr.  West  is 
by  far  theliest  treatise  in  our  language  upon  such 
modifications  of  morbid  action  and  disease  as  are 
wijniBsed  when  we  have  to  deal  with  infancy  and 
childhood.  It  is  true  that  it  confines  itself  to  such 
disorders  as  come  within  the  province,  of  the  j/hy- 
ticinn,  and  even  with  respect  to  these  it  is  unequal 
as  regards  minuteness  of  consideration,  and  some 


diseases  it  omits  to  notice  altogether.  But  those 
who  know  anything  of  the  present  condition  of 
pa;diatrics  will  readily  admit  that  it  would  be  next 
to  impossible  to  effect  more,  or  effect  it  better,  than 
the  accoucheur  of  St.  Bartholomew's  has  done  in  a 
single  volume.  The  lecture  {XVI. )  upon  Disurctrs 
of  the  Mind  in  children  is  an  admirable  specimen  of 
the  value  ot  the  Inter  information  conve)  ed  in  tlie 
Lectures  of  Dr.  Charles  West. — London  Lancet, 
Oct.  22,  1859. 

Since  the  appearance  of  the  first  edition,  about 
eleven  years  ago,  the  experience  of  the  author  has 
d(jubl('d;  so  that,  whereas  the  lectures  at  first  were 
founded  on  six  hundred  observaticms,  and  one  hun- 
dred and  eighty  dissecticms  made  among  nearly  four- 
teen thousand  children,  they  now  embody  the  results 
of  nine  hundred  observations,  and  two  hundred  and 
eighty- eight  post- mortem  examinations  made  among 
nearly  thirty  thousand  children,  who,  during  the 
past  tweEty  years,  have  been  under  his  care. — 
British  Med.  Journal,  Oct.  1,  1859. 


BY  THE  SAME  AUTHOE. 


AN  ENQUIRY  INTO  THE  PATHOLOGICAL  IMPORTANCE  OF  ULCER- 
ATION OF  THE  OS  UTERI.    In  one  aeal  octavo  volume,  extra  cioth.    fl  25. 


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